Inherited defective platelet aggregation with arachidonate as the main expression of a defective metabolism of arachidonic acid

A disorder of platelet function was found in 7 members belonging to 3 generations of a family with a mild bleeding tendency. Only the platelet aggregation with arachidonate was deficient. Other inducers gave normal platelet responses. The metabolism of arachidonic acid by the platelets could be investigated in one proband. A defect suggesting a cyclo-oxygenase deficiency was found. The results indicate that the metabolites of arachidonate cannot be directly involved in the transmission of stimuli causing platelet aggregation, at least not under all conditions.