Résumé
Griscelli syndrome type 2 is a rare autosomal recessive disease caused by mutations in the RAB27A gene. It is characterized by pigmentary dilution of the skin and hair causing silvery gray hair, hemophagocytic lymphohistiocytosis and characteristic light microscopy findings in scalp hair shaft seen as large irregular clumps of pigment as opposed to the evenly distributed pigment along the hair shaft without any clumps. We describe a boy with classic features of Griscelli syndrome type 2 from Pakistan in whom a homozygous mutation in the RAB27A gene was identified that showed a single base substitution [c.598C>T] predicted to cause premature protein termination [p.Arg200[asterisk]]. We also present a clinical approach to silver blonde hair differentiating between the Griscelli syndrome types 1, 2 and 3, Chediak Hegashi Syndrome and Elejalde Syndrome