Jewish Genetic Disorders are a group of conditions which are unusually common among Ashkenazi Jews -- Jews who have ancestors from Eastern and Central Europe. These same diseases can affect Sephardi Jews and non-Jews, but they afflict Ashkenazi Jews more often - as much as 20 to 100 times more frequently.

See more: http://judaism.about.com/od/health/a/geneticdisorder.htm