Gray platelet syndrome

Gray platelet syndrome, or platelet alpha-granule deficiency, is a rare congenital bleeding disorder caused by a reduction or absence of alpha-granules in blood platelets. The name comes from the gray appearance of the platelets on blood films. It is usually inherited in an autosomal recessive way through mutations in the NBEAL2 gene, which is needed for platelets and megakaryocytes to develop alpha-granules, although a Japanese family with autosomal dominant inheritance has been reported. Signs usually arise at birth or in childhood and include low platelet count, easy bruising, nosebleeds, heavy menstrual bleeding in women, and myelofibrosis that can enlarge the spleen. Diagnosis needs electron microscopy showing absent alpha-granules. There is no specific treatment, and bleeding is managed by prevention, desmopressin and sometimes splenectomy. Only about 60 cases have been recorded worldwide.