Chédiak-Higashi syndrome
Autosomal recessive.
● Disordered coalescence of lysosomal granules Responsible gene found at
1q42-45. The encoded protein (LYST) has structural features homologous to a
vacuolar sorting protein.
● Impaired functions are :
a) Decreased neutrophilic chemotaxis, degranulation, and bactericidal activity;
b) platelet storage pool defect; impaired NK function; failure to disperse
melanosomes
● Clinical features :
a) Neutropenia, recurrent pyogenic infections
b) Propensity for the development of marked hepatosplenomegaly in the
accelerated phase.
c) Partial albinism:
d) Defects in myelopoiesis result in neutropenia.
e) Advanced disease is characterized by lymphocytic tissue infiltrates and
pancytopenia.