What are "Jewish" genetic disorders?
This term describes a group of conditions which are unusually common among Jews of Ashkenazi (Central and Eastern European) descent. Although these diseases can affect Sephardi Jews and non-Jews, they appear in Ashkenazi Jews more often — as much as 20 to 100 times more frequently. There is no set panel of Jewish genetic disorders, and different labs screen for a different number of them. The most current recommendation comes from the American College of Medical Genetics (ACMG), and suggests screening for nine specific disorders.

Why are certain disorders more common among Ashkenazi Jews?
Scientists believe that certain disorders became more common among Ashkenazi Jews because of at least two processes: the "founder effect" and genetic drift.

"Founder effect" refers to the chance presence of these genes among the "founders" or ancestors who immigrated to Eastern Europe at the time of the Diaspora (70 C.E.). Prior to this time we presume that these disorders were no more common among Jews than among any other people.

Genetic drift refers to the increase in frequency of the genes for these disorders in this group, as a result of chance. Because Jews tend to not marry outside of their faith and community, the relatively high frequency of these genes among Jews did not pass into other communities, nor was the frequency lessened by the introduction of other genes from outside the Ashkenazi Jewish community.

Visit Jews and Increased Risk for a more in-depth discussion of these issues. Community leaders may find What Rabbis Needs to Know helpful.

What are the Jewish genetic disorders?
There is no "official" list of these conditions. They include disorders which directly result from mutated genes (Mendelian disorders) and disorders which result from the combination of specific genes (disease predisposition genes) plus other factors.

Mendelian disorders
Bloom’s syndrome
Canavan disease
Cystic fibrosis
Dihydrolipoamide dehydrogenase deficiency
Factor XI deficiency
Familial dysautonomia (Riley-Day syndrome)
Familial hyperinsulinism
Fanconi anemia
Gaucher disease
Glycogen storage disease type IA
Maple syrup urine disease
Mucolipidosis IV
Nemaline myopathy
Niemann-Pick disease
Nonclassical adrenal hyperplasia
Nonsyndromic hearing loss
Tay-Sachs disease
Torsion dystonia
Usher syndrome III
Usher syndrome IF

Cancer predisposition syndromes
Hereditary breast and ovarian cancer (BRCA1 and BRCA2)
Familial colon cancer

Are there Sephardi Jewish genetic diseases?
Yes, but they differ based on country of origin. Some examples include beta thalassemia (Iran/Iraq), cystic fibrosis (N. Africa/Iraq/Yemen), cystinuria (Libya), familial Mediterranean fever (Iran/Iraq/N.Africa), G6PD deficiency (Iran/Iraq/Syria), glycogen storage disease type IIIa, hereditary inclusion body myopathy (Iran), limb girdle muscular dystrophy type 2B (Libya), megalencephalic leukoencephalopathy(Libya), oculocutaneous albinism (Libya), and Wolman disease (Iran).

What other groups of people have specific genetic diseases?
It is estimated that we all carry 6 to 8 disease-producing genes which would be harmful if passed on to our children by both parents. Many other racial and ethnic groups have “their own” genetic disorders – disorders which are not unique to the group, but which are more common in the group.