WBR0290

Author	[[PageAuthor::Ogheneochuko Ajari, MB.BS, MS [1](Reviewed by Serge Korjian)]]
Exam Type	ExamType::USMLE Step 1
Main Category	MainCategory::Biochemistry, MainCategory::Pathology
Sub Category	SubCategory::Gastrointestinal, SubCategory::Neurology
Prompt	[[Prompt::A 10-year-old girl is brought to the emergency department for complaints of fever, recurrent watery diarrhea, and abdominal pain. Her family emigrated from Romania 1 year ago, and the child has not received any medical care since. The mother reports that her child has had a history of recurrent sinusitis and multiple hospitalizations for pneumonia since the age of 4. On physical examination, you notice a sick looking girl with a fair complexion, sparse light blonde hair, and blue eyes. You also note several aphthous ulcers, mild hepatosplenomegaly, and decreased pin-prick sensation in both lower extremities. Which of the following defects is most likely to be responsible for this patient's condition?]]
Answer A	AnswerA::Dynein arm defect
Answer A Explanation	AnswerAExp::
Answer B	AnswerB::Lysosomal degranulation defect
Answer B Explanation	AnswerBExp::
Answer C	AnswerC::Type 1 collagen defect
Answer C Explanation	AnswerCExp::
Answer D	AnswerD::Kinesin arm defect
Answer D Explanation	AnswerDExp::
Answer E	AnswerE::Defect in fibrillin
Answer E Explanation	AnswerEExp::
Right Answer	RightAnswer::B
Explanation	[[Explanation:: Educational Objective: Chediak-Higashi syndrome is a rare autosomal recessive immunodeficiency disorder caused by a defect in lysosomal degranulation and phagolysosome formation. It presents with partial albinism, peripheral neuropathy, and pyogenic sinopulmonary infections. Other findings include lymphadenopathy, hepatosplenomegaly, and mucosal ulcerations. References: Kaplan J, De Domenico I, Ward DM. Chediak-Higashi syndrome. Curr Opin Hematol. Jan 2008;15(1):22-9.]]
Approved	Approved::Yes
Keyword	WBRKeyword::Sinopulmonary infections, WBRKeyword::Peripheral neuropathy, WBRKeyword::Partial albinism, WBRKeyword::Pyogenic infections, WBRKeyword::Chediak-Higashi syndrome, WBRKeyword::Phagolysosome, WBRKeyword::Lysosomal degranulation, WBRKeyword::Congenital immunodeficiency, WBRKeyword::Immunodeficiency syndromes
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