cartilage-hair hypoplasia [L, cartilago + AS, haer + Gk, hypo, under, plasis, forming] , a genetic disorder characterized by dwarfism caused by hypoplasia of the cartilage; multiple skeletal abnormalities; and excessively sparse, short, fine, brittle hair that is usually light colored. It is inherited as an autosomal-recessive trait. The condition is found primarily among Amish people in the United States and Canada.