[Griscelli syndrome type 3: A new case]. / Syndrome de Griscelli de type 3 : un nouveau cas.

ABSTRACT

INTRODUCTION: Griscelli syndrome (GS) is a rare autosomal-recessive genetic disease characterized by hypopigmentation of skin and hair. We report a case of GS type 3 with late diagnosis. OBSERVATION A 31-year-old female patient had presented depigmentation of the hair and eyebrows as well as diffuse skin hypopigmentation during childhood. Microscopic analysis of a hair shaft revealed irregularly distributed clumps of melanin. DNA sequencing showed a homozygous C103T (R35W) transition in exon 1 of MLPH, confirming Griscelli syndrome type 3. DISCUSSION: Three clinical phenotypes of GS have been described based on the underlying genetic defect. GS type 1 and 2 are associated respectively with a central nervous system dysfunction and an immune defect. GS type 3 is an isolated cutaneous form. Diagnosis is confirmed on microscopic examination of hair shafts. 15 cases of GS type 3 have been reported 9 in males and 6 in females. Mean age at diagnosis is around 12 years. Nine of the reported patients were of Arab origin, four of Turkish origin, and one of Indian origin. R35W mutation was described in 9 cases and E98X and R35Q mutations were each found in one case. CONCLUSION: GS should be suspected in patients presenting gray silvery hair, particularly when these patients are of Arab or Turkish origin.