Griscelli syndrome 2
An über rare autosomal recessive disorder (OMIM:607624) characterised by pigmentary dilution of skin and hair, pigment clumping in hair shafts, and accumulation of melanosomes in melanocytes. GS2 patients also develop uncontrolled T-cell and macrophage activation (formally known as haemophagocytic syndrome), which leads to death in absence of bone marrow transplantation, and to neurological impairment in some patients.
Molecular pathology Defects in RAB27A, which encodes a small membrane-bound GTPase required for granule maturation, docking and priming at the immunologic synapse, that may be involved in protein transport and signal transduction, cause Griscelli syndrome 2.
Synonyms Griscelli-Prunieras syndrome (in part), Griscelli syndrome with haemophagocytic syndrome, PAID syndrome partical albinism and immunodeficiency