Chediak-Higashi syndrome

Chédiak-Higashi syndrome is an inherited (AR inheritance) disease caused by a mutation in the LYST gene (lysosomal rafficking regulator, localization 1q42.1 – q42.2). As the name suggests, the product of that gene is involved in the formation of lysosomes, mainly affecting the composition of their contents, which is defective in the case of a gene mutation. Both lysosomes and melanosomes are enlarged (sometimes to gigantic proportions) and dysmorphic.

Defective granule composition of neutrophilic granulocytes causes inefficiency of the phagocytic mechanism, which causes increased susceptibility to certain infections, especially bacterial (mainly Staphyloccocus aureus) and fungal infections. Abnormal granules are also responsible for defects in T-lymphocytes and NK cells. In advanced syndrome, tissue infiltration may occur due to lymphoproliferative disorders.

Affected individuals have reduced pigmentation - the skin is light and the hair has a light to silver tinge. They also suffer from photophobia and increased sensitivity to sunlight due to defective melanocyte granules.