Griscelli Syndrome is a rare immunodeficiency which can be fatal if a hematopoietic stem cell transplant is not performed.
Genes implicated: MYO5A (Type 1), RAB27A (Type 2)), MLPH (Type 3)
Inheritance: autosomal recessive
Clinical features:
(1) reduced skin pigmentation (partial albinism)
(2) silvery gray hair
(3) immunodeficiency
(4) hemophagocytic lymphohistiocytosis (HLH) with pancytopenia and hepatosplenomegaly
(5) neurologic involvement (seizures, other)
(6) recurrent chest infections
Examination of the hair shaft:
(1) large melanin granules primarily in the medullary zone (gigantic melanocytosis)
(2) under polarized light the shaft is bright and monotonously white
The differential diagnosis includes the Chediak-Higashi Syndrome.
