Chediak-Higashi Syndrome is an autosomal recessive immunodeficiency, caused by defects in the LYST protein.
Defects in LYST, or lysosomal trafficking regulator protein, cause problems in vesicle transport, which most significantly impair phagosome-lysosome fusion. Due to defects in phacoytosis, patients are immunocompromised and present with recurrent pyogenic infections. Other clinical manifestations include progressive neurologic dysfunction, and albinism.
On blood smear, giant granules are observed in granulocytes, and a complication to look out for is infiltrative lymphohistiocytosis (overactive lymphocytes and histiocytes) with resulting pancytopenia.
Find this Chediak-Higashi Syndrome mnemonic and more Immunodeficiencies mnemonics among Pixorize's visual mnemonics for the USMLE Step 1.