The Amish and Mennonite populations represent outstanding communities for the study of genetic disease for a number of reasons. There is a high degree of inbreeding, resulting in a high frequency of recessive disorders, many of which are seen rarely or are unknown outside of this population. Extensive genealogical records are available, and the average family size is large. This proposal includes a number of collaborators who have had extremely close, extensive interaction with the Lancaster County Amish over the past decade; their relationships with the community are invaluable to the success of this project. We have had substantial success with this research over the past seven years, leading to the discovery of the molecular etiology of four human diseases and the establishment of a useful database and tools for genealogical analysis. We propose to continue this line of research to further characterize these disorders and identify additional ones, as well as enlarging a computerized Anabaptist genealogy.
