Ashkenazi Jews

The ethnic and religious group known as the Ashkenazi Jews has been extensively studied for diseases occuring at higher frequencies compared to non-Jewish groups. These diseases include:

• Bloom syndrome
• Breast cancer and ovarian cancer
  • Certain disease-causing deletions in the BRCA1 and BRCA2 genes are more common among Ashkenazi Jews.
  • BRCA1 5382insC and 185delAG, and BRCA2 6174delT, are considered the founder mutations in this population.
• Canavan disease
  • 2 SNPs are found primarily in Jewish groups: rs28940279 and rs12948217
• Colorectal cancer due to the hereditary nonpolyposis colorectal cancer (HNPCC) gene
• Congenital adrenal hyperplasia (non-classical form)
• Crohn's disease (the NOD2/CARD15 locus appears to be implicated)
• Cystic fibrosis
• Factor XI deficiency, also known as hemophilia C
• Familial dysautonomia, also known as Riley-Day syndrome
• Familial hyperinsulinism
• Fanconi anemia
• Lysosomal storage disease of various types
  • Gaucher disease, the most common lysosomal storage disease
  • Glycogen storage disease type 1A, also known as von Gierke disease
    • rs1801175 is the prevalent mutation
  • Mucolipidosis type IV
  • Niemann-Pick disease
  • Tay-Sachs disease
• Maple Syrup Urine Disease
  • The most common mutation is rs28934895, also known as R183P
• Pemphigus vulgaris
• Torsion dystonia

Many of these diseases are inherited in an autosomal recessive manner, meaning that carriers are not affected; a child does not develop the disease unless he or she inherits the risk allele from both parents.

Because some risk alleles appear at a high frequency among Ashkenazi Jews, the American College of Medical Genetics and the American College of Obstetricians and Gynecologists have recommended that individuals of AJ descent undergo carrier screening (and genetic counseling as necessary) for Tay Sachs disease, Canavan disease, familial dysautonomia, mucolipidosis IV, Niemann-Pick disease type A, Fanconi anemia type C, Bloom syndrome, and Gaucher disease. About a third of the Ashkenazi Jews in the New York City area carry at least one of the 16 primarily Jewish genetic diseases for which testing was available in 2010 [1].

Carrier frequencies for conditions appearing at relatively high frequency in Ashkenazi Jews are shown below, compiled from different sources including [2],[3] and [4]:

Medical Condition / Topic	Carrier Frequency, 1 in	Incidence, 1 in
Bloom syndrome	134	40000
Canavan disease	55	13000
Cystic fibrosis	23	4000
Dihydrolipoamide dehydrogenase deficiency	107	46000
Familial dysautonomia	31	3700
Familial hyperinsulinism	68	7800
Fanconi anemia group C	100	40000
Gaucher disease	15	855
Glycogen storage disease type 1A	64	20000
Joubert syndrome 2	90	40000
Maple Syrup Urine Disease	97	40000
Mucolipidosis type IV	90	40000
Nemaline myopathy	168	50000
Niemann-Pick disease type A/B	115	40000
Spinal muscular atrophy	67	10000
Tay-Sachs disease	27	3600
Usher syndrome type 1F	147	31000
Usher syndrome type III	120	57000
Walker-Warburg syndrome	150	90000