USMLE-Rx Step 1 Qmax Challenge #1384

- September 12, 2017

Check out today’s Step 1 Qmax Question Challenge.

Know the answer? Post it below! Don’t forget to check back for an update with the correct answer and explanation (we’ll post it in the comments section below).

usmle-rx-step-1-qmax-challenge-1384 A 2-year-old boy presents to his pediatrician with hepatosplenomegaly, failure to thrive, and progressive central nervous system deterioration. On ophthalmoscopic exam a cherry-red macula is noted. A bone marrow biopsy specimen is shown in the image. The pediatrician suspects that the boy will die by 3 years of age.

Which of the following is the function of the metabolic enzyme deficient in this patient?

A. Converts ceramide trihexoside to lactosyl cerebroside
B. Converts galactocerebroside to cerebroside
C. Converts ganglioside M2 to ganglioside M3
D. Converts glucocerebroside to ceramide
E. Converts sphingomyelin to ceramide

———————–

Want to know the ‘bottom line?’ Purchase a USMLE-Rx Subscription and get many more features, more questions, and passages from First Aid, including images, references, and other facts relevant to this question.

This practice question is an actual question from the USMLE-Rx Step 1 test bank. For more USMLE Step 1 prep, subscribe to our Flash Facts and Step 1 Express video series. Score the best deal on all three products with USMLE-Rx 360 Step 1.