The May-Hegglin anomaly: platelet function, ultrastructure and chromosome studies.

T HE MAY-HEGCLIN ANOMALY is a rare hereditary condition characterized by giant platelets and D#{246}hle inclusion bodies in the granulocytes. May first described the anomaly in 1909,’ and in 1945 Hegglin described the condition in a man and his two sons.2 Subsequent reports have confirmed the familial nature with an autosomal dominant mode of inheritance.3 3 Although most persons with the May-Hegglin anomaly have no abnormal clinical manifestations, some have had a definite hemorrhagic tendency which would not he wholly accounted for by the degree of thrombocytopenia which they manifested. Detailed coagulation studies have been reported in only two instances.4’11 Three affected members of one family were found to have a moderate deficiency of platelet thromboplastic activity;4 electron microscopic observations of whole unsectioned platelets of one member of this family were interpreted as demonstrating abnormal viscous metamorphosis.14 We have recently had the opportunity to study a father and son with the May-Hegglin anomaly. The present report describes coagulation studies, particularly those of platelet function, as well as electron microscopic observations of platelet and granulocyte ultrastructure. Chromosomal studies are included as the only previous report of chromosome analysis in the May-Hegglin anomaly described a minor chromosomal abnormality.7