NBEAL2 expression is also required for the development of thrombocytes in zebrafish.In Japan, GPS was found in 24 affected patients in a single family. There was at least 1 instance of male-to-male transmission, consistent with autosomal dominant inheritance.A study reported of 14 families with GPS, 11 families had clear autosomal recessive inheritance. This was evidenced by consanguinity or multiple affected siblings with unaffected parents. The families had various backgrounds, including Bedouin, Turkish, Mennonite, French, German, Somali, African American, and mixed Northern and Southern European.GPS is characterized by "thrombocytopenia, and abnormally large agranular platelets in peripheral blood smears." The defect in GPS is the failure of megakaryocytes to package secretory proteins into alpha-granules. Patients with the GPS are affected by mild to moderate bleeding tendencies. Usually these are not major bleeds but there has been some life-threatening cases. Affected women will tend to have heavy, irregular periods. Myelofibrosis is a condition that usually comes with GPS. Diagnosis
GPS is diagnosed based on clinical findings and requires demonstration of absence or marked reduction of alpha-granules by electron microscopy (EM). High serum vitamin B12 levels are common in patients diagnosed with GPS. Bone marrow sampling, though not required for diagnosis of GPS, might be necessary to evaluate myelofibrosis occurring in GPS and to exclude other disorders. Management
There is no specific treatment  for GPS, but it can be managed by anticipating and preventing the risks of bleeding. The treatment options include desmopressin. Splenectomy can be used to increase the platelet counts in those whose platelet counts decrease to approximately 30,000/microliter.
Prognosis is generally good early in life when thrombocytopenia is mild. Epidemiology
Currently, only 60 cases have been recorded worldwide. While the prevalence of this syndrome is not known, it was found that it affects males and females equally. See also
Pseudo gray platelet syndrome
Giant platelet disorder

References
External links

Gray platelet syndrome at NIHs Office of Rare Diseases