Polycythemia vera with Ph-1 chromosomes in two brothers.

I N A RECENT REVIEW of the clinical and epidemiologic aspects of polycythemia, Modan’ discussed familial polycythemia, which was first reported in 19072 and in several reviews subsequently.3 5 As more sophisticated diagnostic technics have become available, familial polycythemia has been recognized to be a clinical entity, distinct from polycythemia rubra vera (PRV) in its clinical, hematologic and prognostic aspects.1’6 It may be a subgroup of benign erythrocytosis.’ Although the erythrocyte count, hemoglobin, and blood volume are elevated and splenomegaly may be present in the familial variant,1 the total and differential white blood cell and platelet counts are normal and there are no adverse effects exhibited by the affected children.6 Modan accepts only two reports5’7 in the literature dealing with familial polycythemia as representing unequivocal examples of familial PRy.’ This report concerns two brothers with clinically and hematologically typical PRy : one diagnosed 22 years ago and treated on several occasions with p32 prior to the present study, and the other diagnosed recently with baseline studies, including the cytogenetic examinations, performed before therapy was started. Only phlebotomy had been performed prior to the cytogenetic studies in the latter. In contrast to previously reported variable and inconsistent chromosomal abnormalities in untreated and treated patients with PRy,8’20’24’ 33,40 both brothers presented the unusual combination of Philadelphia (Ph’) chromosomes in marrow cells and elevated leukocyte alkaline phosphatase ( LAP ) . Whether this represents a familial disease or the fortuitous occurrence of Ph1-positive polycythemia vera in two brothers cannot be ascertained from the available data.