Griscelli Syndrome Type 2 Revealed by Macrophage Activation Syndrome: Two Cases From the Same Family.

Griscelli syndrome type 2 is a rare autosomal recessive disorder caused by mutations in the RAB27A gene. It is characterized by partial albinism, a silvery sheen of the hair, and an immune deficiency. We report cases of two siblings, a seven-year-old boy and his 10-year-old sister, who were admitted to the emergency department with sepsis complicated by macrophage activation syndrome. Their clinical course was rapidly unfavorable. The diagnosis of Griscelli syndrome type 2 was made in the light of a combination of clinical and biological arguments: oculocutaneous hypopigmentation, silvery sheen of the hair, the absence of psychomotor delay, the occurrence of a macrophage activation syndrome following an infection, and especially the pathognomonic appearance on microscopic examination of a hair sample. The absence of giant granulations in the nucleated cells made it possible to eliminate Chediak-Higashi syndrome. Griscelli syndrome type 2 should be considered in children presenting with hypopigmentation, silvery hair, and immune dysregulation, particularly when complicated by macrophage activation syndrome.