<unk>  <unk> , or platelet alpha-granule deficiency, is a rare congenital autosomal recessive bleeding disorder caused by a reduction or absence of alpha-granules in blood platelets, and the release of proteins normally contained in these granules into the marrow, causing myelofibrosis.<unk>  is primarily inherited in an autosomal recessive manner, and the gene that is mutated in<unk>  has recently been mapped to chromosome 3p and identified as NBEAL2. NBEAL2 encodes a protein containing a BEACH domain that is predicted to be involved in vesicular trafficking.  It is expressed in platelets and megakaryocytes and is required for the development of platelet alpha-granules. NBEAL2 expression is also required for the development of thrombocytes in zebrafish.<unk>  is characterized by "thrombocytopenia, and abnormally large agranular platelets in peripheral blood smears." The defect in<unk>  is the failure of megakaryocytes to package secretory proteins into alpha-granules. Patients with the<unk>  are affected by mild to moderate bleeding tendencies.
Grey platelet syndrome
Sticky platelet syndrome
Pseudo gray platelet syndrome
Bernard-Soulier syndrome
Glanzmann's thrombasthenia
Von Willebrand disease
Familial dysfibrinogenemia
Giant platelet disorder