Almost every ethnic or demographic group has higher rates of certain genetic diseases than the general population. There are a number of genetic conditions that are relatively unknown, but terribly debilitating – and all occur most frequently in people with Ashkenazi Jewish ancestry:
How is it possible that certain diseases are more common within the Ashkenazi Jewish population? One possible explanation is something called the “Founder effect.” For centuries, political and religious factors ensured that Ashkenazi Jews remained genetically isolated (i.e. no intermarriage). The Founder effect is based on the idea that even if just a few of the original founders of the Ashkenazi Jewish population had a gene change (or mutation), that change would then be passed on for generations as a result of this genetic isolation.
For example, 1 in 100 people of Eastern European Ashkenazi ancestry are carriers of Bloom’s syndrome, in comparison with 1 in 6,330,000 people in the general population. The higher likelihood of Ashkenazi Jews to be carriers of Bloom’s syndrome (and the other genetic disorders mentioned above) demonstrates the important of carrier screening. Carrier screening allows couples to determine the likelihood that they will have an affected child by finding out if they carry a gene change which could cause one of these disorders.
In order for a child to be affected by one of these recessive genetic disorders, both parents must be carriers of the disease (A carrier is someone with one “normal” gene and one gene change). When two carriers have a child, that child has a 1 in 4 chance of inheriting two gene changes, and therefore, the disease.
Carrier screening is relatively simple and usually requires no more than a blood draw or a cheek swab.