Because most Amish people descend from the families of the 200 founding members from the 18th century, they are at a greater risk of developing genetic disorders due to inbreeding. They also have a higher incidence of infant mortality.
However, the Amish consider these childhood deaths as well as disorders to be “Gottes Wille” (God’s will). They also refuse to be genetically tested prior to marriage.
These disorders include Angelman syndrome, dwarfism, and different metabolic disorders, as well as a rare distribution of blood types. Some of these conditions are quite unique and uncommon and are serious enough to determine a growth rate of mortality among Amish children.