The York platelet syndrome: a fourth case with unusual pathologic features.

The present report describes a fourth patient with platelet pathological features identical to those found in the first three cases with the York platelet syndrome (YPS), as well as other findings that suggest he may be a variant. His platelets contain the same giant opaque and target organelles found earlier, as well as enlarged organelles with a gray appearing matrix. It is possible that the giant structures have the same source, but are at different stages of development. The fourth patient has platelet pathology suggestive of other thrombocyte disorders. He has many large platelets and normal sized thrombocytes nearly devoid of alpha granules. As a result, he was originally thought to have the gray platelet syndrome. He also has significant numbers of platelets attached to platelets and platelets in platelets as seen in patients with the X-linked GATA-1 mutation. Some of the fourth YPS patient's platelets contained massive alpha granules suggesting the possibility of the Paris Trousseau Jacobson Syndrome. Yet, none of these other platelet disorders had giant dense organelles like those found in YPS thrombocytes. As a result, it is reasonable to include this child with the other three, and diagnose him as a patient with the YPS.