Materiały źródłowe

• #1 Understanding Albinism: Causes, Symptoms And Types

  https://www.ajhospital.in/news/understanding-albinism-causes-symptoms-and-types

  Albinism is primarily a genetic condition caused by inherited mutations in specific genes. These genetic mutations disrupt the production, transportation, or storage of melanin in the body. The most common types of albinism, known as oculocutaneous albinism (OCA), are caused by mutations in genes such as OCA1, OCA2, OCA3, and OCA4. Each gene mutation has a unique impact on melanin production, leading to variations in the severity of albinism’s characteristics. […] Albinism is caused by inheriting mutations in specific genes that disrupt the production, transportation, or storage of melanin in the body. […] Albinism is a condition that encompasses various types, each characterised by distinct genetic mutations and unique phenotypic presentations. The most common form is known as oculocutaneous albinism (OCA), which further branches into subtypes based on specific gene mutations.

• #2 Albinism: What It Is, Symptoms, Types & Causes | Bajaj Allianz

  https://www.bajajallianz.com/blog/wellness/understanding-albinism-causes-types-and-signs.html

  Causes of albinism revolve around genetic mutations that affect melanin production. Melanin is synthesised by specialised cells known as melanocytes, and any disruption in this process leads to albinism. The primary genetic causes include: […] Mutations in the TYR gene: A defect in the tyrosinase enzyme, which is crucial for melanin production. […] OCA2 gene defects: These affect melanin synthesis and distribution. […] Other genetic mutations: Additional genes like TYRP1, SLC45A2, and GPR143 also play roles in different types of albinism. […] For albinism to manifest, a child must inherit the defective gene from both parents, making it an autosomal recessive condition.

• #3 Albinism – Symptoms and causes – Mayo Clinic

  https://www.mayoclinic.org/diseases-conditions/albinism/symptoms-causes/syc-20369184

  Albinism is caused by a change in one of these genes. Different types of albinism can occur, based mainly on which gene change caused the disorder. The gene change may result in no melanin at all or a big decrease in the amount of melanin. […] Several genes give instructions for making one of several proteins involved in producing melanin. Melanin is made by cells called melanocytes that are found in your skin, hair and eyes. […] Oculocutaneous albinism (OCA), the most common type, means a person gets two copies of a changed gene one from each parent. This is called autosomal recessive inheritance. OCA is the result of a change in one of eight genes, labeled from OCA1 to OCA8. OCA causes decreased pigment in the skin, hair and eyes, as well as vision problems. The amount of pigment varies by type. The resulting color of skin, hair and eyes also varies by and within types.

• #4 Albinism – StatPearls – NCBI Bookshelf

  https://www.ncbi.nlm.nih.gov/books/NBK519018/

  Albinism, in any of its forms, is the result of heritable mutations that lead to defective melanocytes, unable to properly synthesize melanin or distribute it through dermal tissues. […] The specific gene mutations causing each form or albinism are mentioned below in the „History and Physical” section. […] To date, seven types of nonsyndromic albinism (OCA1 to OCA7) have been described. These are all due to isolated genetic mutations whose constellation of signs and symptoms do not manifest so broadly that they can be classified as syndromic. […] The genetic aberrations specific to each form of OCA, syndromic albinisms, and selected albinism-associated disorders are included below: […] OCA1: Autosomal recessive. The TYR gene product tyrosinase normally hydroxylates L-tyrosine to L-DOPA and oxidates L-DOPA to DOPAquinone. This serves as the rate-limiting/ step in melanin synthesis. Loss of this function leads to an inability to synthesize melanin.

• #5 Albinism – Symptoms and causes – Mayo Clinic

  https://www.mayoclinic.org/diseases-conditions/albinism/symptoms-causes/syc-20369184

  Autosomal recessive inheritance pattern. To have an autosomal recessive disorder, you inherit two changed genes, sometimes called mutations. You get one from each parent. Their health is rarely affected because they have only one changed gene. Two carriers have a 25% chance of having an unaffected child with two unaffected genes. They have a 50% chance of having an unaffected child who also is a carrier. They have a 25% chance of having an affected child with two changed genes.

• #6 Albinism (for Teens) | Nemours KidsHealth

  https://kidshealth.org/en/teens/albinism.html

  Albinism is an inherited condition that leads to someone having very light skin, hair, and eyes. It happens because they have less melanin than usual in their body. […] Most of the time, someone has albinism because they inherited the gene for it from both their mother and father. Having just one of the genes (being a carrier”) does not give you albinism. […] Sometimes, albinism is caused by a new gene change (called a mutation).

• #7 Albinism

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

  Albinism is passed on in an autosomal recessive inheritance pattern. This means a child has to get 2 copies of the gene that causes albinism (1 from each parent) to have the condition. […] Most types of OA are passed on in an X-linked inheritance pattern. This pattern affects boys and girls differently: girls who get the albinism gene usually become carriers only, while boys who get it will have albinism.

• #8 Albinism: What it is, types, symptoms, treatment, and is it genetic

  https://www.medicalnewstoday.com/articles/245861

  Albinism is an inherited condition in which the body produces little or no melanin, the pigment that gives color to the skin and hair. […] Albinism is a genetic condition. […] An estimated 1 in 70 people carry the genetic mutation associated with albinism. […] Specialized cells in the skin, hair, and eyes called melanocytes produce melanin. If there is a change in one of these genes, it can cause albinism. […] Most commonly, the mutations interfere with an enzyme called tyrosinase. This enzyme breaks down the amino acid tyrosine and creates melanin. […] Depending on the specific mutation, melanin production either slows down or stops entirely. […] Yes, albinism is genetic. Most types of albinism have what doctors call an autosomal recessive inheritance pattern. […] With autosomal recessive inheritance, an individual must receive mutated copies of a gene from both the mother and father to develop albinism.

• #9 Albinism: What it is, types, symptoms, treatment, and is it genetic

  https://www.medicalnewstoday.com/articles/245861

  Albinism is an inherited condition in which the body produces little or no melanin, the pigment that gives color to the skin and hair. […] Albinism is a genetic condition. […] An estimated 1 in 70 people carry the genetic mutation associated with albinism. […] Specialized cells in the skin, hair, and eyes called melanocytes produce melanin. If there is a change in one of these genes, it can cause albinism. […] Most commonly, the mutations interfere with an enzyme called tyrosinase. This enzyme breaks down the amino acid tyrosine and creates melanin. […] Depending on the specific mutation, melanin production either slows down or stops entirely. […] Yes, albinism is genetic. Most types of albinism have what doctors call an autosomal recessive inheritance pattern. […] With autosomal recessive inheritance, an individual must receive mutated copies of a gene from both the mother and father to develop albinism.

• #10

  https://dermnetnz.org/topics/albinism

  Albinism is mostly a recessively inherited disease, which means two albinism genes are inherited (one from each parent). […] About 1 in 70 people have a gene for albinism. Couples whom are each carriers of the recessive albinism gene have a 1 in 4 chance of producing a child with albinism. […] The main problems of albinism are caused by the inability of the body to produce melanin pigment (whose major role in the skin is to absorb UV light from the sun so skin is not sun-damaged).

• #11 Oculocutaneous albinism – UpToDate

  https://www.uptodate.com/contents/oculocutaneous-albinism

  Oculocutaneous albinism (OCA) is a group of rare genetic disorders of melanin biosynthesis that disrupt melanosomal proteins; each is inherited in an autosomal recessive pattern. Eight types of OCA caused by variants in different genes have been recognized. All types share reduced to absent pigmentation of skin, hair, and eyes, but the clinical phenotypes vary along a broad spectrum of disease severity. […] The ocular manifestations, including reduced vision, photophobia, nystagmus, and strabismus, are the most debilitating aspect of OCA. They are associated with a reduction in melanin within the iris and retina and misrouting of the optic nerve fibers from the eye to the brain during development. […] The overall prevalence of albinism in the Western world is estimated to be 1 in 17,000 to 1 in 20,000, with ample variations across ethnic groups and geographic regions. One in 70 individuals is estimated to carry an OCA-mutated allele.

• #12

  https://www.oxfordbiolabs.com/blogs/news/albinism-genetics-causes-and-symptoms

  In North America and Europe, albinism affects 1 in 20,000 people, and in some places in Africa, 1 in 5,000 suffer from this hereditary condition. […] Albinism is a rare, genetic disorder that causes partial or complete lack of pigmentation (melanin) in the skin, hair and eyes. This results in a vulnerability to sunlight, which may lead to sunburn and sometimes skin cancer. It affects people from all around the world regardless of race, ethnicity, or gender. Its caused by a recessive gene, meaning that usually both parents are carriers and pass the gene to their children. Genetic mutations inhibit the production of pigment in melanocytes, the cells responsible for pigmentation. […] There is not a way to counter-act albinism. Quality of life can be improved with lifestyle changes like wearing sunscreen, sunglasses, and clothing that covers the skin. Visual aids, prescription glasses or contact lenses, and surgery can help, along with other coping skills. Prevention through genetic testing prior to childbirth is not a viable, cost-effective option, unless a family member or relative has albinism. In these cases a geneticist can assess the chances of having children with albinism.

• #13 Albinism and Human Eyes: How Does Albinism Affect Vision?

  https://www.allaboutvision.com/conditions/related/how-albinism-affects-vision/

  An estimated one in 18,000 to 20,000 people in the U.S. has some type of albinism. While albinism is generally rare, some forms of the condition are extremely rare. All types can affect a person’s vision. […] The most common form, oculocutaneous albinism (OCA), occurs when the tyrosinase (TYR) gene mutates, resulting in a person having an absence or reduced amount of melanin (color-providing pigment). […] Ocular albinism (OA) is the other main form of albinism. Unlike OCA, it only affects the eyes. It is also much less common than OCA, affecting only around one in 60,000 males and even fewer females. Ocular albinism affects only the eyes, not the skin or hair. Ocular albinism reduces coloring in the iris and affects proper development of the retina. […] People with OA may have light sensitivity, nystagmus, strabismus and depth perception issues. Their visual acuity is typically lower than normal, ranging from 20/60 to 20/400.

• #14 Oculocutaneous Albinism and Ocular Albinism Overview – GeneReviews® – NCBI Bookshelf

  https://www.ncbi.nlm.nih.gov/books/NBK590568/

  Albinism is a genetically heterogeneous hypopigmentary disorder characterized by cutaneous and ocular hypopigmentation. […] Review the genetic causes of oculocutaneous albinism and ocular albinism. […] Table 2 summarizes genes known to be associated with nonsyndromic OCA and OA. All nonsyndromic OCA is inherited in an autosomal recessive manner. OA (which is always nonsyndromic) is inherited in an X-linked manner. […] Nonsyndromic oculocutaneous albinism (OCA) caused by pathogenic variants in TYR, OCA2, TYRP1, SLC45A2, SLC24A5, LRMDA (C10orf11), or DCT (TYRP2) is inherited in an autosomal recessive manner. Ocular albinism (OA) caused by pathogenic variants in GPR143 (OA1) is inherited in an X-linked manner.

• #15 Azthena logo with the word Azthena

  https://www.news-medical.net/health/Albinism-Causes.aspx

  Albinism is a condition wherein the human body does not produce enough of the pigment melanin. In some cases, there may be absolutely no melanin produced. The lack of melanin results in a discoloration of the skin, hair and iris of the eye. […] It is caused by a genetic defect. […] There are primarily two kinds of albinism, oculocutaneous albinism or OCA and ocular albinism or OA. Both are caused by different types of genetic mutation passed from the parent to the child. […] With OCA, however, if each parent has one normal pigment gene (carrier), 25% of the children will be clinically affected but 50% of children may be carriers of the albinism gene, while 25% have a chance of being born with clinical albinism. […] Some types of OA generally affect male children. They inherit the defective gene from their mothers in what is termed as X-linked inheritance.

• #16 Information Bulletin – What is Albinism? – National Organization for Albinism and Hypopigmentation

  https://albinism.org/information-bulletin-what-is-albinism/

  Albinism is an inherited genetic condition that reduces the amount of melanin pigment formed in the skin, hair and/or eyes. […] The presence of these eye problems defines the diagnosis of albinism. […] DNA tests can determine the precise type of albinism. Research on albinism genes is ongoing. To date as many as seven forms of oculocutaneous albinism are now recognized OCA1, OCA2, OCA3, OCA4, OCA5, OCA6 and OCA7. […] OCA1, or tyrosinase-related albinism, results from a genetic defect in an enzyme called tyrosinase. This enzyme helps the body to change the amino acid, tyrosine, into pigment. […] OCA2, or P gene albinism, results from a genetic defect in the P protein that helps the tyrosinase enzyme to function. […] OCA3 is rarely described and results from a genetic defect in TYRP1, a protein related to tyrosinase.

• #17 Albinism – Dermatologic Disorders – Merck Manual Professional Edition

  https://www.merckmanuals.com/professional/dermatologic-disorders/pigmentation-disorders/albinism

  Oculocutaneous albinism is an inherited defect in melanin formation that causes diffuse hypopigmentation of the skin, hair, and eyes. […] Oculocutaneous albinism (OCA) is a group of rare inherited disorders in which a normal number of melanocytes are present but melanin production is absent or greatly decreased. […] Most cases of OCA are autosomal recessive; autosomal dominant inheritance is rare. […] There are 8 genetic forms of OCA, of which the first 4 are well characterized. […] Mutations in TYR gene result in absent (OCA1A) or reduced (OCA1B) tyrosinase activity. […] Tyrosinase catalyzes several steps in melanin synthesis. […] In OCA type II, the function of the P protein is not yet known but may involve regulation of organelle pH and accumulation of vacuolar glutathione. […] This gene encodes a membrane transporter protein involved in tyrosinase processing and trafficking of proteins to melanosomes.

• #18 Albinism – StatPearls – NCBI Bookshelf

  https://www.ncbi.nlm.nih.gov/books/NBK519018/

  Albinism, in any of its forms, is the result of heritable mutations that lead to defective melanocytes, unable to properly synthesize melanin or distribute it through dermal tissues. […] The specific gene mutations causing each form or albinism are mentioned below in the „History and Physical” section. […] To date, seven types of nonsyndromic albinism (OCA1 to OCA7) have been described. These are all due to isolated genetic mutations whose constellation of signs and symptoms do not manifest so broadly that they can be classified as syndromic. […] The genetic aberrations specific to each form of OCA, syndromic albinisms, and selected albinism-associated disorders are included below: […] OCA1: Autosomal recessive. The TYR gene product tyrosinase normally hydroxylates L-tyrosine to L-DOPA and oxidates L-DOPA to DOPAquinone. This serves as the rate-limiting/ step in melanin synthesis. Loss of this function leads to an inability to synthesize melanin.

• #19 Albinism – Dermatologic Disorders – Merck Manual Professional Edition

  https://www.merckmanuals.com/professional/dermatologic-disorders/pigmentation-disorders/albinism

  Oculocutaneous albinism is an inherited defect in melanin formation that causes diffuse hypopigmentation of the skin, hair, and eyes. […] Oculocutaneous albinism (OCA) is a group of rare inherited disorders in which a normal number of melanocytes are present but melanin production is absent or greatly decreased. […] Most cases of OCA are autosomal recessive; autosomal dominant inheritance is rare. […] There are 8 genetic forms of OCA, of which the first 4 are well characterized. […] Mutations in TYR gene result in absent (OCA1A) or reduced (OCA1B) tyrosinase activity. […] Tyrosinase catalyzes several steps in melanin synthesis. […] In OCA type II, the function of the P protein is not yet known but may involve regulation of organelle pH and accumulation of vacuolar glutathione. […] This gene encodes a membrane transporter protein involved in tyrosinase processing and trafficking of proteins to melanosomes.

• #20 Albinism – StatPearls – NCBI Bookshelf

  https://www.ncbi.nlm.nih.gov/books/NBK519018/

  OCA2: Autosomal recessive. The OCA2 gene product is the OCA2 melanosome transmembrane protein P, with unknown function. […] OCA3: Autosomal recessive. The TYRP1 gene product is tyrosinase-related protein 1, which is thought to stabilize and modulate the activity of tyrosinase and contribute to melanosome integrity. […] OCA4: Autosomal recessive. The SLC45A2 gene codes for a solute carrier family 45, member 2 membrane-associated transport protein (MATP) that is thought to transport substances required for melanin biosynthesis into the melanosome. […] OCA5: Autosomal recessive. Gene not yet identified. […] OCA6: Autosomal recessive. The SLC24A5 gene (solute carrier family 24, member 5) codes for a Na/K/Ca cation exchange protein with a similar structure to that seen in OCA4. Its function is also thought to be similar.

• #21 Albinism: Causes, Types, Pictures, Symptoms, and More

  https://www.healthline.com/health/albinism

  OCA2, or oculocutaneous type 2, is a more common type of albinism caused by genetic mutation. OCA2 comes from mutation in the P gene, which is also associated with other rare genetic disorders such as Prader-Willi syndrome. […] OCA3 is the result of a defect in the TYRP1 gene. […] OCA4 is caused by a defect in the SLC45A2 protein. […] Hermansky-Pudlak syndrome is a rare form of albinism that’s caused by a defect in one of 10 genes. […] Chediak-Higashi syndrome is another rare form of albinism that’s the result of a defect in the LYST gene. […] Griscelli syndrome is an extremely rare genetic disorder. It’s caused by a defect in one of three genes.

• #22 Albinism – StatPearls – NCBI Bookshelf

  https://www.ncbi.nlm.nih.gov/books/NBK519018/

  OCA2: Autosomal recessive. The OCA2 gene product is the OCA2 melanosome transmembrane protein P, with unknown function. […] OCA3: Autosomal recessive. The TYRP1 gene product is tyrosinase-related protein 1, which is thought to stabilize and modulate the activity of tyrosinase and contribute to melanosome integrity. […] OCA4: Autosomal recessive. The SLC45A2 gene codes for a solute carrier family 45, member 2 membrane-associated transport protein (MATP) that is thought to transport substances required for melanin biosynthesis into the melanosome. […] OCA5: Autosomal recessive. Gene not yet identified. […] OCA6: Autosomal recessive. The SLC24A5 gene (solute carrier family 24, member 5) codes for a Na/K/Ca cation exchange protein with a similar structure to that seen in OCA4. Its function is also thought to be similar.

• #23 What causes albinism (albinos)? – Calcium Zone

  https://archive.imascientist.org.uk/calciumj11-zone/question/what-causes-albinism-albinos.html

  Albinism is a disease in which a person has partial or complete loss of pigmentation (colouring) of the skin, eyes and hair. […] It involves the production of a pigment called melanin. There is a cell called the melanocyte that is responsible for giving skin, hair, and eyes pigmentation. In albinism, the melanocytes are present, but genetic mutations interfere with their pigment production or their ability to distribute it to keratinocytes. […] There are currently five known genetic types of albinism, the most common being oculocutaneous type 1 (OCA1) and type 2 (OCA2). […] Patients with OCA1 have mutations in a gene called TYR that is responsible for creating the enzyme tyrosinase, used by cells to convert the amino acid tyrosine into pigment molecules that colour the skin, hair, and eyes. OCA2, the most common form of albinism in Africa, results from a mutation in the OCA2 gene, which encodes the P protein.

• #24 Albinism – StatPearls – NCBI Bookshelf

  https://www.ncbi.nlm.nih.gov/books/NBK519018/

  OCA2: Autosomal recessive. The OCA2 gene product is the OCA2 melanosome transmembrane protein P, with unknown function. […] OCA3: Autosomal recessive. The TYRP1 gene product is tyrosinase-related protein 1, which is thought to stabilize and modulate the activity of tyrosinase and contribute to melanosome integrity. […] OCA4: Autosomal recessive. The SLC45A2 gene codes for a solute carrier family 45, member 2 membrane-associated transport protein (MATP) that is thought to transport substances required for melanin biosynthesis into the melanosome. […] OCA5: Autosomal recessive. Gene not yet identified. […] OCA6: Autosomal recessive. The SLC24A5 gene (solute carrier family 24, member 5) codes for a Na/K/Ca cation exchange protein with a similar structure to that seen in OCA4. Its function is also thought to be similar.

• #25 Albinism: Causes, Types, Pictures, Symptoms, and More

  https://www.healthline.com/health/albinism

  OCA2, or oculocutaneous type 2, is a more common type of albinism caused by genetic mutation. OCA2 comes from mutation in the P gene, which is also associated with other rare genetic disorders such as Prader-Willi syndrome. […] OCA3 is the result of a defect in the TYRP1 gene. […] OCA4 is caused by a defect in the SLC45A2 protein. […] Hermansky-Pudlak syndrome is a rare form of albinism that’s caused by a defect in one of 10 genes. […] Chediak-Higashi syndrome is another rare form of albinism that’s the result of a defect in the LYST gene. […] Griscelli syndrome is an extremely rare genetic disorder. It’s caused by a defect in one of three genes.

• #26 Albinism – StatPearls – NCBI Bookshelf

  https://www.ncbi.nlm.nih.gov/books/NBK519018/

  OCA2: Autosomal recessive. The OCA2 gene product is the OCA2 melanosome transmembrane protein P, with unknown function. […] OCA3: Autosomal recessive. The TYRP1 gene product is tyrosinase-related protein 1, which is thought to stabilize and modulate the activity of tyrosinase and contribute to melanosome integrity. […] OCA4: Autosomal recessive. The SLC45A2 gene codes for a solute carrier family 45, member 2 membrane-associated transport protein (MATP) that is thought to transport substances required for melanin biosynthesis into the melanosome. […] OCA5: Autosomal recessive. Gene not yet identified. […] OCA6: Autosomal recessive. The SLC24A5 gene (solute carrier family 24, member 5) codes for a Na/K/Ca cation exchange protein with a similar structure to that seen in OCA4. Its function is also thought to be similar.

• #27 Albinism – StatPearls – NCBI Bookshelf

  https://www.ncbi.nlm.nih.gov/books/NBK519018/

  OCA2: Autosomal recessive. The OCA2 gene product is the OCA2 melanosome transmembrane protein P, with unknown function. […] OCA3: Autosomal recessive. The TYRP1 gene product is tyrosinase-related protein 1, which is thought to stabilize and modulate the activity of tyrosinase and contribute to melanosome integrity. […] OCA4: Autosomal recessive. The SLC45A2 gene codes for a solute carrier family 45, member 2 membrane-associated transport protein (MATP) that is thought to transport substances required for melanin biosynthesis into the melanosome. […] OCA5: Autosomal recessive. Gene not yet identified. […] OCA6: Autosomal recessive. The SLC24A5 gene (solute carrier family 24, member 5) codes for a Na/K/Ca cation exchange protein with a similar structure to that seen in OCA4. Its function is also thought to be similar.

• #28 Albinism – StatPearls – NCBI Bookshelf

  https://www.ncbi.nlm.nih.gov/books/NBK519018/

  OCA7: Autosomal recessive. The LRMDA gene (leucine-rich melanocyte differentiation associated protein) codes for a protein thought to play a role in melanocyte differentiation. […] Hermansky-Pudlak syndrome (HPS): Autosomal recessive. Ten different genotypes have been identified, thus far. […] Chediak-Higashi syndrome (CHS): Autosomal recessive. The LYST gene codes for a protein that directs delivery of material into lysosomes. […] Angelman syndrome (AS) and Prader-Willi syndrome (PWS): Both due to spontaneous (not inherited) partial deletions of chromosome 15q. Albinism occurs because the OCA2 allele located on one Chromosome 15q, making subjects haploinsufficient for OCA2 gene product, protein P. […] Ocular albinism (OA1): X-linked. The GPR143 gene product is a G-protein coupled receptor, a mutation in which yields dysfunctional melanosome biogenesis with resultant „macromelanosomes.”

• #29 Oculocutaneous Albinism and Ocular Albinism Overview – GeneReviews® – NCBI Bookshelf

  https://www.ncbi.nlm.nih.gov/books/NBK590568/

  Albinism is a genetically heterogeneous hypopigmentary disorder characterized by cutaneous and ocular hypopigmentation. […] Review the genetic causes of oculocutaneous albinism and ocular albinism. […] Table 2 summarizes genes known to be associated with nonsyndromic OCA and OA. All nonsyndromic OCA is inherited in an autosomal recessive manner. OA (which is always nonsyndromic) is inherited in an X-linked manner. […] Nonsyndromic oculocutaneous albinism (OCA) caused by pathogenic variants in TYR, OCA2, TYRP1, SLC45A2, SLC24A5, LRMDA (C10orf11), or DCT (TYRP2) is inherited in an autosomal recessive manner. Ocular albinism (OA) caused by pathogenic variants in GPR143 (OA1) is inherited in an X-linked manner.

• #30 Albinism vs. Vitiligo: What’s the Difference? | MyVitiligoTeam

  https://www.myvitiligoteam.com/resources/albinism-vs-vitiligo-whats-the-difference

  The only risk factor for albinism is having relatives who have had it, which indicates the presence of those mutated genes in the family tree. […] There are several types of albinism. Oculocutaneous albinism (OCA) is the most common type. OCA occurs when a person has inherited two mutated copies of one of seven OCA genes one from their mother and one from their father. […] Ocular albinism primarily affects the eyes, and the skin may appear similar or slightly lighter than other family members’ skin. […] Partial albinism is extremely rare. It occurs when there are mutations in one particular gene known as the KIT gene.

• #31 Albinism: Types, Symptoms & Causes

  https://my.clevelandclinic.org/health/diseases/21747-albinism

  Albinism is a rare genetic condition caused by mutations, or changes, of certain genes that affect the amount of melanin your body produces. […] Variations in the genes responsible for melanin production cause albinism. Specific genes associated with oculocutaneous albinism include: TYR, OCA2, TYRP1, SLC45A2. […] Some people with albinism don’t have variations in any of these genes. In these cases, the exact genetic cause is unknown. […] Yes, albinism is passed down (inherited) through families. […] Oculocutaneous albinism (OCA) follows an autosomal recessive pattern of inheritance. […] Ocular albinism (OA) usually follows an X-linked pattern of inheritance. […] Albinism isn’t a disease. Albinism is a genetic condition that people are born with. It’s not contagious and it can’t be spread.

• #32 Albinism

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

  Albinism is passed on in an autosomal recessive inheritance pattern. This means a child has to get 2 copies of the gene that causes albinism (1 from each parent) to have the condition. […] Most types of OA are passed on in an X-linked inheritance pattern. This pattern affects boys and girls differently: girls who get the albinism gene usually become carriers only, while boys who get it will have albinism.

• #33 Albinism – StatPearls – NCBI Bookshelf

  https://www.ncbi.nlm.nih.gov/books/NBK519018/

  OCA7: Autosomal recessive. The LRMDA gene (leucine-rich melanocyte differentiation associated protein) codes for a protein thought to play a role in melanocyte differentiation. […] Hermansky-Pudlak syndrome (HPS): Autosomal recessive. Ten different genotypes have been identified, thus far. […] Chediak-Higashi syndrome (CHS): Autosomal recessive. The LYST gene codes for a protein that directs delivery of material into lysosomes. […] Angelman syndrome (AS) and Prader-Willi syndrome (PWS): Both due to spontaneous (not inherited) partial deletions of chromosome 15q. Albinism occurs because the OCA2 allele located on one Chromosome 15q, making subjects haploinsufficient for OCA2 gene product, protein P. […] Ocular albinism (OA1): X-linked. The GPR143 gene product is a G-protein coupled receptor, a mutation in which yields dysfunctional melanosome biogenesis with resultant „macromelanosomes.”

• #34 Poor Eyesight From Albinism? Our Eye Doctors Are Here to Help!

  https://ialvs.com/ways-we-can-help/what-is-a-low-vision-exam/low-vision-eye-diseases/albinism-and-eyesight/

  Albinism is a genetic disorder that results in the body’s inability to produce melanin, a dark pigment that protects our tissues from ultraviolet radiation (UV) and gives the eyes, skin, and hair their color. […] Ocular albinism primarily affects the eyes, by reducing the coloring (pigmentation) in the eye, which is essential for normal vision. […] Ocular albinism causes mild to moderate central vision impairment in most patients. […] The most common form of ocular albinism is Type 1 or Nettleship-Falls. […] Women are the carriers of the gene mutations that cause the disorder. […] Ocular albinism causes a reduction in the coloring, or pigmentation, of the iris, the colored part of the eye, and the retina, the light-sensitive tissue located at the back of the eye. […] While most people with ocular albinism have light blue eyes, in some cases the blood vessels within the eyeball can become visible through the iris, leading the eyes to appear red or pink.

• #35 Albinism – StatPearls – NCBI Bookshelf

  https://www.ncbi.nlm.nih.gov/books/NBK519018/

  OCA7: Autosomal recessive. The LRMDA gene (leucine-rich melanocyte differentiation associated protein) codes for a protein thought to play a role in melanocyte differentiation. […] Hermansky-Pudlak syndrome (HPS): Autosomal recessive. Ten different genotypes have been identified, thus far. […] Chediak-Higashi syndrome (CHS): Autosomal recessive. The LYST gene codes for a protein that directs delivery of material into lysosomes. […] Angelman syndrome (AS) and Prader-Willi syndrome (PWS): Both due to spontaneous (not inherited) partial deletions of chromosome 15q. Albinism occurs because the OCA2 allele located on one Chromosome 15q, making subjects haploinsufficient for OCA2 gene product, protein P. […] Ocular albinism (OA1): X-linked. The GPR143 gene product is a G-protein coupled receptor, a mutation in which yields dysfunctional melanosome biogenesis with resultant „macromelanosomes.”

• #36 Albinism

  https://aapos.org/glossary/albinism

  Some people with albinism can have rare medical problems that affect the rest of the body. There are two main medical problems that can be seen in people with albinism. Hermansky Pudlak Syndrome (HPS) can cause bleeding problems and bruising. Some types of HPS also have lung and bowel/gut problems. HPS is a less common form of albinism but should be checked for if a person with albinism shows unusual bruising or bleeding. Chdiak-Higashi syndrome affects parts of the body. The disease can cause higher risk of infections, anemia (low blood count), and hepatomegaly (enlarged liver). While these problems are rare, they can happen in some people with albinism and may need special testing and care.

• #37 Albinism – StatPearls – NCBI Bookshelf

  https://www.ncbi.nlm.nih.gov/books/NBK519018/

  OCA7: Autosomal recessive. The LRMDA gene (leucine-rich melanocyte differentiation associated protein) codes for a protein thought to play a role in melanocyte differentiation. […] Hermansky-Pudlak syndrome (HPS): Autosomal recessive. Ten different genotypes have been identified, thus far. […] Chediak-Higashi syndrome (CHS): Autosomal recessive. The LYST gene codes for a protein that directs delivery of material into lysosomes. […] Angelman syndrome (AS) and Prader-Willi syndrome (PWS): Both due to spontaneous (not inherited) partial deletions of chromosome 15q. Albinism occurs because the OCA2 allele located on one Chromosome 15q, making subjects haploinsufficient for OCA2 gene product, protein P. […] Ocular albinism (OA1): X-linked. The GPR143 gene product is a G-protein coupled receptor, a mutation in which yields dysfunctional melanosome biogenesis with resultant „macromelanosomes.”

• #38 Albinism: Symptoms, Causes, Diagnosis & Treatment

  https://www.webmd.com/skin-problems-and-treatments/what-is-albinism

  Faulty genes passed down from your parents prevent your body from making enough melanin. Different types of albinism stem from defects in different enzymes and proteins in your DNA. […] Albinism also can be linked to a few rare conditions caused by a problem with your genes: Hermansky-Pudlak syndrome. This is a rare form of albinism that also causes easy bruising and bleeding. Chediak-Higashi syndrome. Another rare form of albinism, this can cause a low red blood cell count (anemia) and an enlarged liver and can make you more likely to get infections. Griscelli syndrome type 2. Also called partial albinism and immunodeficiency syndrome, this is a rare condition that’s caused by a faulty gene. Symptoms include light skin, silver hair, and serious problems with your immune system that can eventually damage organs and tissues.

• #39 Albinism – StatPearls – NCBI Bookshelf

  https://www.ncbi.nlm.nih.gov/books/NBK519018/

  OCA7: Autosomal recessive. The LRMDA gene (leucine-rich melanocyte differentiation associated protein) codes for a protein thought to play a role in melanocyte differentiation. […] Hermansky-Pudlak syndrome (HPS): Autosomal recessive. Ten different genotypes have been identified, thus far. […] Chediak-Higashi syndrome (CHS): Autosomal recessive. The LYST gene codes for a protein that directs delivery of material into lysosomes. […] Angelman syndrome (AS) and Prader-Willi syndrome (PWS): Both due to spontaneous (not inherited) partial deletions of chromosome 15q. Albinism occurs because the OCA2 allele located on one Chromosome 15q, making subjects haploinsufficient for OCA2 gene product, protein P. […] Ocular albinism (OA1): X-linked. The GPR143 gene product is a G-protein coupled receptor, a mutation in which yields dysfunctional melanosome biogenesis with resultant „macromelanosomes.”

• #40 Albinism: Symptoms, Causes, Diagnosis & Treatment

  https://www.webmd.com/skin-problems-and-treatments/what-is-albinism

  Faulty genes passed down from your parents prevent your body from making enough melanin. Different types of albinism stem from defects in different enzymes and proteins in your DNA. […] Albinism also can be linked to a few rare conditions caused by a problem with your genes: Hermansky-Pudlak syndrome. This is a rare form of albinism that also causes easy bruising and bleeding. Chediak-Higashi syndrome. Another rare form of albinism, this can cause a low red blood cell count (anemia) and an enlarged liver and can make you more likely to get infections. Griscelli syndrome type 2. Also called partial albinism and immunodeficiency syndrome, this is a rare condition that’s caused by a faulty gene. Symptoms include light skin, silver hair, and serious problems with your immune system that can eventually damage organs and tissues.

• #41 Albinism: Symptoms, Causes, Diagnosis & Treatment

  https://www.webmd.com/skin-problems-and-treatments/what-is-albinism

  Faulty genes passed down from your parents prevent your body from making enough melanin. Different types of albinism stem from defects in different enzymes and proteins in your DNA. […] Albinism also can be linked to a few rare conditions caused by a problem with your genes: Hermansky-Pudlak syndrome. This is a rare form of albinism that also causes easy bruising and bleeding. Chediak-Higashi syndrome. Another rare form of albinism, this can cause a low red blood cell count (anemia) and an enlarged liver and can make you more likely to get infections. Griscelli syndrome type 2. Also called partial albinism and immunodeficiency syndrome, this is a rare condition that’s caused by a faulty gene. Symptoms include light skin, silver hair, and serious problems with your immune system that can eventually damage organs and tissues.

• #42 Albinism – StatPearls – NCBI Bookshelf

  https://www.ncbi.nlm.nih.gov/books/NBK519018/

  OCA7: Autosomal recessive. The LRMDA gene (leucine-rich melanocyte differentiation associated protein) codes for a protein thought to play a role in melanocyte differentiation. […] Hermansky-Pudlak syndrome (HPS): Autosomal recessive. Ten different genotypes have been identified, thus far. […] Chediak-Higashi syndrome (CHS): Autosomal recessive. The LYST gene codes for a protein that directs delivery of material into lysosomes. […] Angelman syndrome (AS) and Prader-Willi syndrome (PWS): Both due to spontaneous (not inherited) partial deletions of chromosome 15q. Albinism occurs because the OCA2 allele located on one Chromosome 15q, making subjects haploinsufficient for OCA2 gene product, protein P. […] Ocular albinism (OA1): X-linked. The GPR143 gene product is a G-protein coupled receptor, a mutation in which yields dysfunctional melanosome biogenesis with resultant „macromelanosomes.”

• #43 Albinism: Background, Pathophysiology, Epidemiology

  https://emedicine.medscape.com/article/1200472-overview

  The melanin pathway consists of a series of reactions that converts tyrosine into 2 types of melanin: 1) black-brown eumelanin and 2) red-blond pheomelanin. Genetic variants affecting proteins/enzymes along this pathway inevitably result in reduced melanin production. […] Tyrosinase is the major enzyme (coded on chromosome 11) involved in the series of conversions to form melanin from tyrosine. It is responsible for converting tyrosine to DOPA and then to dopaquinone. Through a sequence of steps, dopaquinone subsequently is converted to either eumelanin or pheomelanin. […] The development of the ocular system is highly dependent on the presence of melanin. Absent or decreased melanin can cause abnormal crisscrossing of optic nerve fibers as a result of misdirected retinogeniculate projections. Melanin is believed to control neuronal target specificity in the brain. […] Genetic counseling is recommended for patients with albinism.

• #44 Understanding Albinism: Causes, Symptoms And Types

  https://www.ajhospital.in/news/understanding-albinism-causes-symptoms-and-types

  Albinism is primarily a genetic condition caused by inherited mutations in specific genes. These genetic mutations disrupt the production, transportation, or storage of melanin in the body. The most common types of albinism, known as oculocutaneous albinism (OCA), are caused by mutations in genes such as OCA1, OCA2, OCA3, and OCA4. Each gene mutation has a unique impact on melanin production, leading to variations in the severity of albinism’s characteristics. […] Albinism is caused by inheriting mutations in specific genes that disrupt the production, transportation, or storage of melanin in the body. […] Albinism is a condition that encompasses various types, each characterised by distinct genetic mutations and unique phenotypic presentations. The most common form is known as oculocutaneous albinism (OCA), which further branches into subtypes based on specific gene mutations.

• #45 Albinism: Background, Pathophysiology, Epidemiology

  https://emedicine.medscape.com/article/1200472-overview

  The melanin pathway consists of a series of reactions that converts tyrosine into 2 types of melanin: 1) black-brown eumelanin and 2) red-blond pheomelanin. Genetic variants affecting proteins/enzymes along this pathway inevitably result in reduced melanin production. […] Tyrosinase is the major enzyme (coded on chromosome 11) involved in the series of conversions to form melanin from tyrosine. It is responsible for converting tyrosine to DOPA and then to dopaquinone. Through a sequence of steps, dopaquinone subsequently is converted to either eumelanin or pheomelanin. […] The development of the ocular system is highly dependent on the presence of melanin. Absent or decreased melanin can cause abnormal crisscrossing of optic nerve fibers as a result of misdirected retinogeniculate projections. Melanin is believed to control neuronal target specificity in the brain. […] Genetic counseling is recommended for patients with albinism.

• #46 What causes albinism (albinos)? – Calcium Zone

  https://archive.imascientist.org.uk/calciumj11-zone/question/what-causes-albinism-albinos.html

  Albinism is a disease in which a person has partial or complete loss of pigmentation (colouring) of the skin, eyes and hair. […] It involves the production of a pigment called melanin. There is a cell called the melanocyte that is responsible for giving skin, hair, and eyes pigmentation. In albinism, the melanocytes are present, but genetic mutations interfere with their pigment production or their ability to distribute it to keratinocytes. […] There are currently five known genetic types of albinism, the most common being oculocutaneous type 1 (OCA1) and type 2 (OCA2). […] Patients with OCA1 have mutations in a gene called TYR that is responsible for creating the enzyme tyrosinase, used by cells to convert the amino acid tyrosine into pigment molecules that colour the skin, hair, and eyes. OCA2, the most common form of albinism in Africa, results from a mutation in the OCA2 gene, which encodes the P protein.

• #47 Albinism | Discover causes & symptoms

  https://www.fightforsight.org.uk/a-z-eye-conditions/albinism/

  Albinism is caused by a fault in one of the genes involved in the production of melanin or the products used to make it. Melanin is important for healthy eye development – without it, the retina and optic nerve (which sends visual information from the retina to the brain) may not develop properly. […] The OCA genes (OCA1 to OCA8), which cause oculocutaneous albinism, mainly affect the enzymes the body uses to generate melanin or other important molecules in the melanin synthesis pathway. Some of the genes (such as OCA1 and OCA3) are related to the coding or control of these enzymes. Other genes (such as OCA2) appear to be related to changing the acidity of the environment in which the enzymes operate. […] Understanding the normal function of these genes has greatly enhanced our understanding of the complex and sophisticated way our body controls pigmentation. There are likely to be more genes and mechanisms that are yet to be discovered in the not too distant future.

• #48 A pathogenic haplotype, common in Europeans, causes autosomal recessive albinism and uncovers missing heritability in OCA1 | Scientific Reports

  https://www.nature.com/articles/s41598-018-37272-5

  A considerable number of these are found to be heterozygous for a pathogenic variant in TYR, and the number is in excess of that explained by carrier frequency. […] The frequency of 28% in the gnomAD database (non-Finnish Europeans) and the identification of unaffected individuals compound heterozygous for a pathogenic variant in TYR and 402Q has excluded that this variant on its own is pathogenic. […] Thus, even though the frequencies of 402Q and 192Y are increased in individuals with a clinical diagnosis of albinism who are heterozygous for a pathogenic variant in TYR or whom have no identified mutation, the frequencies are far too high to be pathogenic. […] We present a pathogenic haplotype, in which pathogenic variant(s) are expected to be found among the shared variants, which are either rare or coding (GYGQ). The haplotypes segregate according to an autosomal recessive inheritance pattern and furthermore, have not been observed in unaffected carriers of a TYR mutation.

• #49 A pathogenic haplotype, common in Europeans, causes autosomal recessive albinism and uncovers missing heritability in OCA1 | Scientific Reports

  https://www.nature.com/articles/s41598-018-37272-5

  The deep intron variant rs147546939G was investigated by minigene analysis and demonstrated to have no effect. […] Comparison of individuals with two pathogenic TYR sequence variants with individuals who are compound heterozygous for the haplotype GYGQ and a pathogenic TYR sequence variant, shows a more severe phenotype in the former group. […] Thus it seems that homozygosity for GYGQ causes a mild albinism phenotype. […] In conclusion, we report a pathogenic haplotype GYGQ in TYR, which may explain 15% of individuals with albinism in our cohort. The haplotype seems to result in a mild phenotype both when in trans to a pathogenic mutation in TYR and when homozygous.

• #50 Albinism: Background, Pathophysiology, Epidemiology

  https://emedicine.medscape.com/article/1200472-overview

  The term albinism originates from the word, albus (Latin for white), and it is an inherited disorder characterized by reduced pigmentation. Albinism is caused by pathogenic variants in genes important for melanin synthesis. […] The phenotypic heterogeneity of albinism is associated with pathogenic variants in genes affecting different parts of the melanin pathway, and in such resulting in reduction at a different level of melanin production. […] With advances in genetics, the classification of albinism has shifted emphasis by genotype as opposed to phenotype alone. Nevertheless, in the past it was known that albinism is an autosomal recessive genetically heterogeneous disorder; however, since progress has been made in the genetics/genomics era, an autosomal dominant form of albinism has been reported.

• #51 Understanding Albinism: Causes, Symptoms And Types

  https://www.ajhospital.in/news/understanding-albinism-causes-symptoms-and-types

  OCA1, resulting from mutations in the OCA1 gene, leads to a complete absence of melanin, the pigment responsible for coloration. […] OCA2, on the other hand, leads to varying degrees of pigmentation. The hair colour and skin tone of individuals with OCA2 can range from light blond to light brown, while their iris colour may appear blue, grey, or hazel. […] Additionally, rarer forms of albinism, such as OCA3 and OCA4, have their own distinct genetic causes and phenotypic variations.

• #52 Understanding Albinism: Causes, Symptoms And Types

  https://www.ajhospital.in/news/understanding-albinism-causes-symptoms-and-types

  OCA1, resulting from mutations in the OCA1 gene, leads to a complete absence of melanin, the pigment responsible for coloration. […] OCA2, on the other hand, leads to varying degrees of pigmentation. The hair colour and skin tone of individuals with OCA2 can range from light blond to light brown, while their iris colour may appear blue, grey, or hazel. […] Additionally, rarer forms of albinism, such as OCA3 and OCA4, have their own distinct genetic causes and phenotypic variations.

• #53 Albinism: Background, Pathophysiology, Epidemiology

  https://emedicine.medscape.com/article/1200472-overview

  The melanin pathway consists of a series of reactions that converts tyrosine into 2 types of melanin: 1) black-brown eumelanin and 2) red-blond pheomelanin. Genetic variants affecting proteins/enzymes along this pathway inevitably result in reduced melanin production. […] Tyrosinase is the major enzyme (coded on chromosome 11) involved in the series of conversions to form melanin from tyrosine. It is responsible for converting tyrosine to DOPA and then to dopaquinone. Through a sequence of steps, dopaquinone subsequently is converted to either eumelanin or pheomelanin. […] The development of the ocular system is highly dependent on the presence of melanin. Absent or decreased melanin can cause abnormal crisscrossing of optic nerve fibers as a result of misdirected retinogeniculate projections. Melanin is believed to control neuronal target specificity in the brain. […] Genetic counseling is recommended for patients with albinism.

• #54 Albinism and Human Eyes: How Does Albinism Affect Vision?

  https://www.allaboutvision.com/conditions/related/how-albinism-affects-vision/

  Albinism is a rare genetic condition that blocks the body’s ability to produce or distribute melanin, the pigment that provides color to the skin, hair and eyes. Melanin is crucial to the development of the optic nerves, and mild to serious vision problems can result from a lack of this pigment. […] People with albinism are at higher risk of developing vision issues because their lack of pigment prevented their eyes from developing normally in utero and through infancy. Common eye problems include: Light sensitivity (photophobia), Refractive errors (astigmatism, myopia, hyperopia), Nystagmus Involuntary movement of the eyes (this can lead to abnormal head positioning), Strabismus Misalignment of the eyes, Foveal hypoplasia A retinal disorder that reduces visual acuity, Optic nerve misrouting Signals from the retina to the brain don’t follow the normal paths, Iris transillumination Lack of pigment allows light to enter through the iris, not just the pupil, Monocular vision Absence of stereo (or binocular) vision, the ability of the eyes to work together, Low vision Best corrected visual acuity of 20/70 or worse.

• #55 Albinism – Dermatologic Disorders – Merck Manual Professional Edition

  https://www.merckmanuals.com/professional/dermatologic-disorders/pigmentation-disorders/albinism

  In OCA type VII, mutations in gene C10ORF11 may play a role in melanocyte differentiation. […] In another group of inherited diseases, a clinical phenotype of OCA occurs in conjunction with bleeding disorders. […] Diagnosis of all types of OCA and OA is based on examination of the skin and eyes. […] Because it may not always be possible to distinguish the subtypes of OCA, genetic testing may be helpful. […] There is no cure for albinism. […] Oculocutaneous albinism is a group of rare, usually autosomal recessive disorders, resulting in hypopigmentation of the skin, hair, and eyes. […] Ocular involvement causes photosensitivity and often nystagmus, strabismus, reduced visual acuity, and loss of binocular stereopsis.

• #56 Albinism – Diagnosis and treatment – Mayo Clinic

  https://www.mayoclinic.org/diseases-conditions/albinism/diagnosis-treatment/drc-20369189

  Genetic testing can help determine the type of albinism and the risk of passing down the gene change to children. […] Albinism is a genetic disorder, and there is currently no cure. […] A specialist in genetics can help identify the specific type of albinism. This information can help guide care, identify possible complications and determine the risk of the condition in future children.

• #57 Information Bulletin – What is Albinism? – National Organization for Albinism and Hypopigmentation

  https://albinism.org/information-bulletin-what-is-albinism/

  OCA4 results from a genetic defect in the SLC45A2 protein that helps the tyrosinase enzyme to function. […] Researchers have also identified several other genes that result in albinism with other features. […] The genes for OCA are located on autosomal chromosomes. […] For a recessive trait (like most types of albinism) to occur, both of the persons chromosomes must carry that trait. […] When both parents carry the albinism gene (and neither parent has albinism) there is a one in four chance at each pregnancy that the baby will be born with albinism. […] Ocular albinism (OA1) is caused by a change in the GPR143 gene that plays a signaling role that is especially important to pigmentation in the eye. […] For couples who have not had a child with albinism, there is no simple test to determine whether a person carries a gene for albinism. […] If parents have had a child with albinism previously, and if that affected child has had a confirmed diagnosis by DNA analysis, there is a way to test in subsequent pregnancies to see if the fetus has albinism.

• #58 Albinism: Background, Pathophysiology, Epidemiology

  https://emedicine.medscape.com/article/1200472-overview

  The melanin pathway consists of a series of reactions that converts tyrosine into 2 types of melanin: 1) black-brown eumelanin and 2) red-blond pheomelanin. Genetic variants affecting proteins/enzymes along this pathway inevitably result in reduced melanin production. […] Tyrosinase is the major enzyme (coded on chromosome 11) involved in the series of conversions to form melanin from tyrosine. It is responsible for converting tyrosine to DOPA and then to dopaquinone. Through a sequence of steps, dopaquinone subsequently is converted to either eumelanin or pheomelanin. […] The development of the ocular system is highly dependent on the presence of melanin. Absent or decreased melanin can cause abnormal crisscrossing of optic nerve fibers as a result of misdirected retinogeniculate projections. Melanin is believed to control neuronal target specificity in the brain. […] Genetic counseling is recommended for patients with albinism.

• #59 Albinism – Diagnosis and treatment – Mayo Clinic

  https://www.mayoclinic.org/diseases-conditions/albinism/diagnosis-treatment/drc-20369189

  Genetic testing can help determine the type of albinism and the risk of passing down the gene change to children. […] Albinism is a genetic disorder, and there is currently no cure. […] A specialist in genetics can help identify the specific type of albinism. This information can help guide care, identify possible complications and determine the risk of the condition in future children.

• #60 Oculocutaneous albinism: MedlinePlus GeneticsLock

  https://medlineplus.gov/genetics/condition/oculocutaneous-albinism/

  Oculocutaneous albinism can result from variants (also known as mutations) in several genes, including TYR, OCA2, TYRP1, and SLC45A2. Variants in the TYR gene cause type 1, variants in the OCA2 gene cause type 2, variants in the TYRP1 gene cause type 3, and variants in the SLC45A2 gene cause type 4. Variants in additional genes likely underlie the other forms of this disorder. The genes associated with oculocutaneous albinism are involved in producing a pigment called melanin, which is the substance that gives skin, hair, and eyes their color. In the retina, melanin also plays a role in normal vision. Variants in any of these genes disrupt the ability of cells to make melanin, which reduces pigmentation in the skin, hair, and eyes. A lack of melanin in the retina leads to the vision problems characteristic of oculocutaneous albinism. […] Some individuals with oculocutaneous albinism do not have variants in any of the known associated genes. In these people, the genetic cause of the condition is unknown.

• #61 Information Bulletin – What is Albinism? – National Organization for Albinism and Hypopigmentation

  https://albinism.org/information-bulletin-what-is-albinism/

  Albinism is an inherited genetic condition that reduces the amount of melanin pigment formed in the skin, hair and/or eyes. […] The presence of these eye problems defines the diagnosis of albinism. […] DNA tests can determine the precise type of albinism. Research on albinism genes is ongoing. To date as many as seven forms of oculocutaneous albinism are now recognized OCA1, OCA2, OCA3, OCA4, OCA5, OCA6 and OCA7. […] OCA1, or tyrosinase-related albinism, results from a genetic defect in an enzyme called tyrosinase. This enzyme helps the body to change the amino acid, tyrosine, into pigment. […] OCA2, or P gene albinism, results from a genetic defect in the P protein that helps the tyrosinase enzyme to function. […] OCA3 is rarely described and results from a genetic defect in TYRP1, a protein related to tyrosinase.

• #62 Genetic Causes of Oculocutaneous Albinism in Pakistani Population

  https://www.mdpi.com/2073-4425/12/4/492

  Melanin pigment helps protect our body from broad wavelength solar radiation and skin cancer. Among other pigmentation disorders in humans, albinism is reported to manifest in both syndromic and nonsyndromic forms as well as with varying inheritance patterns. Oculocutaneous albinism (OCA), an autosomal recessive nonsyndromic form of albinism, presents as partial to complete loss of melanin in the skin, hair, and iris. OCA has been known to be caused by pathogenic variants in seven different genes, so far, according to all the currently published population studies. However, the detection rate of alleles causing OCA varies from 50% to 90%. One of the significant challenges of uncovering the pathological variant underlying disease etiology is inter- and intra-familial locus heterogeneity. This problem is especially pertinent in highly inbred populations.

• #63 Genetic Causes of Oculocutaneous Albinism in Pakistani Population

  https://www.mdpi.com/2073-4425/12/4/492

  Besides these cases of single-gene variants, we also found variants of both TYR and OCA2 in different zygosity combinations within family LUAB17. The obtained combination of OCA variants might interact in a novel manner to generate the observed OCA phenotypes, accentuating the significance of genetic interactions towards OCA etiology. Possible digenic inheritance of OCA variants has also previously been proposed in other populations. […] In conclusion, our study expands the genetic spectrum of OCA in the Pakistani population, aids in the complete genetic testing and counseling of families inheriting variants of OCA genes, and raises the question of whether a potential genetic interaction and digenic inheritance of variants in TYR and OCA2 genes can exist.

• #64 Albinism and Low Vision – ConnectCenter

  https://aphconnectcenter.org/visionaware/eye-conditions/eye-conditions-associated-with-blindness-a-b/albinism-6165/

  This is likely the case because they have more significant foveal hypoplasia and optic nerve misrouting. […] Because foveal hypoplasia is atypical development of the fovea, the role the fovea plays in providing sharp, detailed vision is impaired. […] If this is the case, your child may benefit from increased contrast of the environment and increased contrast of print. […] There is no cure for albinism, but a variety of measures can be taken to address some effects of the disease. […] Refractive errors should be diagnosed and treated promptly to maximize visual acuity and minimize amblyopia. […] Absorptive sunlenses/sunglasses can reduce light sensitivity/photosensitivity. […] Genetic counseling can help parents and adult patients with albinism understand the cause and the risks of the condition for future children. […] Emerging therapies: Studies in animal models of the condition have shown promise for gene therapy, in which the abnormal gene is replaced with a normal copy of the gene and results in the reversal of some of the retinal abnormalities.

• #65 Albinism and Human Eyes: How Does Albinism Affect Vision?

  https://www.allaboutvision.com/conditions/related/how-albinism-affects-vision/

  Since albinism results from genetic mutations, a DNA test can confirm which type of OCA a person has if needed. […] The ability to mimic OCA using a cell model is an important breakthrough. It will lead to a greater understanding of how albinism leads to abnormal development of the retina, optic nerve (which carries visual signals to the brain) and fovea (the area in the retina responsible for our sharpest central vision). […] An application of the knowledge gained from this research could help individuals with oculocutaneous albinism considerably. For example, if scientists confirm that foveal development is dependent on the presence of pigment in the RPE, they could, in theory, improve pigmentation in the RPE. This could lead to greatly improved visual acuity in people with OCA.

• #66 Albinism | Discover causes & symptoms

  https://www.fightforsight.org.uk/a-z-eye-conditions/albinism/

  Albinism is caused by a fault in one of the genes involved in the production of melanin or the products used to make it. Melanin is important for healthy eye development – without it, the retina and optic nerve (which sends visual information from the retina to the brain) may not develop properly. […] The OCA genes (OCA1 to OCA8), which cause oculocutaneous albinism, mainly affect the enzymes the body uses to generate melanin or other important molecules in the melanin synthesis pathway. Some of the genes (such as OCA1 and OCA3) are related to the coding or control of these enzymes. Other genes (such as OCA2) appear to be related to changing the acidity of the environment in which the enzymes operate. […] Understanding the normal function of these genes has greatly enhanced our understanding of the complex and sophisticated way our body controls pigmentation. There are likely to be more genes and mechanisms that are yet to be discovered in the not too distant future.

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