Women's Health
Maternity
Testing
Tay-Sachs Disease and Other Ashkenazi Disorders
Certain genetic disorders are more common in people of Ashkenazi
(Eastern European) Jewish descent. These include Tay-Sachs disease,
Canavan disease, cystic fibrosis, Niemann-Pick disease, Fanconi
anemia, Bloom syndrome and Gaucher disease. Each of these diseases
is caused by different genes, but all are inherited the same way.
In order to inherit one of these disorders, there must be a mistake
in both copies of the gene that is responsible for the disorder.
Carriers have a mistake in one copy of the gene and do not have
any symptoms. Your baby can have one of these diseases only if
both parents are carriers for that disease.
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Tay-Sachs disease is a deficiency of the
enzyme hexosaminidase A and causes a harmful substance to build
up in the brain. This leads to deterioration of mental and physical
abilities and usually death by age 5. Tay-Sachs is also more
common in families of French Canadian or Cajun descent.
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Canavans disease is a progressive disorder
of paralysis and blindness. Children usually die in early childhood.
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Niemann-Pick disease causes poor growth
and progressive mental and physical deterioration. Children
usually die by 4 years of age.
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Fanconi anemia is diagnosed in early childhood
with low blood count, short height and learning disabilities
or mental retardation. People with Fanconi anemia are also at
high risk for cancer, especially leukemia.
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Bloom syndrome causes poor growth, immune
system problems and a high rate of cancer. Patients usually
die by the age of 30 due to cancer.
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Gaucher disease is caused by a deficiency
of the enzyme glucocerebrosidase and causes enlargement of the
liver and spleen and destruction of the bones. The more severe
form can affect brain development as well. There are also mild
forms of Gaucher disease that cause very mild symptoms.
If you are of Ashkenazi Jewish descent, your care provider may
offer testing for these disorders. If you test positive for one
of them, your partner should be tested for that disease. If your
partner is also a carrier, there is a 1 in 4 chance (25%) that
your baby will have the disorder you both carry. You can have
a test during the pregnancy (amniocentesis
or chorionic
villus sampling) to see if your baby has the disease. If your
baby is affected, you can choose to terminate or continue the
pregnancy.
If you are French Canadian or Cajun, you care provider may offer
you Tay-Sachs testing.