Griscelli syndrome

Griscelli syndrome is an autosomal recessive inherited form of partial albinism associated with an immune deficiency. The hair and skin are only slightly pigmented, while in the hair shaft are large pigment aggregates and in the melanocytes, the number of mature melanosomes is increased.

The causes are mutations in MYO5A (type 1), RAB27A (type 2) or in the MLPH gene (type 3). However, the syndrome is genetically heterogeneous.

Patients with a mutation in the RAB27A gene develop not only pigment abnormalities but also cytotoxic defects and a homozygotic syndrome as a result of uncontrolled activation of T lymphocytes and macrophages. Patients often die from the homozygous syndrome unless they receive a bone marrow transplant.

Affected individuals with a mutation in the MYO5A gene encoding myosin-VA, in addition to the pigmentation disorder, get primary neurological impairment that starts early.