A study of platelet function and morphology in a new family with May-Hegglin anomaly.

A new family with May-Hegglin anomaly is presented. 9 patients were found to be affected, namely to present thrombocytopenia, giant platelets, and leukocytes inclusion bodies. A mild to moderate hemorrhagic diathesis was present in 8 patients (easy bruising, excessive bleeding after tooth extraction, menomethrorrhagia). One patient was asymptomatic. The bleeding tendency seemed to be relatively more pronounced in those patients who have larger platelets. Bleeding time was slightly prolonged in 4 of the affected patients. Platelet aggregation to Ristocetin and serotonin release was normal; on the contrary, platelet adhesiveness was slightly decreased in all patients. Plasma Btg was investigated in 7 patients, found to be normal in 5 and elevated in 2. Platelet Btg was found to be increased in all patients investigated. The ratio between Btg and platelet number was elevated in every instance. The circulating platelet mass (Btg platelet mass microgram/ml) was investigated in 7 patients, found normal in two and decreased in the remaining three. The disorder is transmitted as an autosomal dominant trait but there seems to be a variable phenotypic expression from one patient to the other.