Familial myeloproliferative disease. Hematological and cytogenetic studies.

A family is described in which a form of myeloproliferative disease involving the megakaryocytic cell line occurs in three generations, resulting in thrombocytosis in several members. An autosomal dominant transmission with variable penetrance is proposed, based on the distribution of involved members in the pedigree. Two family members appeared to have an abnormal chromosome 7, which is frequently observed in patients with hematological disorders. It is our opinion that the chromosomal aberration is primarily related to the mutagenicity of the cytostatic treatment, although a primary defect cannot be fully excluded.