The Platelet Defect Associated with Albinism

Abstract

S ummary . Investigations on the blood of two albino women with a haemostatic defect have revealed a specific abnormality of their platelets. This consists of an inability of the platelets to store adenine nucleotides in a metabolically inert form, and consequently of an impairment of the release reaction whereby normal platelets are induced to aggregate by agents, including collagen and thrombin, that act indirectly through the release of adenosine diphosphate ( ADP ). These patients' platelets also have a greatly impaired ability to take up and store 5‐hydroxytryptamine (5HT) and adrenaline. It is suggested that the haemostatic failure previously observed in association with albinism is a result of such a defect of storage and release of adenine nucleotides by the platelets. Investigations on seven other albinos without haemorrhagic symptoms have shown no abnormality of platelet aggregation or nucleotide storage.