Page Contents
OVERVIEW
This page is dedicated to organizing various examples of standardized exam questions whose topic is maple syrup urine disease (MSUD). While this may seem a odd practice, it is useful to see multiple examples of how MSUD will be characterized on standardized exams (namely the boards and the shelf exams). This page is not meant to be used as a traditional question bank (as all of the answers will be the same), however seeing the classic “test” characterization for a topic is quite valuable.
KEY CHARACTERISTICS OF THIS CONDITION (ON EXAMS)
When it comes to standardized exams, each topic has its own “code” marked by key buzzwords, lab findings, clues, etc. If you are well versed in this code you will be able to more quickly identify the condition that is being discussed, and get the right answer on the exam you are taking. Below is the “code” for MSUD.
- Signs of neurotoxicity: Seizures, irritability, lethargy, poor feeding
- Sweet smelling urine: this is a VERY specific clue that points to this condition.
QUESTION EXAMPLES
Question # 1
Explanation # 1
Question # 2
Explanation # 2
TESTABLE FACTS ABOUT THIS TOPIC (BEYOND ITS IDENTIFICATION)
Many questions on standardized exams go beyond simply recognizing the underlying topic. Often there are specific testable facts regarding some aspect of the topic’s pathophysiology/management/clinical implications that are commonly asked. Some of these are listed below:
- Cause: the defective breakdown of branched chain amino acids
- Enzyme responsible: branched-chain alpha-keotacid dehydrogenase (BCKDC). It is mutated in this condition.
- Cofactors for enzyme: thiamine is required
- Branched chain amino acids: leucine, isoleucine, and valine
- Inheritance pattern: autosomal recessive
- Cause of sweet urine: metabolite of isoleucine is responsible
- Treatment:
- Lifelong dietary restriction: avoidance of branched chain amino acids
- High dose thiamine may be beneficial to some patients
Page Updated: 05.02.2017