WBR0986
| Author | [[PageAuthor::Rim Halaby, M.D. [1]]] |
|---|---|
| Exam Type | ExamType::USMLE Step 1 |
| Main Category | MainCategory::Biochemistry |
| Sub Category | SubCategory::General Principles |
| Prompt | [[Prompt::A 3 year old girl is noted to have progressively worsening hypotonia associated with two previous episodes of acute self resolving ataxia. The girl is on the lower limit of growth in height and weight with a noticeable developmental delay. Laboratory results are significant for mild metabolic acidosis. A skeletal muscle biopsy reveals immunochemical evidence of E1 subunit deficiency in the pyruvate dehydrogenase complex. The parents are genetically counseled and advised to provide the girl with a strict diet. Abundance in which of the following amino acids is recommended in this girl's condition?]] |
| Answer A | AnswerA:: |
| Answer A Explanation | AnswerAExp:: |
| Answer B | AnswerB:: |
| Answer B Explanation | AnswerBExp:: |
| Answer C | AnswerC:: |
| Answer C Explanation | AnswerCExp:: |
| Answer D | AnswerD:: |
| Answer D Explanation | AnswerDExp:: |
| Answer E | AnswerE::Lysine |
| Answer E Explanation | [[AnswerEExp::Lysine and leucine are strictly ketogenic amino acids that do not require pyruvate dehydrogenase for their metabolism. A patient with pyruvate dehydrogenase is required to have a strict ketogenic diet rich in fat and the amino acids leucine and lysine.]] |
| Right Answer | RightAnswer::E |
| Explanation | [[Explanation::Reference:
Bindoff, L. A., Birch-Machin, M. A., Farnsworth, L., Gardner-Medwin, D., Lindsay, J. G., Turnbull, D. M. Familial intermittent ataxia due to a defect of the E1 component of pyruvate dehydrogenase complex. J. Neurol. Sci. 93: 311-318, 1989. |
| Approved | Approved::No |
| Keyword | WBRKeyword::Pyruvate dehydrogenase, WBRKeyword::lysine, WBRKeyword::ketongenic |
| Linked Question | Linked:: |
| Order in Linked Questions | LinkedOrder:: |