Familial thrombocytopenia associated with platelet autoantibodies and chromosome breakage.

An extended family is described in which three members had thrombocytopenia. These affected members had chromosomal changes resembling those found in Fanconi's anaemia, though they lacked the development defects associated with that syndrome. One had bone-marrow hypoplasia and died of squamous cell carcinoma of the mouth at the age of 27. In addition, all three had platelet autoantibodies not found in any other family members tested. There was no linkage between the thrombocytopenia and HLA groups. The nature of the association of thrombocytopenia, platelet autoantibodies and chromosomal abnormalities in this family remains doubtful.