Materiały źródłowe

• #1 Phenylketonuria (PKU) – Diagnosis and treatment – Mayo Clinic

  https://www.mayoclinic.org/diseases-conditions/phenylketonuria/diagnosis-treatment/drc-20376308

  Newborn screening identifies almost all cases of phenylketonuria. All 50 states in the United States require newborns to be screened for PKU. Many other countries also routinely screen infants for PKU. […] If you have PKU or a family history of it, your health care provider may recommend screening tests before pregnancy or birth. It’s possible to identify PKU carriers through a blood test. […] A PKU test is done a day or two after your baby’s birth. For accurate results, the test is done after your baby is 24 hours old and after your baby has had some protein in the diet. […] If this test indicates that your baby may have PKU: Your baby may have additional tests to confirm the diagnosis, including more blood tests and urine tests. You and your baby may have genetic testing to identify the gene change for PKU. […] Phenylketonuria is generally diagnosed through newborn screening. Once your child is diagnosed with PKU, you’ll likely be referred to a medical center or specialty clinic with a specialist who treats PKU and a dietitian with expertise in the PKU diet.

• #1 How do health care providers diagnose phenylketonuria (PKU)? | NICHD – Eunice Kennedy Shriver National Institute of Child Health and Human Development

  http://www.nichd.nih.gov/health/topics/pku/conditioninfo/diagnosed

  Nearly all cases of PKU are diagnosed through a blood test done on newborns. […] All 50 U.S. states and territories require that newborns get screened for PKU. […] Health care providers conduct a PKU screening test using a few drops of blood from a newborns heel. […] If your newborns screening test comes back positive for PKU, your child will need additional tests to confirm that they definitely have the disorder. […] Your health care providers may also suggest genetic testing to look at the mutations in genes that cause PKU. […] In the United States, newborn screening identifies nearly all people born with PKU. […] Because of these rare cases, health professionals recommend PKU testing if a person of any age has developmental delays or an intellectual disability. […] A pregnant woman can request a prenatal DNA test to learn whether their child will be born with PKU.

• #1 Phenylketonuria (PKU) Screening: MedlinePlus Medical TestLock

  https://medlineplus.gov/lab-tests/phenylketonuria-pku-screening/

  A PKU screening test is a blood test given to newborns one to three days after birth. PKU stands for phenylketonuria. It is a rare disorder that prevents the body from breaking down part of a protein called phenylalanine (Phe). […] A PKU screening test diagnoses PKU by measuring the amount of Phe in a blood sample. […] A PKU test is used to see if a newborn has high blood levels of Phe in their blood. This may mean the baby has PKU. More tests may be needed to confirm or rule out a diagnosis. […] Newborns in the United States are required to get a PKU test. A PKU test is usually part of a series of tests called a newborn screening. […] If the results are normal, it means that the amount of Phe in your baby’s blood was normal. So, your baby is unlikely to have PKU. […] If your baby’s results are not normal, it means high levels of Phe were found in your baby’s blood. Your baby most likely has PKU. Your provider may order more tests to confirm or rule out PKU. […] Because PKU is an inherited condition, you and your baby may have genetic testing. Genetic testing shows the type of gene change that’s causing the disease. This information helps your provider understand how serious PKU is and how to treat it.

• #1 PKU Test for Phenylketonuria: Purpose, Procedure, Results

  https://www.webmd.com/children/pku-test

  Your newborn seems perfect. They’ve got 10 fingers and toes and a hearty appetite. But even healthy-looking babies can have problems you cant see. A simple blood test looks for rare conditions, including phenylketonuria (PKU), which can harm your babys growing brain. […] Every baby in the United States is tested for PKU as part of newborn screenings that check for many other conditions, too. […] The test measures the amount of Phe in your babys blood. […] A normal level is less than 2 milligrams per deciliter (mg/dL). More than 4 mg/dL is considered high. Even if your babys results arent in that range, it doesnt necessarily mean they have PKU. It means they need more tests to find out for sure. […] If PKU isnt diagnosed and treated right away, it can cause lasting problems, including developmental delays, lower IQ, mood disorders, hyperactivity, and severe intellectual disability.

• #1 Phenylketonuria: symptoms, treatment, diagnosis and genetics | Medicover Genetics

  https://medicover-genetics.com/phenylketonuria-symptoms-treatment-diagnosis-and-genetics/

  Diagnosis of phenylketonuria through newborn screening is performed in many countries worldwide during the baby’s first days of life. Newborn screening detects certain treatable genetic, endocrine, and metabolic disorders that can affect the long-term health of the baby. The test requires collection of a few drops of blood, usually from the baby’s heel, and if results are positive, meaning phenylalanine levels in the blood are high, further confirmatory tests are performed. […] Babies born with PKU do not initially show symptoms, and PKU is only noticed when brain damage has already occurred. Early treatment prevents symptoms; therefore, identifying PKU as early as possible is vital for the baby’s development. […] Non-invasive prenatal tests (NIPT) can detect PKU during pregnancy, and invasive procedures, like amniocentesis or chorionic villus sampling (CVS) can confirm the finding. As it is an autosomal recessive condition, parents may be carriers without their knowledge, so early testing and detection can be beneficial for prospective parents, allowing them to be informed and prepared.

• #1 Issues in Newborn Screening for Phenylketonuria | AAFP

  https://www.aafp.org/pubs/afp/issues/1999/1001/p1462.html

  The blood sample for phenylketonuria (PKU) screening should be obtained at least 12 hours after the infant’s birth. […] If the first phenylalanine test demonstrates positive results, a repeat test should be performed. […] Occasionally, cases of PKU are missed by newborn screening. Thus, a repeat PKU test should be performed in an infant who exhibits slow development. […] Newborn PKU screening in the United States is performed with the Guthrie inhibition assay or the McCamon-Robins fluorometric test. […] The blood specimen for PKU screening must be obtained at least 12 hours after birth, but in recent years this has proved rather difficult because of changing obstetric practices in which patients are sometimes discharged a few hours after delivery. […] A repeat test must be performed if the initial test is positive.

• #1 The Guthrie Test for Early Diagnosis of Phenylketonuria | Embryo Project Encyclopedia

  https://embryo.asu.edu/pages/guthrie-test-early-diagnosis-phenylketonuria

  The Guthrie test, also called the PKU test, is a diagnostic tool to test infants for phenylketonuria a few days after birth. […] Guthrie’s test detects phenylalanine in the blood of newborns, enabling for early diagnosis of PKU. […] Early diagnoses of PKU prevent the development of mental disabilities in the thousands of individuals affected each year. […] Prior to the creation of the Guthrie test, doctors tested infants for PKU with a less reliable ferric chloride urine test. […] Due to the inaccuracy of the ferric chloride urine test, many infants with PKU went undiagnosed and developed symptoms that persisted throughout their lives. […] Guthrie found that phenylalanine, a chemical found in the blood of people with PKU, reversed -2-Thienylalanine’s inhibition of Bacillus subtilis growth.

• #1 Azthena logo with the word Azthena

  https://www.news-medical.net/health/Diagnosis-of-PKU.aspx

  Tandem mass spectrometry (MS) this test has similar reliability as fluorometric analysis. It can also find the levels of tyrosine. […] Thus this test gives a more accurate picture of the condition. […] Sometimes carrier status of the disease among parents and in a baby may also be detected using biochemical parameters rather than genetic testing. […] This is done using ratios of Phenylalanine and tyrosine in blood. […] Molecular testing includes looking at the phenylalanine hydroxylase deficiency via the activity and functioning of the PAH gene on the 12th chromosome. […] These can predict nearly 30-50% of genetic defects in the PAH gene. […] Some parents may need genetic diagnosis of carrier status for PKU before conception especially if the condition has been seen in the family.

• #1 Newborn screening information for classic phenylketonuria | Baby’s First Test | Newborn Screening | Baby Health

  https://www.babysfirsttest.org/newborn-screening/conditions/classic-phenylketonuria-pku

  If phenylketonuria (PKU) is detected at birth, early treatment can prevent the signs of the condition mentioned in the Early Signs section. […] If treatment is started after six months of age, babies are at risk for severe intellectual disabilities. […] It is important to treat PKU, even if treatment is started after noticing signs and symptoms, in order to help prevent permanent brain damage. […] PKU is an autosomal recessive genetic condition. This means that a child must inherit two copies of the non-working gene for PKU, one from each parent, in order to have the condition.

• #1 Other Phenylketonuria (PKU) FAQs | NICHD – Eunice Kennedy Shriver National Institute of Child Health and Human Development

  http://www.nichd.nih.gov/health/topics/pku/more_information/other-faqs

  A blood sample can be used to test for the mutations that cause PKU. […] A blood test that measures the phenylalanine in an infants blood is enough to help make a PKU diagnosis. Therefore, DNA testing is not necessary. However, if a child tests positive for PKU, health care providers may recommend genetic testing because identifying the type of mutation involved can help guide selection of the most appropriate treatment plan. […] A DNA test also should be performed on a child if both parents are PKU carriers and the standard newborn blood test does not show the condition. The test will definitively indicate or rule out PKU, if the disease-causing mutations in the family have been identified. […] A pregnant woman can request a prenatal DNA test to learn whether their child will be born with PKU.

• #1 Phenylketonuria (PKU) Gene Sequencing | Test Detail | Quest Diagnostics

  https://testdirectory.questdiagnostics.com/test/test-detail/16152/phenylketonuria-pku-gene-sequencing?p=r&cc=MASTER

  Whole blood: Normal phlebotomy procedure. Specimen stability is crucial. Store and ship at room temperature immediately. Do not freeze. […] For fetal testing:1) Please call 1-866-GENE-INFO (1-866-436-3463) prior to submission.2) Documentation of parental carrier status must be provided.3) It is required that Maternal Cell Contamination Study, STR Analysis be ordered in conjunction with fetal testing. A separate tube of maternal blood (EDTA) is required for this test. […] Amniotic fluid: Normal collection procedure. Specimen stability is crucial. Store and ship at room temperature immediately. Do not refrigerate or freeze; forward to laboratory when sample arrives. […] Specimen stability is crucial. Store and ship at room temperature immediately. Do not refrigerate or freeze; forward to laboratory when sample arrives.

• #1 Phenylketonuria – Genomics Education Programme

  https://www.genomicseducation.hee.nhs.uk/documents/phenylketonuria/

  Phenylkentonuria (PKU) is an autosomal recessive condition that prevents the body from metabolising the amino acid phenylalanine to tyrosine, due to a deficiency in the enzyme phenylalanine hydroxylase. […] Biochemical testing for the diagnosis of PKU is based on elevated levels of blood phenylalanine. […] PKU can also be diagnosed using tandem mass spectrometry, as part of the NHS newborn blood spot screening programme in England. This method is used to detect high concentrations of phenylalanine and low concentrations of tyrosine. […] Genetic testing can be used to confirm the diagnosis by detecting the pathogenic PAH variants, which can also be used for carrier detection. […] Prenatal or preimplantation genetic diagnosis requires the pathogenic variant in both parents to be identified.

• #1 Phenylketonuria (PKU) Workup: Approach Considerations, Laboratory Studies, Magnetic Resonance Imaging

  https://emedicine.medscape.com/article/947781-workup

  A qualified laboratory should measure plasma phenylalanine and tyrosine, either in isolation or in a plasma amino acid assay. Standard recommendations call for fasting for 3-4 hours prior to obtaining a sample for plasma amino acid analysis. A qualified laboratory should perform blood and urine analysis of biopterin and neopterins in order to rule out defects of biopterin synthesis or recycling. In the modern era, gene sequencing is usually performed, which establishes a precise molecular diagnosis as well as expanding knowledge of genotype-phenotype correlations in PKU. […] Prenatal diagnosis is available but rarely used because the disorder is so treatable. Prenatal diagnosis can be accomplished by DNA mutation analysis following chorionic villous sampling or amniocentesis. […] Perform screening on blood samples during the first week of life. Wide variability in phenylalanine concentrations in a 24-hour period in children with PKU may necessitate repeat screening. Screening for PKU involves the following: Determination of phenylalanine levels, the standard amino acid analysis done by means of ion exchange chromatography or tandem mass spectrometry.

• #1 Phenylketonuria

  https://www.nhs.uk/conditions/phenylketonuria/

  Phenylketonuria (PKU) is a rare but potentially serious inherited disorder. […] At around 5 days old, babies are offered newborn blood spot screening to test for PKU and many other conditions. […] If PKU is confirmed, treatment will be given straight away to reduce the risk of serious complications. […] With early diagnosis and the correct treatment, most children with PKU are able to live healthy lives. […] A child with phenylketonuria will need regular blood tests to measure levels of phenylalanine in their blood and assess how well they’re responding to treatment. […] It’s recommended that children who are: 1 year or younger should have their blood tested once a week; between 1 and 12 years should have their blood tested every 2 weeks; over 12 years should have their blood tested once a month.

• #1 Phenylketonuria: What Is It?

  https://www.webmd.com/digestive-disorders/phenylketonuria-overview

  PKU happens when there’s a problem with a gene that’s involved in the breakdown of Phe. […] Many countries, including the U.S., test newborns for PKU. It’s done through a simple blood test that happens a day or two after they’re born. A health care worker at the hospital usually takes the blood through a prick in your babys heel. Its put on a special paper and sent to a lab. Your babys doctor will share the results with you. […] The main way to treat PKU is with a low-protein diet. […] You should stay on treatment for life. If you go off the diet, you may have some memory loss, trouble concentrating, or you might feel anxious or depressed. If you stick with or go back on the diet, your mind will be sharper and youll feel better. […] You need to check the Phe levels in your blood often. This shows if your treatment is working. It also lowers the chance of brain, mood, and social problems. You usually check an infants levels once or twice a week by taking the blood sample from a tiny prick in the heel. In older kids and adults, you take the blood from a fingertip. You put the drop of blood on a card and mail it to a lab. If your level is off, your treatment team will work with you to bring it into a safe range.

• #1 Phenylketonuria (PKU) – Pediatrics – Merck Manual Professional Edition

  https://www.merckmanuals.com/professional/pediatrics/inherited-disorders-of-metabolism/phenylketonuria-pku

  Phenylketonuria is a disorder of amino acid metabolism that causes a clinical syndrome of intellectual disability with cognitive and behavioral abnormalities caused by elevated serum phenylalanine. Diagnosis is by detecting high phenylalanine levels and normal or low tyrosine levels. […] In the United States and many other countries, all neonates are screened for phenylketonuria 24 to 48 hours after birth with one of several blood tests; abnormal results are confirmed by directly measuring phenylalanine levels. […] Treatment is lifelong dietary phenylalanine restriction; adequate treatment begun in the first days of life prevents many manifestations of the disease. […] Although prognosis is excellent with treatment, frequent monitoring of plasma phenylalanine levels is required; recommended targets are between 2 mg/dL and 6 mg/dL (120 to 360 micromol/L) for all children.

• #1 Phenylketonuria

  https://www.nhs.uk/conditions/phenylketonuria/

  Many adults with PKU find they function best while on a low-protein diet. […] For women with PKU, it’s essential that they return to a strict diet if they’re considering becoming pregnant, as high phenylalanine levels can harm an unborn child. […] Provided that phenylalanine levels are strictly controlled during pregnancy, problems can be avoided and there’s no reason why a woman with PKU should not be able to have a normal, healthy baby.

• #1 Phenylketonuria (PKU)

  https://www2.hse.ie/conditions/heel-prick-screening/conditions/phenylketonuria-pku/

  Phenylketonuria (PKU) is a rare but potentially serious inherited disorder. […] About 1 in 4,500 babies born in Ireland has PKU. With early diagnosis and treatment most go on to live healthy lives. […] Babies can have heel prick screening at around 5 days old. This is to check if they have PKU or other conditions. […] If PKU is confirmed, treatment will be given straight away. This is to reduce the risk of complications. Treatment includes a special diet and regular blood tests. […] A child with PKU needs regular blood tests. This is to measure levels of phenylalanine and to see if they’re responding to treatment. […] In some cases, doctors may prescribe a medicine called sapropterin. This can help to break down phenylalanine so it will not build up in the blood. […] Women with PKU have to take special care during pregnancy. This is because high levels of phenylalanine can hurt an unborn baby. […] If phenylalanine levels are controlled problems can be avoided. Women with PKU are able to have normal, healthy babies.

• #1 The complete European guidelines on phenylketonuria: diagnosis and treatment | Orphanet Journal of Rare Diseases | Full Text

  https://ojrd.biomedcentral.com/articles/10.1186/s13023-017-0685-2

  Individuals who have not had NBS and present with developmental delay or other PKU-related symptoms, should have plasma amino acids analysed. […] The differential diagnosis of HPA includes high natural protein intake, prematurity, defects in BH4 metabolism and liver disease. […] Patient genotyping is not essential for the diagnosis of PKU but the genotype can determine the degree of protein dysfunction, residual PAH activity and consequently the metabolic phenotype. […] In 1990, Smith et al. showed that every 4 weeks delay in starting treatment caused a decline of IQ score by approximately 4 points, underscoring the knowledge that neurological damage starts early after birth. […] There is unanimity in the literature and among professionals that patients with untreated blood Phe concentrations 600 mol/l should be treated.

• #1 Phenylketonuria (PKU) Workup: Approach Considerations, Laboratory Studies, Magnetic Resonance Imaging

  https://emedicine.medscape.com/article/947781-workup

  Abnormal newborn screening results require immediate follow-up in accordance with local regulations. Less-prominent elevations of phenylalanine or ambiguous results may require repeat screening. More significant elevations still require definitive testing and referral to a metabolic treatment facility experienced with PKU. […] Results of urine tests (ie, ferric chloride test) may be negative in the first month of life and are rarely used in current practice. It is important to measure erythrocyte dihydropteridine reductase and urine neopterin and biopterin. […] Cranial magnetic resonance imaging studies may be recommended for older individuals with poor dietary control and motor or cognitive deficits, or in cases of behavioral, cognitive, or psychiatric concerns. Common white matter changes can show reversibility with improved diet and reduced phenylalanine levels, affecting brain structures like the cerebrum, corpus callosum, hippocampus, and pons. […] Some research suggests that measuring brain phenylalanine levels through magnetic resonance spectroscopy could be more predictive of outcomes than blood levels, although the utility of this advanced technology remains debated and limited to select centers.

• #1 Phenylketonuria (PKU)

  https://healthlibrary.tidelandshealth.org/Library/TestsProcedures/167,pku

  Babies are often screened for PKU with a heel-prick test. This is done by getting a few drops of blood from the infant’s heel. […] The blood test may give a false-positive or false-negative result in certain cases: Your baby is premature or has liver problems. This could lead to a false-positive result because certain liver enzymes have not fully started working. […] The test should not be done before 24 hours after birth.

• #1 Phenylketonuria (PKU)

  https://healthlibrary.uwmedicine.org/Library/PreventionGuidelines/167,pku

  The blood test may give a false-positive or false-negative result in certain cases: Your baby is premature or has liver problems. This could lead to a false-positive result because certain liver enzymes have not fully started working. […] Your baby has feeding problems, such as vomiting. This could give a false-negative result. […] Medicines, such as aspirin or antibiotics, may affect the results of the urine test for PKU.

• #1 Phenylketonuria (PKU)

  https://healthlibrary.inova.org/SummerHeat/167,pku

  Babies are often screened for PKU with a heel-prick test. […] The blood test may give a false-positive or false-negative result in certain cases: Your baby is premature or has liver problems. This could lead to a false-positive result because certain liver enzymes have not fully started working. […] Medicines, such as aspirin or antibiotics, may affect the results of the urine test for PKU.

• #1

  https://www.cdc.gov/mmwr/preview/mmwrhtml/00000243.htm

  Screening for phenylketonuria (PKU) and congenital hypothyroidism (CH) is of concern to parents, physicians, and public health professionals. […] The Committee believes that screening is not the equivalent of diagnosis; some cases of PKU and CH will inevitably be missed by screening. […] A blood SAMPLE should be obtained from every infant before he/she leaves the nursery, regardless of age. […] Infants initially screened before 24 hours of age should be rescreened for PKU/PHP because the probability of missing cases by the initial screening test is greatly increased. […] Accurate ANALYSIS requires meticulous standardization of the screening method. […] All patients with persistent hyperphenylalaninemia should be investigated to rule out the tetrahydrobiopterin-deficient forms of PKU.

• #1

  https://www.cdc.gov/mmwr/preview/mmwrhtml/00000243.htm

  Early diagnosis and treatment largely prevent the mental retardation associated with untreated PKU, and a properly executed program is clearly cost effective. […] Programs that reach every infant, perform the test reliably, provide timely follow-up of subjects with positive tests, assure accurate diagnosis, and provide appropriate counseling and treatment conform to published guidelines. […] Cases of PKU have been missed because the level of blood phenylalanine was not elevated above normal, even after the third day of life. […] In general, however, the chance of false-negative test results for PKU and other forms of PHP is greater when the blood sample is obtained before 72 hours of age. […] It is now firmly established that cord blood cannot be used for PKU/PHP screening. […] Accurate analysis of the sample is a critical facet of prevention. […] Infants with disorders of tetrahydrobiopterin homeostasis are likely to experience progressive neurologic deterioration when treated with low-phenylalanine diet alone.

• #1 Newborn screening information for classic phenylketonuria | Baby’s First Test | Newborn Screening | Baby Health

  https://www.babysfirsttest.org/newborn-screening/conditions/classic-phenylketonuria-pku

  Phenylketonuria (PKU) is a condition in which the body cannot break down one of the amino acids found in proteins. […] If left untreated, PKU can cause brain damage or even death. However, if the condition is detected early and treatment is begun, individuals with PKU can lead healthy lives. […] If your babys newborn screening result for phenylketonuria (PKU) was out of the normal range, your babys doctor or the state screening program will contact you to arrange for your baby to have additional testing. It is important to remember that an out-of-range screening result does not necessarily mean that your child has the condition. […] Follow-up testing will involve checking your babys urine and blood samples for harmful levels of acids and toxins. […] High amounts phenylalanine in the blood might indicate that your baby has PKU.

• #1 Issues in Newborn Screening for Phenylketonuria | AAFP

  https://www.aafp.org/pubs/afp/issues/1999/1001/p1462.html

  When the initial newborn screening test and the second test show positive results, a confirmatory quantitative test, such as the McCamon-Robins fluorometric test, should be performed by a laboratory at a referral metabolic center. […] If a positive test is overlooked and the infant is subsequently found to have PKU, a malpractice lawsuit is almost certain to follow. […] If it becomes evident during regular follow-up of an infant that the infant’s development is delayed, it is useful to examine the report of PKU screening, and consideration may be given to repeating the test. […] With early diagnosis of PKU and institution of the phenylalanine-restricted diet, the prognosis for intellectual development in affected children is excellent.

• #1 Phenylketonuria (PKU) | Texas DSHS

  https://www.dshs.texas.gov/newborn-screening-program/newborn-screening-parent-resources/phenylketonuria-pku

  Phenylketonuria (PKU) is a condition some children have that affects their ability to properly use protein from their food. […] Severe intellectual disabilities and other problems resulting from PKU can be prevented by early diagnosis and proper diet control. […] PKU cannot be cured but can be treated if a special diet is started early in the newborn period. Current research indicates that the special diet should be continued at least through adolescence and possibly throughout life. […] The Texas Department of State Health Services provides, without charge to residents of Texas who are diagnosed with PKU, blood specimen analysis through the Texas Department of State Health Services Laboratory in Austin.

• #1

  https://www.gov.uk/government/publications/pku-suspected-description-in-brief/phenylketonuria-pku-detailed-information

  This information is for parents if their baby is suspected of having PKU or has been diagnosed with PKU following their newborn blood spot screening test (heel prick test). It will help you and your health professionals to talk through the next stages of your babys care. […] When your baby was about 5 days old, your midwife took some blood from your babys heel for their newborn blood spot screening test (the heel prick test). The newborn blood spot screening test measures the amount of some amino acids in the blood. A high level of the amino acid phenylalanine suggests your baby may have PKU. This is called a screen positive result. […] If your baby has a screen positive result, you will be seen by a metabolic doctor, dietitian and nurse specialist (the metabolic team). The team will provide advice and support. Blood tests will be carried out to confirm if your baby has PKU. […] With good dietary treatment and well controlled blood phenylalanine levels, the outcome is usually very good and most children will avoid any long-term health problems.

• #1 What is PKU: Symptoms and Diagnosis

  https://www.apr.ch/apr-pharma-products/therapeutic-pharma/what-is-pku/

  The treatment involves a particularly restricted and lifelong diet whose aim is to keep low Phe levels in the blood. […] European guidelines for PKU suggest consuming traditional protein substitutes in small and frequent doses at least 3/4 times per day. […] International experts agree that further changes are needed for protein substitutes to be improved and really make a difference in the lives of people living and dealing with PKU.

• #1 Other Phenylketonuria (PKU) FAQs | NICHD – Eunice Kennedy Shriver National Institute of Child Health and Human Development

  http://www.nichd.nih.gov/health/topics/pku/more_information/other-faqs

  If a child is diagnosed with PKU, other family members may be more likely to conceive children who also will have PKU. […] If you have PKU, it is very important to follow a strict low-phenylalanine diet before becoming pregnant and throughout your pregnancy. […] Infants and children with PKU need frequent blood tests to measure the phenylalanine in their blood. Their health care provider may suggest changes to the diet or formula the child receives if there is evidence of too much or too little phenylalanine.

• #1 The complete European guidelines on phenylketonuria: diagnosis and treatment | Orphanet Journal of Rare Diseases | Full Text

  https://ojrd.biomedcentral.com/articles/10.1186/s13023-017-0685-2

  The evidence regarding initiation of treatment with blood Phe concentrations between 360 and 600 mol/l is inconsistent. […] The evidence that supports treatment is of suboptimal quality. […] Since the introduction of NBS and early treatment, patients with PKU no longer develop profound and irreversible intellectual disability. […] The foremost question now is if patients should be treated throughout adulthood. […] As there is currently no strong evidence that it is safe to discontinue dietary treatment in adults, treatment for life is recommended. […] In PKU, life-long, systematic follow-up is recommended independent of the degree of adherence and (non-) treatment choice, to screen for long-term complications at any life stage, and provide appropriate support to patients. […] The primary goal of treatment is normal neurocognitive and psychosocial functioning.

• #1 What is PKU: Symptoms and Diagnosis

  https://www.apr.ch/apr-pharma-products/therapeutic-pharma/what-is-pku/

  Phenylketonuria, or PKU for short, is a rare autosomal recessive inborn error of phenylalanine (Phe) metabolism disorder that approximately 1:15.000 people in the world are born with. […] Early diagnosis and prompt intervention can enable people with PKU to grow up healthily and live a normal life, attain expected educational standards, and lead independent lives as adults. […] Testing for PKU is typically done during newborn screening (NBS) about 24-72 hours after birth in the hospital, taking a blood sample from the heel of the foot and measuring blood Phe levels through a simple laboratory test. […] PKU is a genetic condition, and it can’t be prevented or avoided. […] Pregnancies in PKU should be planned. Women with PKU can have healthy children as long as they maintain strict adherence to their low Phe diet during their pregnancy.

• #2 Phenylketonuria (PKU) – Symptoms and causes – Mayo Clinic

  https://www.mayoclinic.org/diseases-conditions/phenylketonuria/symptoms-causes/syc-20376302

  Babies in the United States and many other countries are screened for PKU soon after birth. […] Although there is no cure for PKU, recognizing PKU and starting treatment right away can help prevent limitations in areas of thinking, understanding and communicating (intellectual disability) and major health problems. […] If routine newborn screening tests show that your baby may have PKU, your child’s health care provider will want to start dietary treatment right away to prevent long-term problems. […] It’s especially important for women with a history of PKU to see a health care provider and maintain the PKU diet before becoming pregnant and during pregnancy. This reduces the risk of high blood phenylalanine levels harming their unborn babies. […] Adults with PKU who have stopped the PKU diet in their teens may benefit from a visit with their health care providers. Returning to the diet may improve mental functioning and behavior and prevent further damage to the central nervous system that can result from high phenylalanine levels.

• #2 Phenylketonuria (PKU) Screening: MedlinePlus Medical TestLock

  https://medlineplus.gov/lab-tests/phenylketonuria-pku-screening/

  A PKU screening test is a blood test given to newborns one to three days after birth. PKU stands for phenylketonuria. It is a rare disorder that prevents the body from breaking down part of a protein called phenylalanine (Phe). […] A PKU screening test diagnoses PKU by measuring the amount of Phe in a blood sample. […] A PKU test is used to see if a newborn has high blood levels of Phe in their blood. This may mean the baby has PKU. More tests may be needed to confirm or rule out a diagnosis. […] Newborns in the United States are required to get a PKU test. A PKU test is usually part of a series of tests called a newborn screening. […] If the results are normal, it means that the amount of Phe in your baby’s blood was normal. So, your baby is unlikely to have PKU. […] If your baby’s results are not normal, it means high levels of Phe were found in your baby’s blood. Your baby most likely has PKU. Your provider may order more tests to confirm or rule out PKU. […] Because PKU is an inherited condition, you and your baby may have genetic testing. Genetic testing shows the type of gene change that’s causing the disease. This information helps your provider understand how serious PKU is and how to treat it.

• #2 Phenylketonuria (PKU): Symptoms, Causes & Treatment

  https://my.clevelandclinic.org/health/diseases/17816-phenylketonuria

  Healthcare providers confirm a diagnosis of phenylketonuria (PKU) shortly after birth as part of routine newborn screening via a blood test. If your babys phenylalanine levels in their blood sample are high, your provider will administer additional tests to confirm the diagnosis and the type of PKU, normally with additional blood or urine tests. Since PKU is a genetic condition, a genetic test can pinpoint the mutation responsible for symptoms. […] Although the majority of PKU diagnoses occur shortly after a baby is born, providers can diagnose PKU at any age if newborn screenings werent completed. […] A phenylalanine screening test identifies levels of phenylalanine in your blood. Newborns receive this test between 24 to 72 hours after birth as part of the newborn screen. Your healthcare provider will take a sample of blood from your babys heel by poking it with a small needle. Only a few drops of blood are necessary for this test.

• #2 Phenylketonuria (PKU)

  https://healthlibrary.tidelandshealth.org/Library/TestsProcedures/167,pku

  PKU screening, Guthrie assay, PKU test […] This is a blood test to screen newborns for phenylketonuria (PKU). PKU is a condition that can cause brain damage and severe intellectual disability if it goes untreated. […] All U.S. states screen newborn babies for PKU. This means that almost all cases are now found and treatment started at birth. […] Your child may need this test because finding and starting treatment of PKU in a newborn can prevent intellectual disability and other developmental problems in your child. […] Even though most babies with PKU are diagnosed soon after birth, screening for PKU should be considered for any child who has an intellectual disability or is developmentally delayed. […] The test screens for blood levels of phenylalanine. Normal levels of phenylalanine in the blood are less than 2 milligrams per deciliter (mg/dL). More than 4 mg/dL of phenylalanine in the blood is considered high and may mean your child has PKU.

• #2 Newborn screening information for classic phenylketonuria | Baby’s First Test | Newborn Screening | Baby Health

  https://www.babysfirsttest.org/newborn-screening/conditions/classic-phenylketonuria-pku

  Phenylketonuria (PKU) is a condition in which the body cannot break down one of the amino acids found in proteins. […] If left untreated, PKU can cause brain damage or even death. However, if the condition is detected early and treatment is begun, individuals with PKU can lead healthy lives. […] If your babys newborn screening result for phenylketonuria (PKU) was out of the normal range, your babys doctor or the state screening program will contact you to arrange for your baby to have additional testing. It is important to remember that an out-of-range screening result does not necessarily mean that your child has the condition. […] Follow-up testing will involve checking your babys urine and blood samples for harmful levels of acids and toxins. […] High amounts phenylalanine in the blood might indicate that your baby has PKU.

• #2

  https://www.cdc.gov/mmwr/preview/mmwrhtml/00000243.htm

  Screening for phenylketonuria (PKU) and congenital hypothyroidism (CH) is of concern to parents, physicians, and public health professionals. […] The Committee believes that screening is not the equivalent of diagnosis; some cases of PKU and CH will inevitably be missed by screening. […] A blood SAMPLE should be obtained from every infant before he/she leaves the nursery, regardless of age. […] Infants initially screened before 24 hours of age should be rescreened for PKU/PHP because the probability of missing cases by the initial screening test is greatly increased. […] Accurate ANALYSIS requires meticulous standardization of the screening method. […] All patients with persistent hyperphenylalaninemia should be investigated to rule out the tetrahydrobiopterin-deficient forms of PKU.

• #2 Azthena logo with the word Azthena

  https://www.news-medical.net/health/Diagnosis-of-PKU.aspx

  Tandem mass spectrometry (MS) this test has similar reliability as fluorometric analysis. It can also find the levels of tyrosine. […] Thus this test gives a more accurate picture of the condition. […] Sometimes carrier status of the disease among parents and in a baby may also be detected using biochemical parameters rather than genetic testing. […] This is done using ratios of Phenylalanine and tyrosine in blood. […] Molecular testing includes looking at the phenylalanine hydroxylase deficiency via the activity and functioning of the PAH gene on the 12th chromosome. […] These can predict nearly 30-50% of genetic defects in the PAH gene. […] Some parents may need genetic diagnosis of carrier status for PKU before conception especially if the condition has been seen in the family.

• #2 Phenylketonuria: symptoms, treatment, diagnosis and genetics | Medicover Genetics

  https://medicover-genetics.com/phenylketonuria-symptoms-treatment-diagnosis-and-genetics/

  PKU is a genetic disorder that is caused by variants in the PAH gene. These variants cause an absence or deficiency of the enzyme phenylalanine hydroxylase that is responsible for processing phenylalanine. Without phenylalanine hydroxylase, phenylalanine levels build up causing the symptoms of PKU. […] Genetic testing can be used to identify the causative variant.

• #2 Phenylketonuria (PKU): Causes, Symptoms, Diagnosis, and Treatment • Yesil Health

  https://yesilhealth.com/your-health/phenylketonuria-pku-causes-symptoms-diagnosis-and-treatment/

  Phenylketonuria (PKU) is a genetic disorder that requires lifelong management to prevent intellectual disability and other serious health problems. […] PKU can be diagnosed through a combination of newborn screening tests and genetic testing. […] Newborn babies are typically screened for PKU at birth using a blood test. This test measures the levels of phenylalanine in the blood, and if the levels are elevated, further testing is done to confirm the diagnosis. […] The most common newborn screening test for PKU is the Guthrie test, which measures the levels of phenylalanine in the blood. If the test results show high levels of phenylalanine, further testing is needed to confirm the diagnosis. […] Genetic testing can confirm the diagnosis of PKU and identify the specific mutation in the PAH gene. This is usually done through a blood test or a cheek swab. […] Early diagnosis and treatment are critical for managing PKU and preventing intellectual disability and other serious health problems.

• #2 The Guthrie Test for Early Diagnosis of Phenylketonuria | Embryo Project Encyclopedia

  https://embryo.asu.edu/pages/guthrie-test-early-diagnosis-phenylketonuria

  The Guthrie test, also called the PKU test, is a diagnostic tool to test infants for phenylketonuria a few days after birth. […] Guthrie’s test detects phenylalanine in the blood of newborns, enabling for early diagnosis of PKU. […] Early diagnoses of PKU prevent the development of mental disabilities in the thousands of individuals affected each year. […] Prior to the creation of the Guthrie test, doctors tested infants for PKU with a less reliable ferric chloride urine test. […] Due to the inaccuracy of the ferric chloride urine test, many infants with PKU went undiagnosed and developed symptoms that persisted throughout their lives. […] Guthrie found that phenylalanine, a chemical found in the blood of people with PKU, reversed -2-Thienylalanine’s inhibition of Bacillus subtilis growth.

• #2 The Guthrie Test for Early Diagnosis of Phenylketonuria | Embryo Project Encyclopedia

  https://embryo.asu.edu/pages/guthrie-test-early-diagnosis-phenylketonuria

  If the blood sample contained phenylalanine, Bacillus subtilis grew around the blood sample and indicated that patient had PKU. […] Guthrie found that the bacterial inhibition assay worked with infant’s heel blood. […] Guthrie’s test identified 275 infants as presumptive positive for PKU, meaning they were likely to have PKU. […] Of those 275 infants presumed positive for PKU, thirty-seven cases of PKU were confirmed by repeating the Guthrie test and using a quantitative blood assay, meaning the test was effective. […] By the twenty-first century, all fifty US states required hospitals to test newborns for PKU, and the Guthrie test was used in many places throughout the world.

• #2 Azthena logo with the word Azthena

  https://www.news-medical.net/health/Diagnosis-of-PKU.aspx

  Newborns who are diagnosed with phenylalanine hydroxylase deficiency may show no initial symptoms or signs. […] When there is phenylalanine hydroxylase deficiency the blood and plasma levels of phenylalanine rise. This is more often than not diagnostic of the condition of PKU or phenylketonuria. […] Plasma levels of phenylalanine are consistently over 120 mol/L (2 mg/dL) before therapy is initiated. […] If the levels of phenylalanine is high in blood it shows up in the card. In case of a first positive test, a second test is needed. […] Once the test shows positive second time, further tests are needed to confirm the diagnosis. […] Tests at birth include Guthrie card bacterial inhibition assay (BIA) this is an inexpensive, simple and easy-to-use test that is applied routinely. […] Fluorometric analysis This requires machinery that tests the blood for raised levels of phenylalanine. This shows more accurate results than the BIA.

• #2 Newborn Screening Program – Phenylketonuria

  http://www.idph.state.il.us/healthwellness/fs/pku.htm

  Phenylketonuria (PKU) is a disorder of amino acid metabolism that results in excess levels of phenylalanine in body fluids. Elevated levels of phenylalanine can become neurotoxic; early detection and treatment of hyperphenylalaninemia is necessary to prevent mental retardation. […] Recently in Illinois, tandem mass spectrometry (MS/MS) has been implemented to provide newborn screening for PKU and hyperphenylalaninemia. This new laboratory technology has replaced the fluorometric analysis previously utilized for PKU screening. […] When receiving a presumptive positive result (elevated phenylalanine level), the clinician should immediately check on the clinical status of the baby and refer the infant to a metabolic disease specialist. […] Early diagnosis and treatment is essential to prevent developmental delays.

• #2 Other Phenylketonuria (PKU) FAQs | NICHD – Eunice Kennedy Shriver National Institute of Child Health and Human Development

  http://www.nichd.nih.gov/health/topics/pku/more_information/other-faqs

  A blood sample can be used to test for the mutations that cause PKU. […] A blood test that measures the phenylalanine in an infants blood is enough to help make a PKU diagnosis. Therefore, DNA testing is not necessary. However, if a child tests positive for PKU, health care providers may recommend genetic testing because identifying the type of mutation involved can help guide selection of the most appropriate treatment plan. […] A DNA test also should be performed on a child if both parents are PKU carriers and the standard newborn blood test does not show the condition. The test will definitively indicate or rule out PKU, if the disease-causing mutations in the family have been identified. […] A pregnant woman can request a prenatal DNA test to learn whether their child will be born with PKU.

• #2 Phenylketonuria (PKU) Gene Sequencing | Test Detail | Quest Diagnostics

  https://testdirectory.questdiagnostics.com/test/test-detail/16152/phenylketonuria-pku-gene-sequencing?p=r&cc=MASTER

  Phenylketonuria (PKU) Gene Sequencing – 1. To identify disease-causing variants in individuals affected with PKU. 2. To identify carriers in high risk ethnic groups or people with a positive family history. 3. Prenatal diagnosis of PKU. […] This test was developed and its analytical performance characteristics have been determined by Quest Diagnostics. It has not been cleared or approved by FDA. This assay has been validated pursuant to the CLIA regulations and is used for clinical purposes. […] 5 mL whole blood collected in an EDTA (lavender-top) tube, EDTA (royal blue-top) tube, ACD (yellow-top) tube or sodium heparin (green-top) tube. […] Do not hold specimen; forward to laboratory when specimen arrives. Contact performing laboratory for stability determination. For any other sample type call 866-GENE-INFO (1-866-436-3463).

• #2 How do health care providers diagnose phenylketonuria (PKU)? | NICHD – Eunice Kennedy Shriver National Institute of Child Health and Human Development

  http://www.nichd.nih.gov/health/topics/pku/conditioninfo/diagnosed

  Nearly all cases of PKU are diagnosed through a blood test done on newborns. […] All 50 U.S. states and territories require that newborns get screened for PKU. […] Health care providers conduct a PKU screening test using a few drops of blood from a newborns heel. […] If your newborns screening test comes back positive for PKU, your child will need additional tests to confirm that they definitely have the disorder. […] Your health care providers may also suggest genetic testing to look at the mutations in genes that cause PKU. […] In the United States, newborn screening identifies nearly all people born with PKU. […] Because of these rare cases, health professionals recommend PKU testing if a person of any age has developmental delays or an intellectual disability. […] A pregnant woman can request a prenatal DNA test to learn whether their child will be born with PKU.

• #2 Phenylketonuria – UF Health

  https://ufhealth.org/conditions-and-treatments/phenylketonuria

  Phenylketonuria (PKU) is a rare condition in which a baby is born without the ability to properly break down an amino acid called phenylalanine. […] PKU can be easily detected with a simple blood test. All states in the United States require a PKU screening test for all newborns as part of the newborn screening panel. The test is generally done by taking a few drops of blood from the baby before the baby leaves the hospital. […] If the screening test is positive, further blood and urine tests are required to confirm the diagnosis. Genetic testing is also done. […] An enzyme assay or genetic testing can determine if parents carry the gene for PKU. Chorionic villus sampling or amniocentesis can be done during pregnancy to test the unborn baby for PKU.

• #2 Phenylketonuria (PKU) Workup: Approach Considerations, Laboratory Studies, Magnetic Resonance Imaging

  https://emedicine.medscape.com/article/947781-workup

  A qualified laboratory should measure plasma phenylalanine and tyrosine, either in isolation or in a plasma amino acid assay. Standard recommendations call for fasting for 3-4 hours prior to obtaining a sample for plasma amino acid analysis. A qualified laboratory should perform blood and urine analysis of biopterin and neopterins in order to rule out defects of biopterin synthesis or recycling. In the modern era, gene sequencing is usually performed, which establishes a precise molecular diagnosis as well as expanding knowledge of genotype-phenotype correlations in PKU. […] Prenatal diagnosis is available but rarely used because the disorder is so treatable. Prenatal diagnosis can be accomplished by DNA mutation analysis following chorionic villous sampling or amniocentesis. […] Perform screening on blood samples during the first week of life. Wide variability in phenylalanine concentrations in a 24-hour period in children with PKU may necessitate repeat screening. Screening for PKU involves the following: Determination of phenylalanine levels, the standard amino acid analysis done by means of ion exchange chromatography or tandem mass spectrometry.

• #2 PKU (Phenylketonuria) | familydoctor.org

  https://familydoctor.org/condition/phenylketonuria-pku/

  Nearly all cases of PKU are diagnosed through this newborn blood test. […] Rarely, PKU could be missed during the screening process. For this reason, people of any age who have developmental delays or an intellectual disability are often tested for PKU. […] PKU can also be diagnosed before the baby is born. A pregnant woman can request genetic testing be done to see if her unborn baby will have the disease. This is done through amniocentesis or chorionic villus sampling. This testing can be useful if the parents already have one child with PKU. Their chances of having another child with the condition are higher than average.

• #2 Other Phenylketonuria (PKU) FAQs | NICHD – Eunice Kennedy Shriver National Institute of Child Health and Human Development

  http://www.nichd.nih.gov/health/topics/pku/more_information/other-faqs

  If a child is diagnosed with PKU, other family members may be more likely to conceive children who also will have PKU. […] If you have PKU, it is very important to follow a strict low-phenylalanine diet before becoming pregnant and throughout your pregnancy. […] Infants and children with PKU need frequent blood tests to measure the phenylalanine in their blood. Their health care provider may suggest changes to the diet or formula the child receives if there is evidence of too much or too little phenylalanine.

• #2 Phenylketonuria: What Is It?

  https://www.webmd.com/digestive-disorders/phenylketonuria-overview

  PKU happens when there’s a problem with a gene that’s involved in the breakdown of Phe. […] Many countries, including the U.S., test newborns for PKU. It’s done through a simple blood test that happens a day or two after they’re born. A health care worker at the hospital usually takes the blood through a prick in your babys heel. Its put on a special paper and sent to a lab. Your babys doctor will share the results with you. […] The main way to treat PKU is with a low-protein diet. […] You should stay on treatment for life. If you go off the diet, you may have some memory loss, trouble concentrating, or you might feel anxious or depressed. If you stick with or go back on the diet, your mind will be sharper and youll feel better. […] You need to check the Phe levels in your blood often. This shows if your treatment is working. It also lowers the chance of brain, mood, and social problems. You usually check an infants levels once or twice a week by taking the blood sample from a tiny prick in the heel. In older kids and adults, you take the blood from a fingertip. You put the drop of blood on a card and mail it to a lab. If your level is off, your treatment team will work with you to bring it into a safe range.

• #2 The complete European guidelines on phenylketonuria: diagnosis and treatment | Orphanet Journal of Rare Diseases | Full Text

  https://ojrd.biomedcentral.com/articles/10.1186/s13023-017-0685-2

  The evidence regarding initiation of treatment with blood Phe concentrations between 360 and 600 mol/l is inconsistent. […] The evidence that supports treatment is of suboptimal quality. […] Since the introduction of NBS and early treatment, patients with PKU no longer develop profound and irreversible intellectual disability. […] The foremost question now is if patients should be treated throughout adulthood. […] As there is currently no strong evidence that it is safe to discontinue dietary treatment in adults, treatment for life is recommended. […] In PKU, life-long, systematic follow-up is recommended independent of the degree of adherence and (non-) treatment choice, to screen for long-term complications at any life stage, and provide appropriate support to patients. […] The primary goal of treatment is normal neurocognitive and psychosocial functioning.

• #2 Phenylketonuria (PKU)

  https://www2.hse.ie/conditions/heel-prick-screening/conditions/phenylketonuria-pku/

  Phenylketonuria (PKU) is a rare but potentially serious inherited disorder. […] About 1 in 4,500 babies born in Ireland has PKU. With early diagnosis and treatment most go on to live healthy lives. […] Babies can have heel prick screening at around 5 days old. This is to check if they have PKU or other conditions. […] If PKU is confirmed, treatment will be given straight away. This is to reduce the risk of complications. Treatment includes a special diet and regular blood tests. […] A child with PKU needs regular blood tests. This is to measure levels of phenylalanine and to see if they’re responding to treatment. […] In some cases, doctors may prescribe a medicine called sapropterin. This can help to break down phenylalanine so it will not build up in the blood. […] Women with PKU have to take special care during pregnancy. This is because high levels of phenylalanine can hurt an unborn baby. […] If phenylalanine levels are controlled problems can be avoided. Women with PKU are able to have normal, healthy babies.

• #2 Overview of phenylketonuria – UpToDate

  https://www.uptodate.com/contents/overview-of-phenylketonuria

  Phenylketonuria (PKU; MIM #261600) is a disorder affecting the aromatic amino acid, phenylalanine. It results from a deficiency of phenylalanine hydroxylase (PAH) and, if untreated, results in irreversible intellectual disability among other clinical symptoms. […] Most cases of PKU worldwide are caused by phenylalanine hydroxylase (PAH) deficiency. […] PKU is caused by deficiency of PAH. […] Complete enzyme deficiency results in classic PKU, in which serum phenylalanine plasma concentrations in an untreated, newly diagnosed newborn infant exceed 20 mg/dL (1200 micromol/L). Residual enzyme activity causes moderate PKU (phenylalanine concentrations 900 to 1200 micromol/L), mild PKU (phenylalanine concentrations 600 to 900 micromol/L), mild hyperphenylalaninemia (HPA; phenylalanine concentrations 360 to 600 micromol/L), and benign mild HPA that typically does not require treatment (phenylalanine concentrations 120 to 360 micromol/L).

• #2 Phenylketonuria (PKU)

  https://healthlibrary.inova.org/SummerHeat/167,pku

  Babies are often screened for PKU with a heel-prick test. […] The blood test may give a false-positive or false-negative result in certain cases: Your baby is premature or has liver problems. This could lead to a false-positive result because certain liver enzymes have not fully started working. […] Medicines, such as aspirin or antibiotics, may affect the results of the urine test for PKU.

• #2

  https://www.cdc.gov/mmwr/preview/mmwrhtml/00000243.htm

  Early diagnosis and treatment largely prevent the mental retardation associated with untreated PKU, and a properly executed program is clearly cost effective. […] Programs that reach every infant, perform the test reliably, provide timely follow-up of subjects with positive tests, assure accurate diagnosis, and provide appropriate counseling and treatment conform to published guidelines. […] Cases of PKU have been missed because the level of blood phenylalanine was not elevated above normal, even after the third day of life. […] In general, however, the chance of false-negative test results for PKU and other forms of PHP is greater when the blood sample is obtained before 72 hours of age. […] It is now firmly established that cord blood cannot be used for PKU/PHP screening. […] Accurate analysis of the sample is a critical facet of prevention. […] Infants with disorders of tetrahydrobiopterin homeostasis are likely to experience progressive neurologic deterioration when treated with low-phenylalanine diet alone.

• #2 Issues in Newborn Screening for Phenylketonuria | AAFP

  https://www.aafp.org/pubs/afp/issues/1999/1001/p1462.html

  When the initial newborn screening test and the second test show positive results, a confirmatory quantitative test, such as the McCamon-Robins fluorometric test, should be performed by a laboratory at a referral metabolic center. […] If a positive test is overlooked and the infant is subsequently found to have PKU, a malpractice lawsuit is almost certain to follow. […] If it becomes evident during regular follow-up of an infant that the infant’s development is delayed, it is useful to examine the report of PKU screening, and consideration may be given to repeating the test. […] With early diagnosis of PKU and institution of the phenylalanine-restricted diet, the prognosis for intellectual development in affected children is excellent.

• #2 Phenylketonuria (PKU)

  https://healthlibrary.uwmedicine.org/Library/PreventionGuidelines/167,pku

  The blood test may give a false-positive or false-negative result in certain cases: Your baby is premature or has liver problems. This could lead to a false-positive result because certain liver enzymes have not fully started working. […] Your baby has feeding problems, such as vomiting. This could give a false-negative result. […] Medicines, such as aspirin or antibiotics, may affect the results of the urine test for PKU.

• #2 Newborn screening information for classic phenylketonuria | Baby’s First Test | Newborn Screening | Baby Health

  https://www.babysfirsttest.org/newborn-screening/conditions/classic-phenylketonuria-pku

  If phenylketonuria (PKU) is detected at birth, early treatment can prevent the signs of the condition mentioned in the Early Signs section. […] If treatment is started after six months of age, babies are at risk for severe intellectual disabilities. […] It is important to treat PKU, even if treatment is started after noticing signs and symptoms, in order to help prevent permanent brain damage. […] PKU is an autosomal recessive genetic condition. This means that a child must inherit two copies of the non-working gene for PKU, one from each parent, in order to have the condition.

• #2 Phenylketonuria (PKU) | Texas DSHS

  https://www.dshs.texas.gov/newborn-screening-program/newborn-screening-parent-resources/phenylketonuria-pku

  Phenylketonuria (PKU) is a condition some children have that affects their ability to properly use protein from their food. […] Severe intellectual disabilities and other problems resulting from PKU can be prevented by early diagnosis and proper diet control. […] PKU cannot be cured but can be treated if a special diet is started early in the newborn period. Current research indicates that the special diet should be continued at least through adolescence and possibly throughout life. […] The Texas Department of State Health Services provides, without charge to residents of Texas who are diagnosed with PKU, blood specimen analysis through the Texas Department of State Health Services Laboratory in Austin.

• #2

• #2 Phenylketonuria – Symptoms, diagnosis and treatment | BMJ Best Practice US

  https://bestpractice.bmj.com/topics/en-us/867

  Phenylketonuria (PKU) is diagnosed by newborn screening and managed by a multidisciplinary team of specialists. […] Key diagnostic factors include family history of PKU and positive newborn screen for PKU. […] The first tests to order include newborn screening for metabolic disorders. […] Tests to consider include quantitative plasma amino acid analysis, blood dihydropteridine reductase (DHPR) assay, urine neopterin to biopterin ratio, mutation analysis of phenylalanine hydroxylase gene, and tetrahydrobiopterin (BH4)-responsiveness test.

• #2 Newborn Screening Program – Phenylketonuria

  http://www.idph.state.il.us/healthwellness/fs/pku.htm

  The National Institutes of Health recommends lifetime low phenylalanine diet for individuals with PKU. […] PKU and hyperphenylalaninemia occur in one of every 12,000 births. […] These disorders are inherited in an autosomal recessive pattern. […] Classical PKU is due to a deficiency of the liver enzyme, phenylalanine hydroxylase. […] Parents should understand that treatment is lifelong and that compliance with dietary management is imperative to the child’s health, growth and development. […] Infants and children with PKU or hyperphenylalaninemia should have regular follow-up appointments with a metabolic disease specialist. […] With proper medical care and lifelong dietary management, children with PKU can enjoy healthy, productive lives.

• #3 PKU Test for Phenylketonuria: Purpose, Procedure, Results

  https://www.webmd.com/children/pku-test

  Your newborn seems perfect. They’ve got 10 fingers and toes and a hearty appetite. But even healthy-looking babies can have problems you cant see. A simple blood test looks for rare conditions, including phenylketonuria (PKU), which can harm your babys growing brain. […] Every baby in the United States is tested for PKU as part of newborn screenings that check for many other conditions, too. […] The test measures the amount of Phe in your babys blood. […] A normal level is less than 2 milligrams per deciliter (mg/dL). More than 4 mg/dL is considered high. Even if your babys results arent in that range, it doesnt necessarily mean they have PKU. It means they need more tests to find out for sure. […] If PKU isnt diagnosed and treated right away, it can cause lasting problems, including developmental delays, lower IQ, mood disorders, hyperactivity, and severe intellectual disability.

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