Morphological and biochemical confirmation of gray platelet syndrome in two siblings

A case report is presented of gray platelet syndrome in siblings. The absence of platelet alpha-granules in these patients was confirmed by electron microscopy and by analysis of the platelet protein profile using SDS-polyacrylamide gel electrophoresis. This was further confirmed by quantitation of individual alpha-granule protein constituents. The results in these two patients are compared with those of the four reported patients with this syndrome.