A novel RAB27A mutation in a patient with Griscelli syndrome type 2.

Griscelli syndrome type 2 is a rare autosomal recessive primary immunodeficiency disease caused by a mutation in the RAB27A gene and characterized by oculocutaneous hypopigmentation and variable cellular immunodeficiency. We report the case of a 6-month-old infant with silvery hair, eyelashes, and eyebrows who was referred to our center because of fever and hepatosplenomegaly. Bone marrow studies indicated hemophagocytosis, whilst microscopic examination of the hair showed irregular agglomerations of pigment in hair shafts. Molecular analysis revealed a novel homozygous mutation in exon 5, namely, a single-base substitution (g.42996 A>G) leading to an amino acid change (S115G) and thus confirming the diagnosis of Griscelli syndrome type 2. Griscelli syndrome could be more common than thought, especially in regions with high rates of consanguinity. As the prognosis of disease is usually poor, prompt diagnosis and appropriate treatment are vital to avoid complications.