Gray platelet syndrome

Gray platelet syndrome
Classification and external resources
ICD-10 D69.1
OMIM 139090
DiseasesDB 29160
MedlinePlus 000582

Gray platelet syndrome (GPS), or platelet alpha-granule deficiency,[1] 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.[2]

GPS is primarily inherited in an autosomal recessive manner, and the gene that is mutated in GPS has recently been mapped to chromosome 3p[3] and identified as NBEAL2.[4] 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.[5] NBEAL2 expression is also required for the development of thrombocytes in zebrafish.[6]

GPS is characterized by "thrombocytopenia, and abnormally large agranular platelets in peripheral blood smears."[7] 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.

See also

References

  1. Online 'Mendelian Inheritance in Man' (OMIM) 139090
  2. Nurden AT, Nurden P (2007). "The gray platelet syndrome: clinical spectrum of the disease". Blood Rev. 21 (1): 21–36. doi:10.1016/j.blre.2005.12.003. PMID 16442192.
  3. Gunay-Aygun M, Zivony-Elboum Y, Gumruk F et al. (December 2010). "Gray platelet syndrome: natural history of a large patient cohort and locus assignment to chromosome 3p". Blood 116 (23): 4990–5001. doi:10.1182/blood-2010-05-286534. PMC 3012593. PMID 20709904.
  4. Kahr WH, Hinckley J, Li L et al. (August 2011). "Mutations in NBEAL2, encoding a BEACH protein, cause gray platelet syndrome". Nat. Genet. 43 (8): 738–40. doi:10.1038/ng.884. PMID 21765413.
  5. Gunay-Aygun M, Falik-Zaccai TC, Vilboux T et al. (August 2011). "NBEAL2 is mutated in gray platelet syndrome and is required for biogenesis of platelet α-granules". Nat. Genet. 43 (8): 732–4. doi:10.1038/ng.883. PMC 3154019. PMID 21765412.
  6. Albers CA, Cvejic A, Favier R et al. (August 2011). "Exome sequencing identifies NBEAL2 as the causative gene for gray platelet syndrome". Nat. Genet. 43 (8): 735–7. doi:10.1038/ng.885. PMC 3428934. PMID 21765411.
  7. Jantunen E, Hänninen A, Naukkarinen A, Vornanen M, Lahtinen R (July 1994). "Gray platelet syndrome with splenomegaly and signs of extramedullary hematopoiesis: a case report with review of the literature". Am. J. Hematol. 46 (3): 218–24. doi:10.1002/ajh.2830460311. PMID 8192152.

External links