Familial alopecia areata and chronic thrombocytopenia.

Alopecia areata (AA) has a strong hereditary component and is associated with a number of other autoimmune diseases. There is no established relationship between AA and any of the congenital thrombocytopenias. We report a family in which multiple members are affected with AA and with a hereditary thrombocytopenia, most consistent with pseudo-von Willebrand disease. This raises the possibility of a genetic association between AA and one or more of the inherited thrombocytopenias, possibly both related to mutations in genes on chromosome 17.