WBR0486
| Author | [[PageAuthor::Rim Halaby, M.D. [1], Alison Leibowitz [2] (Reviewed by Alison Leibowitz)]] |
|---|---|
| Exam Type | ExamType::USMLE Step 1 |
| Main Category | MainCategory::Pathophysiology, MainCategory::Pharmacology |
| Sub Category | SubCategory::Hematology |
| Prompt | [[Prompt::A 1-year-old male is brought to the pediatrics outpatient clinic for a four week duration of pallor and excessive sleepiness. His mother reports normal development and feeding habits and physical exam is significant for hepatomegaly and marked pallor. Blood tests demonstrate a hemoglobin level of 7.2 g/dL with microcytosis and anisocytosis. Futher testing reveals a mutation in the ALAS2 gene. Which of the following treatments is most appropriate for this patient?]] |
| Answer A | AnswerA::Chronic transfusions |
| Answer A Explanation | [[AnswerAExp::Chronic transfusions are frequently used to treat patients with thalassemia major or other bone marrow failure syndromes.]] |
| Answer B | AnswerB::Deferioxamine |
| Answer B Explanation | [[AnswerBExp::Deferioxamine is frequently used in the treatment of iron overload following chronic transfusions. Although sideroblastic anemia is associated with iron overload, iron chelation is not the first line of therapy.]] |
| Answer C | AnswerC::Pyridoxine |
| Answer C Explanation | AnswerCExp::See explanation. |
| Answer D | AnswerD::Folic Acid and Vitamin B12 |
| Answer D Explanation | [[AnswerDExp::Folic Acid and Vitamin B12 are frequently administered to treat megaloblastic anemia.]] |
| Answer E | AnswerE::Iron replacement |
| Answer E Explanation | [[AnswerEExp::Iron replacement is frequently used to treat patients with iron deficiency anemia.]] |
| Right Answer | RightAnswer::C |
| Explanation | [[Explanation::Sideroblastic anemia is an inherited disease in which the bone marrow produces ringed sideroblasts, due to defective hemoglobin synthesis and iron accumulation. Most frequently, sideroblastic anemia is an X-linked disease. The disease manifests due to a deficiency in ALA synthase, the rate limiting step in heme synthesis, secondary to a mutation in the ALAS2 gene. This decrease in heme synthesis leads to an accumulation of non-heme iron around red blood cells, resulting in a characteristic ringed sideroblasts appearance. Sideroblastic anemia is usually treated with pyridoxine (vitamin B6), which is a cofactor in the reaction catalyzed by ALA synthase. Educational Objective: Sideroblastic anemia is frequently treated with pyridoxine (vitamin B6), a cofactor in the reaction catalyzed by ALA synthase. |
| Approved | Approved::Yes |
| Keyword | WBRKeyword::Sideroblastic anemia, WBRKeyword::Pyridoxine, WBRKeyword::Vitamin B6, WBRKeyword::anemia, WBRKeyword::genetics, WBRKeyword::X-linked, WBRKeyword::pattern of inheritance, WBRKeyword::inheritance, WBRKeyword::genome, WBRKeyword::hemoglobin synthesis, WBRKeyword::pallor |
| Linked Question | Linked:: |
| Order in Linked Questions | LinkedOrder:: |