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 immunodeficiency. Two different gene loci are responsible for this rare, autosomal recessive disease: the myosin Va gene and the RAB27A gene. As recently reported, only patients with mutations of the RAB27A gene suffer from immunodeficiency 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, valuable time may be lost by searching for an HLA-identical unrelated donor. We report the first peripheral blood stem cell transplant (PBSCT) with T cell depletion in a 6-month-old girl with Griscelli syndrome, and a deletion of the RAB27A gene. The donor was her phenotypically HLA-identical mother. Conditioning included busulfan, VP16 and cyclophosphamide. The patient was transfused with 15.4 x 10(6)CD34-positive cells/kg and 17.6 x 10(3) CD3-positive cells/kg recipient weight. Three months after the transplant, a curable lymphoproliferative syndrome occurred. 26 months after the transplant, the patient is doing well with stable mixed chimerism (52% donor cells).