Immunology USMLE Step 1 Practice Question
A 5 year old girl is evaluated for recurrent pyogenic infections and progressive difficulty walking. Her parents report that she bruises easily and that her hair and skin have always been unusually light. Peripheral smear shows giant granules in neutrophils. Which of the following cellular defects is most likely present?
Answer choices
- AAbsent respiratory burst due to NADPH oxidase deficiency
- BDeficiency of terminal complement components
- CDefective thymic development due to 22q11 deletion
- DFailure of class switching due to CD40 ligand deficiency
- EDefective phagolysosome fusion due to microtubule dysfunctionCorrect answer
- FGriscelli syndrome type 2 (RAB27A mutation)
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