The Amish, formally the Old Order Amish, are a group of traditionalist Anabaptist Christian church fellowships with Swiss German and Alsatian origins. They are closely related to Mennonite churches, a separate Anabaptist denomination. Blood group studies in two Old Order Amish isolates support previous evidence for genetic differences in the two groups. The more completely studied Amish community, that of Lancaster Co., Pa., revealed higher A and lower O phenotype frequencies than found in the Amish of Holmes Co., Ohio. In both groups, about one-fourth of individuals are Rh negative. Three blood group genes (Kell-positive, CDue and CDE) are present in low frequency in the Lancaster Amish, and pedigree studies identified individuals who may have introduced them to the Amish. … Continue reading 25% of the Amish are Rh-