Familial leukemia and aplastic anemia associated with monosomy 7.

A kindred is described in which eight of 14 patients in one generation had acute nonlymphocytic leukemia or aplastic anemia either alone or terminating in acute nonlymphocytic leukemia. The proband and two siblings in one branch of this kindred presented with aplastic anemia, whereas acute nonlymphocytic leukemia was the presenting feature in the other two branches. Karyotypic evolution from a normal karyotype to monosomy 7 was demonstrated in the proband, and group C monosomy was seen in two other patients. The proband's serum sample inhibited in vitro growth of normal bone marrow colonies. The occurrence of hematologic disease in this kindred appears to be the result of a maternally transmitted trait, and persons younger than 30 years of age appear to have the highest risk of hematologic disease.