Choroba tay-sachsa
Zapobieganie i profilaktyka

Choroba Tay-Sachsa to dziedziczna, neurodegeneracyjna choroba genetyczna, prowadząca do przedwczesnego zgonu, dla której nie istnieje skuteczne leczenie. Profilaktyka opiera się głównie na badaniach przesiewowych nosicieli, które obejmują ocenę aktywności enzymu heksozaminidazy A w surowicy lub leukocytach oraz analizę molekularną mutacji genu HEXA. Programy przesiewowe, szczególnie w populacjach wysokiego ryzyka (np. Żydzi aszkenazyjscy, francuscy Kanadyjczycy, Cajunowie), doprowadziły do redukcji liczby przypadków choroby o ponad 90%, przy częstości nosicielstwa około 1:30 i częstości choroby 1:4000 urodzeń w populacji aszkenazyjskiej. Diagnostyka prenatalna (biopsja kosmówki między 10.-14. tygodniem ciąży, amniocenteza między 15.-18. tygodniem) umożliwia wykrycie choroby z ryzykiem poronienia ≤1%. Dla par obojga nosicieli dostępna jest także diagnostyka preimplantacyjna (PGD) w połączeniu z IVF, pozwalająca na selekcję zdrowych zarodków i uniknięcie urodzenia dziecka z chorobą.

  1. Wprowadzenie do profilaktyki choroby Tay-Sachsa
  2. Badania przesiewowe nosicieli
    1. Programy badań przesiewowych w populacjach wysokiego ryzyka
    2. Zalecenia dotyczące badań przesiewowych
  3. Diagnostyka prenatalna
  4. Diagnostyka preimplantacyjna
  5. Poradnictwo genetyczne
    1. Specjalistyczne testy genetyczne
  6. Skuteczność programów profilaktycznych
  7. Ograniczenia i wyzwania w profilaktyce
  8. Przyszłość profilaktyki choroby Tay-Sachsa
  9. Podsumowanie zaleceń profilaktycznych
    1. Kolejne rozdziały

Wprowadzenie do profilaktyki choroby Tay-Sachsa

Choroba Tay-Sachsa jest dziedzicznym schorzeniem genetycznym, które w swojej klasycznej postaci prowadzi do postępującej neurodegeneracji i przedwczesnego zgonu. Mimo że nie istnieje skuteczna metoda leczenia tej choroby, dostępne są liczne strategie profilaktyczne, które znacząco zredukowały częstość jej występowania, szczególnie w populacjach wysokiego ryzyka. Wdrożenie programów badań przesiewowych i poradnictwa genetycznego doprowadziło do zmniejszenia liczby przypadków choroby Tay-Sachsa o ponad 90% w ciągu ostatnich 50 lat w społecznościach Żydów aszkenazyjskich w Stanach Zjednoczonych, Kanadzie i Izraelu.12 Poniżej przedstawiono najważniejsze strategie profilaktyczne stosowane w zapobieganiu wystąpieniu tej choroby.

Badania przesiewowe nosicieli

Badania przesiewowe nosicieli stanowią podstawową strategię profilaktyki choroby Tay-Sachsa. Rozpoczęto je w 1971 roku jako pierwsze badania przesiewowe ukierunkowane na wykrywanie nosicieli choroby genetycznej.1 Badania te są zalecane osobom planującym potomstwo, szczególnie tym pochodzącym z grup wysokiego ryzyka jak Żydzi aszkenazyjscy, francuscy Kanadyjczycy czy Cajunowie, a także osobom z dodatnim wywiadem rodzinnym w kierunku choroby Tay-Sachsa.12

Obecnie dostępne są dwie główne metody wykrywania nosicieli choroby Tay-Sachsa:1

1

Liczne organizacje medyczne, w tym American College of Obstetricians and Gynecologists (ACOG), zalecają, aby badania przesiewowe w kierunku nosicielstwa choroby Tay-Sachsa oferować wszystkim osobom planującym ciążę lub będącym w ciąży, jeśli którakolwiek z nich pochodzi z populacji wysokiego ryzyka.1 W przypadku gdy jedna osoba z pary należy do grupy wysokiego ryzyka i zostanie zidentyfikowana jako nosiciel, drugiemu partnerowi również należy zaproponować badanie.2

Programy badań przesiewowych w populacjach wysokiego ryzyka

Najlepszym przykładem skuteczności badań przesiewowych jest program wykrywania nosicieli wśród Żydów aszkenazyjskich. Jak pokazują dane, przed wprowadzeniem badań przesiewowych częstość występowania choroby Tay-Sachsa w tej populacji wynosiła około 1 na 4000 urodzeń, a częstość nosicielstwa wynosi około 1 na 30 osób.1 Po wprowadzeniu systematycznych badań przesiewowych liczba przypadków choroby Tay-Sachsa w tej populacji spadła o ponad 90%.1

Organizacje takie jak Dor Yeshorim prowadzą anonimowe programy badań przesiewowych dla młodzieży w szkołach średnich w społecznościach ortodoksyjnych Żydów. Wyniki są przechowywane w bazie danych, a młodzi ludzie przed zawarciem małżeństwa mogą sprawdzić, czy oni i ich potencjalny partner są nosicielami tej samej mutacji.1 To podejście pozwala uniknąć małżeństw, w których oboje partnerzy są nosicielami, co eliminuje ryzyko urodzenia dziecka z chorobą Tay-Sachsa.1

W ciągu pierwszych 30 lat od wprowadzenia badań przesiewowych (1969-1998) przebadano ponad 1,3 miliona osób i zidentyfikowano 48 864 nosicieli.1 W Izraelu wprowadzono bezpłatne badania przesiewowe dla całej populacji planującej założenie rodziny, wraz z poradnictwem dla par wymagających konsultacji na podstawie wyników testów.1

Zalecenia dotyczące badań przesiewowych

Organizacja NTSAD (National Tay-Sachs & Allied Diseases Association) zaleca, aby badania przesiewowe były kompleksowe i wysokiej jakości, obejmując testy w kierunku choroby Tay-Sachsa (gen HEXA), choroby Canavan (gen ASPA), choroby GM1 (gen GLB1) i choroby Sandhoffa (gen HEXB).1

W przypadku badań przesiewowych w kierunku choroby Tay-Sachsa rekomenduje się połączenie badania DNA i badania aktywności enzymatycznej dla uzyskania najwyższego poziomu wykrywalności. Większość laboratoriów oferuje tylko badania DNA, dlatego należy wybrać laboratorium wykonujące oba rodzaje testów.1

Istotną rolę odgrywa również edukacja dotycząca badań przesiewowych. W niektórych programach przesiewowych wykorzystuje się pobieranie próbek z policzka (cheekbrush sampling) zamiast pobierania krwi, co znacząco zmniejsza dyskomfort i lęk uczestników, a tym samym zwiększa ich chęć do poddania się badaniom.1

Diagnostyka prenatalna

Dla par, w których oboje partnerzy są nosicielami genu choroby Tay-Sachsa, istnieje 25% ryzyko, że ich dziecko będzie dotknięte tą chorobą.12 W takiej sytuacji diagnostyka prenatalna umożliwia określenie, czy płód odziedziczył wadliwe kopie genu od obojga rodziców.1

Dostępne są dwie główne metody diagnostyki prenatalnej:12

  • Biopsja kosmówki (CVS) – procedura wykonywana między 10. a 14. tygodniem ciąży, polegająca na pobraniu małego fragmentu łożyska
  • Amniocenteza – zabieg wykonywany zwykle między 15. a 18. tygodniem ciąży, polegający na pobraniu małej próbki płynu owodniowego otaczającego płód

12

Obie procedury wiążą się z ryzykiem poronienia wynoszącym 1% lub mniej.1 Choroba Tay-Sachsa może być zdiagnozowana prenatalnie poprzez pomiar aktywności heksozaminidazy w próbkach uzyskanych podczas amniocentezy, biopsji kosmówki lub analizy mutacji.1

Jeśli ojciec nie jest nosicielem, ryzyko wystąpienia choroby Tay-Sachsa u dziecka jest bardzo niskie. Jeśli jednak jest nosicielem, można rozważyć wykonanie amniocentezy lub biopsji kosmówki, które są badaniami diagnostycznymi umożliwiającymi określenie, czy obecna ciąża jest dotknięta chorobą Tay-Sachsa.1

Diagnostyka preimplantacyjna

Pary, w których oboje partnerzy są nosicielami choroby Tay-Sachsa, mogą zdecydować się na diagnostykę genetyczną preimplantacyjną (PGD) w połączeniu z zapłodnieniem in vitro (IVF).12

Proces ten obejmuje:12

  • Pobranie komórek jajowych od matki
  • Zapłodnienie in vitro
  • Badanie zarodków przed implantacją w kierunku obecności genów choroby Tay-Sachsa
  • Selekcję zdrowych zarodków do transferu do macicy matki

12

Ta metoda pozwala uniknąć poczęcia dziecka, które będzie dotknięte chorobą, eliminując konieczność podejmowania trudnych decyzji dotyczących przerwania ciąży w późniejszym etapie.1 Mimo że jest to kosztowna opcja, dla par będących nosicielami, które pragną mieć biologiczne dziecko bez choroby Tay-Sachsa, stanowi ona wiarygodną alternatywę.1

Poradnictwo genetyczne

Poradnictwo genetyczne jest istotnym elementem profilaktyki choroby Tay-Sachsa. Specjaliści z zakresu poradnictwa genetycznego pomagają parom z grup ryzyka zrozumieć:12

  • Ryzyko urodzenia dziecka z chorobą Tay-Sachsa
  • Dostępne opcje badań przesiewowych i diagnostycznych
  • Możliwości reprodukcyjne i planowanie rodziny
  • Psychologiczne i społeczne aspekty związane z chorobą genetyczną

12

Konsultacja z doradcą genetycznym jest szczególnie zalecana dla osób należących do grup wysokiego ryzyka, takich jak Żydzi aszkenazyjscy, francuscy Kanadyjczycy czy Cajunowie, a także dla osób z dodatnim wywiadem rodzinnym w kierunku choroby Tay-Sachsa.12

W przypadku par, w których oboje partnerzy są nosicielami, doradca genetyczny może omówić dostępne opcje, takie jak diagnostyka prenatalna, diagnostyka preimplantacyjna, adopcja czy wykorzystanie dawstwa gamet.1 Te informacje pozwalają parom podejmować świadome decyzje dotyczące planowania rodziny.1

Specjalistyczne testy genetyczne

Osoby zainteresowane określeniem, czy są nosicielami choroby Tay-Sachsa, powinny porozmawiać ze swoim lekarzem o badaniach lub skontaktować się z doradcą genetycznym.1 Aby przeprowadzić badanie molekularne, mutacja genu powodująca chorobę Tay-Sachsa musi być znana w rodzinie.2

W przypadku populacji francusko-kanadyjskiej dostępne są specjalistyczne testy w kierunku delecji charakterystycznej dla tej populacji w genie HEXA.1 Test ten obejmuje amplifikację DNA pacjenta za pomocą specyficznych starterów PCR otaczających delecję, z wykorzystaniem próbek kontrolnych od osób będących heterozygotami pod względem delecji.1

Skuteczność programów profilaktycznych

Programy profilaktyczne choroby Tay-Sachsa są uważane za jeden z najbardziej udanych modeli zapobiegania chorobom genetycznym.1 W wyniku wdrożenia tych programów w Stanach Zjednoczonych i Kanadzie liczba przypadków choroby Tay-Sachsa w populacji żydowskiej zmniejszyła się o ponad 90%.1

Od 1970 roku na całym świecie przebadano dobrowolnie ponad 1,4 miliona osób w celu ustalenia, czy są nosicielami zmutowanego genu odpowiedzialnego za chorobę Tay-Sachsa.1 Dzięki badaniom prenatalnym przeprowadzonym u ponad 3200 ciężarnych kobiet, zapobieżono narodzinom ponad 600 niemowląt z tą śmiertelną chorobą neurodegeneracyjną.1

Sukces tych programów polega na połączeniu:1

  • Ukierunkowanych badań przesiewowych w populacjach wysokiego ryzyka
  • Edukacji i świadomości społecznej
  • Dostępności poradnictwa genetycznego
  • Dostępu do diagnostyki prenatalnej i preimplantacyjnej

1

Warto podkreślić, że spadek liczby przypadków choroby Tay-Sachsa nie wynika z opracowania skutecznego leczenia, ponieważ takowe nie istnieje, ani ze zmniejszenia częstości występowania genów w populacji. Jest to rezultat zwiększonej świadomości i edukacji osób na temat osobistego ryzyka oraz dostępnych opcji profilaktycznych.1

Ograniczenia i wyzwania w profilaktyce

Mimo znaczących sukcesów, programy profilaktyki choroby Tay-Sachsa napotykają pewne wyzwania:12

  • Ograniczona czułość badań przesiewowych w populacji ogólnej – badania genetyczne mogą wykrywać tylko znane mutacje, które różnią się w zależności od grupy etnicznej
  • Pseudodeficyt enzymatyczny – niektóre osoby mogą mieć niską aktywność enzymu, ale nie są nosicielami chorobotwórczej mutacji
  • Dostęp do badań i poradnictwa genetycznego – nie wszystkie populacje mają równy dostęp do tych usług
  • Kwestie etyczne związane z selekcją zarodków i przerywaniem ciąży

12

W przypadku rozszerzonych paneli badań przesiewowych obejmujących wiele chorób genetycznych, ważne jest rozpoznanie ograniczeń badanych mutacji w wykrywaniu nosicieli w populacji ogólnej.1 W obecności wywiadu rodzinnego wskazującego na chorobę Tay-Sachsa, rozszerzone panele badań przesiewowych nie są najlepszym podejściem, chyba że mutacja rodzinna jest uwzględniona w panelu.1

Przyszłość profilaktyki choroby Tay-Sachsa

Sukces programów profilaktycznych choroby Tay-Sachsa stanowi model dla innych chorób genetycznych.12 Doświadczenia z zapobieganiem chorobie Tay-Sachsa mogą być pouczające w erze odkryć związanych z genomem, gdy pojawi się wiele nowych możliwości badań przesiewowych populacji.1

Na podstawie skuteczności programów badań przesiewowych, wiele innych chorób zostało dodanych do panelu badań przesiewowych dla populacji Żydów aszkenazyjskich na przestrzeni lat.1 Podobne programy mogą być implementowane dla innych chorób genetycznych i w innych populacjach wysokiego ryzyka.1

Równolegle do strategii profilaktycznych, trwają badania nad metodami leczenia choroby Tay-Sachsa, w tym:12

1

Chociaż nie istnieje obecnie skuteczne leczenie dla osób urodzonych z chorobą Tay-Sachsa, postępy w badaniach są obiecujące i mogą w przyszłości doprowadzić do opracowania skutecznych metod terapeutycznych.11

Podsumowanie zaleceń profilaktycznych

Na podstawie dostępnych danych i wytycznych, można sformułować następujące zalecenia profilaktyczne:12

  • Osoby planujące ciążę lub będące w ciąży powinny rozważyć badania przesiewowe w kierunku nosicielstwa choroby Tay-Sachsa, niezależnie od pochodzenia etnicznego czy wywiadu rodzinnego
  • Osoby pochodzące z grup wysokiego ryzyka (Żydzi aszkenazyjscy, francuscy Kanadyjczycy, Cajunowie) powinny być szczególnie zachęcane do wykonania badań przesiewowych
  • Badania przesiewowe najlepiej przeprowadzić przed ciążą, aby umożliwić parom poznanie ryzyka reprodukcyjnego i dostępnych opcji
  • W przypadku wykrycia nosicielstwa u obu partnerów, należy skorzystać z poradnictwa genetycznego w celu omówienia dostępnych opcji
  • Badania przesiewowe w kierunku choroby Tay-Sachsa powinny obejmować zarówno badanie DNA, jak i badanie aktywności enzymatycznej dla maksymalnej czułości

12

Implementacja tych zaleceń, w połączeniu z edukacją społeczną i dostępem do poradnictwa genetycznego, może przyczynić się do dalszego zmniejszenia liczby przypadków choroby Tay-Sachsa i związanego z nią cierpienia.12

Kolejne rozdziały

Zapraszamy do dalszego czytania naszego leksykonu.

Wybierz kolejny rozdział z menu poniżej, aby otworzyć nową podstronę kompedium wiedzy i uzyskać szczegółowe informację o leku, substancji lub chorobie.

  1. 18.04.2026
  2. www.leksykon.com.pl

Materiały źródłowe

  • #1 APPENDIX 6. SCIENTIFIC ADVANCES AND SOCIAL RISKS: HISTORICAL PERSPECTIVES OF GENETIC SCREENING PROGRAMS FOR SICKLE CELL DISEASE, TAY-SACHS DISEASE, NEURAL TUBE DEFECTS AND DOWN SYNDROME
    https://biotech.law.lsu.edu/research/fed/tfgt/appendix6.htm
    The majority of those couples who were discovered to be carrying a fetus afflicted with Tay-Sachs disease elected to terminate the pregnancy. […] Since 1971, screening programs directed at the Ashkenazi Jewish population in the United States and Canada have led to a 90 percent reduction in Tay-Sachs disease. […] The Tay-Sachs screening programs are often recalled as a success in the blending of science, bioethics, and disease prevention.
  • #1 Tay-Sachs disease carrier screening: a model for prevention of genetic disease – PubMed
    https://pubmed.ncbi.nlm.nih.gov/10464605/
    Tay-Sachs disease was the first genetic condition for which community-based screening for carrier detection was implemented. […] The outcome of TSD screening over the last 28 years offers convincing evidence that such an effort can dramatically reduce incidence of the disease.
  • #1 Carrier Screening for Genetic Conditions | ACOG
    https://www.acog.org/clinical/clinical-guidance/committee-opinion/articles/2017/03/carrier-screening-for-genetic-conditions
    Screening for TaySachs disease should be offered when considering pregnancy or during pregnancy if either member of a couple is of Ashkenazi Jewish, FrenchCanadian, or Cajun descent. Those with a family history consistent with TaySachs disease also should be offered screening. […] When one member of a couple is at high risk (ie, of Ashkenazi Jewish, FrenchCanadian, or Cajun descent or has a family history consistent with TaySachs disease) but the other partner is not, the high-risk partner should be offered screening. If the high-risk partner is found to be a carrier, the other partner also should be offered screening. […] If TaySachs disease screening is performed as part of pan-ethnic expanded carrier screening, it is important to recognize the limitations of the mutations screened in detecting carriers in the general population. In the presence of a family history of TaySachs disease, expanded carrier screening panels are not the best approach to screening unless the familial mutation is included on the panel.
  • #1 Carrier Screening for Genetic Conditions | ACOG
    https://www.acog.org/clinical/clinical-guidance/committee-opinion/articles/2017/03/carrier-screening-for-genetic-conditions
    Carrier testing can be performed using DNA-based testing (mutation analysis) or hexosaminidase enzymatic activity testing in serum or leukocytes. […] If both partners are found to be carriers of TaySachs disease, genetic counseling and prenatal diagnosis should be offered. TaySachs disease can be diagnosed prenatally by measuring hexosaminidase activity in samples obtained by amniocentesis, chorionic villus sampling, or mutation analysis.
  • #1 Tay-Sachs Disease | Kaiser Permanente
    https://healthy.kaiserpermanente.org/health-wellness/health-encyclopedia/he.tay-sachs-disease.hw182975
    If you are thinking about having a child, the American College of Obstetricians and Gynecologists (ACOG) recommends that: […] Both you and your partner get a screening test if you are both of Ashkenazi Jewish, French-Canadian, or Cajun descent or have a family history of the disease. If both of you test positive as carriers, genetic counseling may help you with making choices. […] Carriers of the Tay-Sachs gene changes can pass the changed gene to their children even though the carriers don’t have the disease. If both you and your partner are carriers, there is a 1-out-of-4 chance (25%) that any child you have will have Tay-Sachs disease.
  • #1 Tay-Sachs disease – Knowledge and References – Taylor & Francis
    https://taylorandfrancis.com/knowledge/Medicine_and_healthcare/Medical_genetics/Tay-Sachs_disease/
    Tay-Sachs disease is transmitted as an autosomal recessive disease. The gene frequency in Ashkenazi Jews has been calculated to be approximately one in 30. This would predict an annual incidence of one in 4000 births with Tay-Sachs disease among parents from this population. These frequencies were so high that it became practical to undertake programs of prevention through heterozygote detection. […] The prototypical successful carrier screening program is Tay-Sachs disease (TSD) carrier screening in Ashkenazi Jewish (AJ) communities. TSD screening programs were developed in collaboration with Ashkenazi Jewish communities, included strong educational and counseling components, and adapted screening strategies to the needs of the target population. […] Carrier screening for TSD was found to be so successful that a number of other diseases have been added to the Ashkenazi Jewish screening panel over the years. […] Furthermore, the potential donor should ordinarily not be heterozygous for an autosomal recessive gene known to be prevalent in the donor’s ethnic background. This includes […] Tay-Sachs disease in Jews of Eastern European descent.
  • #1 Tay-Sachs and Carrier Screening: How They Shaped the Jewish Community – Norton & Elaine Sarnoff Center for Jewish Genetics
    https://www.jewishgenetics.org/articles/tay-sachs-and-carrier-screening-how-they-shaped-the-jewish-community/
    Many people have heard of Tay-Sachs disease, but what have they heard? […] Community health organizations, like the Sarnoff Center, have provided resources to make this happen. […] The first community carrier screening event was held in 1971 at a synagogue in Maryland. Trained volunteers and physicians drew blood from over 1,500 people, which revealed if they had a possibility of having a child with Tay-Sachs. For the first time, people had knowledge about personal risk of having affected kids. Other Jewish communities wanted to do something similar. […] The number of babies born with Tay-Sachs has reduced over 90% in the last 50 years. The reduction of cases of Tay-Sachs is not due to a cure, as there is not one yet. Carrier frequency in Jewish populations also has not changed. It is due to people being more educated about personal risk and taking the time to learn what they can do for prevention.
  • #1 Prevention of Tay–Sachs disease – Wikipedia
    https://en.wikipedia.org/wiki/Prevention_of_Tay%E2%80%93Sachs_disease
    For preventing TaySachs disease, three main approaches have been used to prevent or reduce the incidence of TaySachs disease in those who are at high risk: […] Prenatal diagnosis. If both parents are identified as carriers, prenatal genetic testing can determine whether the fetus has inherited a defective copy of the gene from both parents. […] Mate selection. In Orthodox Jewish circles, the organization Dor Yeshorim carries out an anonymous screening program so that couples who are likely to conceive a child with TaySachs or another genetic disorder can avoid marriage. […] Preimplantation genetic diagnosis. By retrieving the mother’s eggs for in vitro fertilization and conceiving a child outside the womb, it is possible to test the embryo prior to implantation. Only healthy embryos are selected for transfer into the mother’s womb.
  • #1 Tay–Sachs disease – Wikipedia
    https://en.wikipedia.org/wiki/Tay%E2%80%93Sachs_disease
    Three main approaches have been used to prevent or reduce the incidence of TaySachs: […] Prenatal diagnosis. If both parents are identified as carriers, prenatal genetic testing can determine whether the fetus has inherited a defective gene copy from both parents. Chorionic villus sampling (CVS), the most common form of prenatal diagnosis, can be performed between 10 and 14 weeks of gestation. Amniocentesis is usually performed at 15-18 weeks. These procedures have risks of miscarriage of 1% or less. […] Preimplantation genetic diagnosis. By retrieving the mother’s eggs for in vitro fertilization, it is possible to test the embryo for the disorder before implantation. Healthy embryos are then selected and transferred into the mother’s womb, while unhealthy embryos are discarded. In addition to TaySachs disease, preimplantation genetic diagnosis has been used to prevent cystic fibrosis and sickle cell anemia among other genetic disorders. […] Pre-marriage screening. In Orthodox Jewish circles, the organization Dor Yeshorim carries out an anonymous screening program so that carriers for TaySachs and other genetic disorders can avoid marrying each other.
  • #1 Prevention of Tay–Sachs disease – Wikipedia
    https://en.wikipedia.org/wiki/Prevention_of_Tay%E2%80%93Sachs_disease
    Screening for TSD is carried out with two possible objectives: Carrier testing seeks to detect whether an individual unaffected by the disease is carrying one copy of a mutation. […] Prenatal testing seeks to determine whether the fetus has inherited two defective copies, one from each parent. […] Both carrier and prenatal testing using enzyme assay became available in the 1970s. […] In the first 30 years of testing, from 1969 through 1998, more than 1.3 million persons were tested, and 48,864 carriers were identified.
  • #1 Azthena logo with the word Azthena
    https://www.news-medical.net/health/Tay-Sachs-Disease-Society-and-Culture.aspx
    Tay-Sachs disease is a genetic disease that has been at the forefront of scientific research on inheritance patterns, as well as for those exploring the possibility of disease prevention. […] In particular, some Jewish communities have been largely involved in supporting the development of screening programs to help with mate selection and ultimately prevent disease occurrence. […] The introduction of genetic tests that were sensitive to the mutations of carriers for Tay-Sachs in 1971 was met with enthusiasm, especially from certain ethnic groups, such as those living in Israel. […] Ashkenazi Jews, for example, got involved with the genetic screening tests early on to enable safer mate selection and reduce the risk of having a child with Tay-Sachs disease. […] The initial success of this program led to the country of Israel offering both free genetic screening for the entire Israeli population that are planning to start a family, as well as counseling for couples that require advice based on test results.
  • #1 Carrier Screening – NTSAD
    https://ntsad.org/support-for-families/carrier-screening/
    If you have Ashkenazi heritage, it’s a good idea to be screened, even if your partner is not Jewish. […] Carrier screening is recommended for anyone planning a pregnancy or who is already pregnant, regardless of their ethnicity or family history of genetic diseases. Ideally, carrier screening should be performed before pregnancy to allow couples to learn about their reproductive risk and explore options available. […] Consider what carrier screening has done to reduce the incidence of Tay-Sachs disease in the Jewish population. The number of babies born with Tay-Sachs has been reduced by over 90% in the last 50 years because people learned about their personal reproductive risks through widespread implementation of carrier screening programs and genetic counseling. […] NTSAD encourages everyone to make sure their carrier screening test is comprehensive and high quality, and that it includes testing for Tay-Sachs (HEXA gene), Canavan (ASPA gene), GM1 gangliosidosis (GLB1 gene), and Sandhoff (HEXB gene) diseases.
  • #1 Carrier Screening – NTSAD
    https://ntsad.org/support-for-families/carrier-screening/
    If you and your partner are carriers for the same recessive disease, there’s a 25% chance that your child will be affected with the disease even if you already have a child who is unaffected. […] If the father is not found to be a carrier, your baby is at very low risk for Tay-Sachs disease. If he is a carrier, you can consider doing an amniocentesis or chorionic villus sampling (CVS). These are diagnostic tests that will be able to tell you if your current pregnancy is affected with Tay-Sachs disease or is unaffected. […] A combination of DNA and enzyme testing is strongly recommended for Tay-Sachs screening for the highest level of detection. Most labs only offer DNA testing for Tay-Sachs. Be sure to request a laboratory that performs both DNA and enzyme testing.
  • #1 Tay Sachs disease carrier screening in schools: Educational alternatives and cheekbrush sampling | Genetics in Medicine
    https://www.nature.com/articles/gim2005120
    Purpose: Tay Sachs disease carrier screening programs have been offered successfully worldwide since 1970. The programs typically offer education, testing, and counseling to provide reproductive choices. […] Cheekbrush sampling is preferred to blood sampling and should be implemented into current practices for offering genetic screening programs. […] The availability of a sensitive and specific test that is acceptable to the community is one of the World Health Organization guidelines for the introduction of population screening. […] This short-term evaluation of a TSD screening program found that education plays a critical role in allowing informed decisions about testing to be made and minimizing the psychosocial harms that possibly may arise. The offer of testing within schools provides a convenient setting, and cheekbrush sampling is able to significantly decrease participants’ discomfort and anxiety about testing, which is a known testing deterrent.
  • #1 Azthena logo with the word Azthena
    https://www.news-medical.net/health/Tay-Sachs-Disease-Prevention.aspx
    Tay-Sachs is a genetic disease that can be prevented through certain methods of mate selection, antenatal screening, and preimplantation genetic diagnosis. These techniques can be utilized to reduce the likelihood of individuals being born with Tay-Sachs disease, as a way of prevention. […] This knowledge has been used in Orthodox Jewish circles to assist couples in choosing a suitable mate to ensure their children will not be affected by the condition. An organization called Dor Yeshorim runs an anonymous screening program for the disease with blood tests of adolescents in high school. […] If both parents that are expecting a child are known to be genetic carriers of Tay-Sachs disease, there is a 25% chance that any children will be affected by the condition. Antenatal testing can be used in this instance to determine if the fetus is likely to be affected by the disease. […] Couples that are both known genetic carriers of Tay-Sachs disease can opt for pre-implantation genetic diagnosis to avoid conceiving a child that will be affected by the disease.
  • #1 Tay-Sachs disease – Diagnosis and treatment – Mayo Clinic
    https://www.mayoclinic.org/diseases-conditions/tay-sachs-disease/diagnosis-treatment/drc-20378193
    Prenatal testing for Tay-Sachs disease can be done during pregnancy by removing a tiny piece of the placenta (chorionic villi sampling) or by removing a small sample of the amniotic fluid around the baby (amniocentesis). […] Explore Mayo Clinic studies testing new treatments, interventions and tests as a means to prevent, detect, treat or manage this condition.
  • #1 Tay-Sachs Disease: Treatment and Prevention – Terapia Online Presencial Madrid | Mentes Abiertas
    https://www.mentesabiertaspsicologia.com/blog-psicologia/tay-sachs-disease-treatment-and-prevention
    It is important to screen for carriers of Tay disease. -Sachs in couples who are considering having children, especially if there is a family history of the disease. […] Since Tay-Sachs disease Tay-Sachs is of genetic origin, prevention focuses on the early identification of carrier individuals through genetic testing and genetic counseling to evaluate the risk of transmitting the disease to offspring. […] Couples who know they are carriers of Tay-Sachs disease may choose to undergo prenatal testing to determine if their unborn child is affected by the disease. […] In cases of couples in which both are carriers, in vitro fertilization with prior genetic diagnosis (IVF-PGD) may be an option to select unaffected embryos before implantation, thus minimizing the risk of transmitting the disease to offspring. […] Genetic education and counseling are essential to help couples make informed decisions about family planning and prevent the transmission of Tay-Sachs disease to future generations.
  • #1 Tay-Sachs Disease | Embryo Project Encyclopedia
    https://embryo.asu.edu/pages/tay-sachs-disease
    Tay-Sachs Disease can be diagnosed through enzymatic testing or DNA testing, including prenatal testing by amniocentesis or chorionic villus sampling. Carrier testing and aggressive community initiatives have been effective measures of prevention. […] The goal of such testing is to prevent the conception or birth of at-risk babies, with termination being a commonly chosen solution. For Tay-Sachs carriers who wish to bear a normal child, in vitro fertilization followed by testing of individual blastomeres and implantation of non-affected embryos is a reliable though expensive option. […] As of 2010, primary research initiatives include gene therapy, the development of ganglioside inhibitors, chaperone therapy, cord blood transplant, and enzyme replacement therapy. Though no current cures exist for those born with Tay-Sachs disease, progress in the search is promising.
  • #1 Tay-Sachs Disease: What It Is, Causes, Symptoms & Treatment
    https://my.clevelandclinic.org/health/diseases/14348-tay-sachs-disease
    Theres no known way to prevent Tay-Sachs disease. […] To learn more about your risk of having a child with a genetic condition like Tay-Sachs disease, talk to your healthcare provider about preconception counseling and genetic testing before getting pregnant. Your healthcare provider can help you plan for a future pregnancy.
  • #1 Tay-Sachs disease – ThinkGenetic Foundation
    https://thinkgenetic.org/diseases/tay-sachs-disease/
    As of 2017, the incidence of Tay-Sachs disease in many communities has decreased due to implementation of population-based screening programs. […] In a family with Tay-Sachs disease, tests can be done to see whether other family members are carriers for the disorder. […] A newborn child in a family with a history of Tay-Sachs disease should be tested through molecular genetic testing. […] If known, all siblings and other at-risk relatives can be tested. […] Doctors strongly recommend that people of Ashkenazi Jewish heritage undergo carrier screening for Tay-Sachs disease. […] Carrier screening is usually done through a doctors office or a hospital-based medical genetics program. […] Family planning is an important step for people at risk for having a child with a genetic disorder.
  • #1 Tay-Sachs disease – ThinkGenetic Foundation
    https://thinkgenetic.org/diseases/tay-sachs-disease/
    A consultation with a genetic counselor is important to learn potential risk to the child and reproductive options for the couple. […] If both parents have a nonfunctioning copy of HEXA gene, there is a 25% for each pregnancy that a child with have the disorder. […] If you are interested in finding out if you are a carrier for Tay-Sachs disease, talk to your doctor about testing or contact a genetic counselor in your area. […] The gene change(s) that causes Tay-Sachs disease must be known in a family to do molecular genetic testing (which can detect these changes). […] Talk to your doctor or a genetic counselor in your area to discuss the risks and benefits of prenatal diagnosis.
  • #1 Tay-Sachs Disease via the French Canadian Deletion in the HEXA Gene Test – PreventionGenetics
    https://www.preventiongenetics.com/testInfo?val=Tay%252DSachs-Disease-via-the-French-Canadian-Deletion-in-the-HEXA-Gene
    Candidates for this test are patients with a clinical diagnosis of Tay Sachs disease and biological relatives of patients who are known to have the French Canadian deletion in the HEXA gene. This test is recommended as a first step for patients of French Canadian origin. […] This test involves amplification of patient DNA with specific PCR primers that flank the deletion. Positive control samples include samples from two individuals from the French Canadian population, who are known to be heterozygous for the deletion. A healthy individual known to be a non-carrier of the deletion is included as a negative control.
  • #1
    https://link.springer.com/article/10.1007/PL00014401
    Since 1970, more than 1.4 million individuals worldwide have been screened voluntarily to determine if they are carriers of the mutant gene for Tay-Sachs Disease (TSD). […] Through prenatal testing of more than 3200 pregnancies, births of over 600 infants with this uniformly fatal neurodegenerative disease have been prevented. […] In the United States and Canada, the incidence of TSD in the Jewish population has been reduced by more than 90%. […] Many new opportunities for population-based screening will be evident in this era of genome-related discovery. Accordingly, some of the experiences with Tay-Sachs disease prevention may be instructive.
  • #1 Tay-Sachs disease, screening and prevention : based on the First International Conference on Tay-Sachs Disease, Screening and Prevention, Palm Springs, California / editor, Michael M. Kaback ;ssociate editors, David L. Rimoin, John S. O’Brien. | Well
    https://wellcomecollection.org/works/a9xksccj/items?canvas=30&page=5
    The association is deeply grateful to all those who have made achievements in Tay-Sachs and the allied disorders. […] The tenets that have been set down by Dr. Michael Kaback have been the basis of all the screening programs that have been and continue to be instituted, supported, and conducted by our association in cities across the country. […] And since the entire success of screening programs is predicated on, and directly proportionate to, the in-depth education of the medical profession, the rabbinate, and the lay community, we are now embarking on a massive national education campaign. […] We believe that such a program of education will aid everyone involved in screening and therefore accelerate the elimination by prevention of Tay-Sachs disease until the day when continued research will surely result in the discovery of an effective treatment or cure.
  • #1 Eight novel mutations in the HEXA gene | Genetics in Medicine
    https://www.nature.com/articles/gim200231
    Population-based carrier screening programs, particularly in the Ashkenazi Jewish population, rely on carrier screening and genetic counseling (including prenatal diagnosis) to reduce the incidence of TSD in this population. […] In the California Tay-Sachs Disease Prevention program, all individuals that test as carriers by enzymatic methods are then subjected to DNA testing (examining only the six common mutations described above). […] In summary, identification of these eight novel mutations adds to the extensive mutational spectrum for the -subunit of the HEXA gene, and contributes to more accurate carrier identification, diagnosis, and prognosis for TSD.
  • #1 SciELO Brazil – The frequency of Tay-Sachs disease causing mutations in the Brazilian Jewish population justifies a carrier screening program The frequency of Tay-Sachs disease causing mutations in the Brazilian Jewish population justifies a carrier scre
    https://www.scielo.br/j/spmj/a/HLkR8z3f9wnw3tQQM3P35wn/
    The frequency of Tay-Sachs disease carriers among the Ashkenazi Jewish population of Brazil is similar to that of other countries where carrier screening programs have led to a significant decrease in disease incidence. Therefore, it is justifiable to implement a Tay-Sachs disease carrier screening program for the Brazilian Jewish population. […] Based on the efficiency of screening programs for Tay-Sachs disease in alerting carrier couples and decreasing the disease incidence in other countries, a similar program should be implemented for the Brazilian Jewish population. In addition, physicians should recommend testing for Tay-Sachs disease mutations for individuals of Ashkenazi Jewish ancestry at reproductive age.
  • #1 The Mystery of Tay-Sachs as a
    https://sinaiandsynapses.org/content/the-mystery-of-tay-sachs-as-a-jewish-disease/
    In 1980, I was working for the Tay-Sachs disease prevention program in Los Angeles. This program tested people, principally Ashkenazi Jews, for being carriers of Tay-Sachs Disease. […] After the screening and prevention programs spearheaded by Dr. Kaback became established in 1970, the number of Tay-Sachs cases in the Ashkenazi Jewish population plummeted to the point where there are said to be more Tay-Sachs carriers who are non-Jews than among Ashkenazi Jews. […] What is the take-home message from all this information? The most important thing to bear in mind is that for all the success there has been in making Tay-Sachs disease less of a problem, it still cannot be cured, its cause has not been eliminated, and there is still no treatment. It remains a threat. The screening, testing, pregnancy-termination or avoided-relationship tactics we employ in order to get around the devastation to families does not eliminate the fundamental problem. And the underlying cause continues to lurk in the Ashkenazi Jewish population. […] The fact that Tay-Sachs disease has been essentially eliminated from the population in which it was most frequent is glowing testimony to what we can do when we try.
  • #2 Tay-Sachs Disease: Treatments, Symptoms, Risks, and More
    https://www.healthline.com/health/neurological-health/tay-sachs-disease
    Because Tay-Sachs is inherited, there is no way to prevent it except through screening. Before starting a family, both parents can undertake genetic testing to see if theyre carriers of the disease. This is most important for people at elevated risk, such as Ashkenazi Jews or people with a family history of Tay-Sachs. […] Screening for carriers of Tay-Sachs started in the 1970s and has reduced the number of Ashkenazi Jews born with Tay-Sachs in the United States and Canada by over 90 percent. […] Speak with a genetic counselor if youre thinking about starting a family, and you or your partner believe you might be carriers of Tay-Sachs disease.
  • #2 Carrier Screening – NTSAD
    https://ntsad.org/support-for-families/carrier-screening/
    If you have Ashkenazi heritage, it’s a good idea to be screened, even if your partner is not Jewish. […] Carrier screening is recommended for anyone planning a pregnancy or who is already pregnant, regardless of their ethnicity or family history of genetic diseases. Ideally, carrier screening should be performed before pregnancy to allow couples to learn about their reproductive risk and explore options available. […] Consider what carrier screening has done to reduce the incidence of Tay-Sachs disease in the Jewish population. The number of babies born with Tay-Sachs has been reduced by over 90% in the last 50 years because people learned about their personal reproductive risks through widespread implementation of carrier screening programs and genetic counseling. […] NTSAD encourages everyone to make sure their carrier screening test is comprehensive and high quality, and that it includes testing for Tay-Sachs (HEXA gene), Canavan (ASPA gene), GM1 gangliosidosis (GLB1 gene), and Sandhoff (HEXB gene) diseases.
  • #2 Carrier Screening for Genetic Conditions | ACOG
    https://www.acog.org/clinical/clinical-guidance/committee-opinion/articles/2017/03/carrier-screening-for-genetic-conditions
    Screening for TaySachs disease should be offered when considering pregnancy or during pregnancy if either member of a couple is of Ashkenazi Jewish, FrenchCanadian, or Cajun descent. Those with a family history consistent with TaySachs disease also should be offered screening. […] When one member of a couple is at high risk (ie, of Ashkenazi Jewish, FrenchCanadian, or Cajun descent or has a family history consistent with TaySachs disease) but the other partner is not, the high-risk partner should be offered screening. If the high-risk partner is found to be a carrier, the other partner also should be offered screening. […] If TaySachs disease screening is performed as part of pan-ethnic expanded carrier screening, it is important to recognize the limitations of the mutations screened in detecting carriers in the general population. In the presence of a family history of TaySachs disease, expanded carrier screening panels are not the best approach to screening unless the familial mutation is included on the panel.
  • #2 Tay-Sachs Disease | Kaiser Permanente
    https://healthy.kaiserpermanente.org/health-wellness/health-encyclopedia/he.tay-sachs-disease.hw182975
    If you are thinking about having a child, the American College of Obstetricians and Gynecologists (ACOG) recommends that: […] Both you and your partner get a screening test if you are both of Ashkenazi Jewish, French-Canadian, or Cajun descent or have a family history of the disease. If both of you test positive as carriers, genetic counseling may help you with making choices. […] Carriers of the Tay-Sachs gene changes can pass the changed gene to their children even though the carriers don’t have the disease. If both you and your partner are carriers, there is a 1-out-of-4 chance (25%) that any child you have will have Tay-Sachs disease.
  • #2 Tay–Sachs disease – Wikipedia
    https://en.wikipedia.org/wiki/Tay%E2%80%93Sachs_disease
    Three main approaches have been used to prevent or reduce the incidence of TaySachs: […] Prenatal diagnosis. If both parents are identified as carriers, prenatal genetic testing can determine whether the fetus has inherited a defective gene copy from both parents. Chorionic villus sampling (CVS), the most common form of prenatal diagnosis, can be performed between 10 and 14 weeks of gestation. Amniocentesis is usually performed at 15-18 weeks. These procedures have risks of miscarriage of 1% or less. […] Preimplantation genetic diagnosis. By retrieving the mother’s eggs for in vitro fertilization, it is possible to test the embryo for the disorder before implantation. Healthy embryos are then selected and transferred into the mother’s womb, while unhealthy embryos are discarded. In addition to TaySachs disease, preimplantation genetic diagnosis has been used to prevent cystic fibrosis and sickle cell anemia among other genetic disorders. […] Pre-marriage screening. In Orthodox Jewish circles, the organization Dor Yeshorim carries out an anonymous screening program so that carriers for TaySachs and other genetic disorders can avoid marrying each other.
  • #2 Tay-Sachs Disease: Causes, Symptoms, Diagnosis, and Treatment • Yesil Health
    https://yesilhealth.com/your-health/tay-sachs-disease-causes-symptoms-diagnosis-and-treatment/
    Tay-Sachs disease can be prevented through genetic testing and counseling. If both parents are carriers of the mutated gene, they can undergo prenatal testing to determine if the fetus has inherited the disease. Additionally, carrier testing can identify individuals who are at risk of passing the disease to their offspring. […] Carrier screening is a test that can determine if an individual is a carrier of the Tay-Sachs disease gene. This is typically recommended for individuals of Ashkenazi Jewish descent, as they are more likely to be carriers of the gene. The test involves a simple blood test or cheek swab. […] Prenatal testing can detect Tay-Sachs disease in a fetus as early as 10-12 weeks into pregnancy. This can be done through chorionic villus sampling (CVS) or amniocentesis. […] PGD is a technique used in conjunction with in vitro fertilization (IVF). It involves testing embryos for the Tay-Sachs disease gene before they are implanted in the uterus. This can help ensure that only embryos without the gene are implanted, reducing the risk of passing the condition to offspring.
  • #2 Tay-Sachs disease – Symptoms and causes – Mayo Clinic
    https://www.mayoclinic.org/diseases-conditions/tay-sachs-disease/symptoms-causes/syc-20378190
    If you have a family history of Tay-Sachs disease or if you’re a member of a high-risk group and plan to have children, health care providers strongly recommend genetic testing and genetic counseling. […] A blood test can be used to identify carriers of the HEXA gene change that causes Tay-Sachs disease. Genetic counseling is recommended following testing.
  • #2 Tay-Sachs disease – ThinkGenetic Foundation
    https://thinkgenetic.org/diseases/tay-sachs-disease/
    A consultation with a genetic counselor is important to learn potential risk to the child and reproductive options for the couple. […] If both parents have a nonfunctioning copy of HEXA gene, there is a 25% for each pregnancy that a child with have the disorder. […] If you are interested in finding out if you are a carrier for Tay-Sachs disease, talk to your doctor about testing or contact a genetic counselor in your area. […] The gene change(s) that causes Tay-Sachs disease must be known in a family to do molecular genetic testing (which can detect these changes). […] Talk to your doctor or a genetic counselor in your area to discuss the risks and benefits of prenatal diagnosis.
  • #2 Tay-Sachs Disease: Symptoms, Causes, Treatment, Prevention
    https://www.webmd.com/parenting/baby/what-is-tay-sachs-disease
    You can have a blood test that analyzes your genes or the levels of the Hex-A protein in your blood to tell you whether you are a Tay-Sachs carrier. […] If two people planning to have children find out that theyre both carriers, a genetic counselor can help them review the options for lowering the chances of having a baby with Tay-Sachs.
  • #2 Tay-Sachs disease
    https://www.redalyc.org/journal/5763/576366816018/html/
    TSD was first described in 1881, but its etiology remained unknown for a long time, and affected newborns could only be diagnosed after the first clinical manifestations. […] Large-scale detection in specific ethnic groups decreased its incidence by 90% in the USA, mainly in groups where the rate of the disease was higher, as in people of Ashkenazi Jewish descent. […] For this reason, Tay-Sachs disease is considered a prototype disease for targeted ethnic evaluations. […] This limited number of prevalent mutations has led to the design of a prevention program (carrier detection) that has successfully reduced the occurrence of TSD in the Ashkenazi population. […] Prenatal screening for TSD was introduced in 1971 in the U.S. and throughout history its application has been directed only at Ashkenazi Jewish populations.
  • #2 Tay-Sachs disease – Knowledge and References – Taylor & Francis
    https://taylorandfrancis.com/knowledge/Medicine_and_healthcare/Medical_genetics/Tay-Sachs_disease/
    Tay-Sachs disease is transmitted as an autosomal recessive disease. The gene frequency in Ashkenazi Jews has been calculated to be approximately one in 30. This would predict an annual incidence of one in 4000 births with Tay-Sachs disease among parents from this population. These frequencies were so high that it became practical to undertake programs of prevention through heterozygote detection. […] The prototypical successful carrier screening program is Tay-Sachs disease (TSD) carrier screening in Ashkenazi Jewish (AJ) communities. TSD screening programs were developed in collaboration with Ashkenazi Jewish communities, included strong educational and counseling components, and adapted screening strategies to the needs of the target population. […] Carrier screening for TSD was found to be so successful that a number of other diseases have been added to the Ashkenazi Jewish screening panel over the years. […] Furthermore, the potential donor should ordinarily not be heterozygous for an autosomal recessive gene known to be prevalent in the donor’s ethnic background. This includes […] Tay-Sachs disease in Jews of Eastern European descent.
  • #2 Tay-Sachs disease
    https://www.redalyc.org/journal/5763/576366816018/html/
    This screening has been associated with a 90% reduction in the incidence of the disease in populations that have been intervened, mainly in the USA, Israel and Canada. […] At present, TSD carrier detection assays are designed to exclusively search for the most common mutations in a gene; carrier status can be determined by molecular analysis that detects genetic mutations in the hexosaminidase A sub-unit. […] Diagnosis should be suspected from the onset of the first symptoms and the earliest clinical manifestations of the disease, which include excessive responses to sound and progressive loss of motor skills that had previously been acquired until the onset of psychomotor retardation. […] Even though several alleles associated with the disease have been identified, there is no approved effective treatment for TSD or a way to stop its progression. […] Gene therapies to restore enzymes in patients could cure such diseases, but time, vector type and kinetics in enzyme production require extensive optimization.
  • #2 Tay-Sachs Disease: Treatment and Prevention – Terapia Online Presencial Madrid | Mentes Abiertas
    https://www.mentesabiertaspsicologia.com/blog-psicologia/tay-sachs-disease-treatment-and-prevention
    It is important to screen for carriers of Tay disease. -Sachs in couples who are considering having children, especially if there is a family history of the disease. […] Since Tay-Sachs disease Tay-Sachs is of genetic origin, prevention focuses on the early identification of carrier individuals through genetic testing and genetic counseling to evaluate the risk of transmitting the disease to offspring. […] Couples who know they are carriers of Tay-Sachs disease may choose to undergo prenatal testing to determine if their unborn child is affected by the disease. […] In cases of couples in which both are carriers, in vitro fertilization with prior genetic diagnosis (IVF-PGD) may be an option to select unaffected embryos before implantation, thus minimizing the risk of transmitting the disease to offspring. […] Genetic education and counseling are essential to help couples make informed decisions about family planning and prevent the transmission of Tay-Sachs disease to future generations.

Zobacz więcej

delecja poronienie choroba Sandhoffa neurodegeneracja enzymatyczna terapia zastępcza terapia genowa badanie przesiewowe terapia chaperonowa przeszczep krwi pępowinowej zapłodnienie in vitro biopsja kosmówki heksozaminidaza A Żydzi aszkenazyjscy American College of Obstetricians and Gynecologists diagnostyka genetyczna preimplantacyjna choroba Tay-Sachsa poradnictwo genetyczne płyn owodniowy gen HEXA amniocenteza