Griscelli syndrome: report of the first peripheral blood stem cell transplant and the role of mutations in the RAB27A gene as an indication for BMT

Griscelli syndrome is characterized by partial albinism with variable immun odeficiency. Two different gene loci are responsible for this rare, autosom al recessive disease: the myosin Va gene and the RAB27A gene. As recently r eported, only patients with mutations of the RAB27A gene suffer from immuno deficiency and hemophagocytic lymphohistiocytosis. Thus, only patients who suffer from the Griscelli syndrome with mutations of the RAB27A gene should receive BMT/PBSCT, which is the only curative therapy. Due to the risk of early relapse or severe infections, BMT/PBSCT should be carried out as soon as possible; if patients do not have HLA-identical family members, valuabl e time may be lost by searching for an HLA-identical unrelated donor. We re port the first peripheral blood stem cell transplant (PBSCT) with T cell de pletion in a 6-month-old girl with Griscelli syndrome, and a deletion of th e RAB27A gene. The donor was her phenotypically HLA-identical mother. Condi tioning included busulfan, VP16 and cyclophosphamide. The patient was trans fused with 15.4 x 10(6) CD34-positive cells/kg and 17.6 x 10(3) CD3-positiv e cells/kg recipient weight. Three months after the transplant, a curable l ymphoproliferative syndrome occurred. 26 months after the transplant, the p atient is doing well with stable mixed chimerism (52% donor cells).