An 8-month-old child presents with a silver sheen to her hair, seizures, hepatosplenomegaly, lymphadenopathy, pancytopenia, recurrent Staph aureus skin infections, and enlarged granules noted within neutrophils on peripheral smear. Which of the following gene defects is most likely to be identified?

Chediak-Higashi Syndrome Autosomal recessive Lysosomal transpo protein (LYST/CHS1) gene defect, vesicular trafficking defect Incomplete oculocutaneous albinism Decreased chemotaxis of neutrophils, decreased antibody dependent cellular cytotoxicity, presence of giant peroxidase-positive lysosomal granules in peripheral blood granulocytes; results in severe infections Clinical findings;- Childhood CHS: accelerated phase: early onset with fever, anemia, and neutropenia . Adolescent CHS: severe infections in early childhood, no accelerated phase Adult CHS: mild form, develop progressive and fatal neurologic dysfunction in middle age Eyes: ocular hypopigmentation causes photophobia, nystagmus, and strabismus Hair: silvery sheen Skin: pale, deep ulcerations, petechiae, bruising, and gingival bleeding Neurologic: weakness, ataxia, sensory deficits, and progressive neurodegeneration Lymphoma: "accelerated phase" precipitated by viruses (e.g., Epstein-Barr virus); widespread infiltration of viscera Other: hepatosplenomegaly, lymphadenopathy, pancytopenia, pseudomembrane, and sloughing of the buccal mucosa . Laboratory findings:- Giant intracellular granules in circulating neutrophils, melanocytes, neurons, and renal tubular cells * Granules form secondary to delayed disorder of lysosomal enzymes from cells. Treatment:- Bone marrow (or stem cell) transplant, acyclovir, interleukin, gamma globulin, vincristine, prednisone, and prophylactic antibiotics. Ref:- Dermatology pictorial review by ASRA ALI; pg num:-170