Practice Exam-Biochemical Genetics

Biochemical Genetics

Pdf Summary

The document appears to be a practice exam for a course on Biochemical Genetics, authored by Claudia Barnett, focused on topics within Biochemical Genetics I and II. The exam includes multiple-choice questions with commentary and references provided for each question.<br /><br />One question addresses the genetic cause of Leigh Syndrome in infancy: if caused by a mitochondrial DNA (mtDNA) point mutation, the most common mutation is m.8993TG (MT-ATP6). However, the question discussing the general causes of Leigh Syndrome in infancy points out that the most common genetic cause is biallelic mutations in a nuclear gene.<br /><br />Another question pertains to the treatment of Maple Syrup Urine Disease (MSUD) during metabolic decompensation, advising against the administration of intravenous fluids at twice the maintenance rate in cases of hyponatremia due to risks of brain edema and potential death.<br /><br />A clinical scenario describes an 8-day-old infant who presents in a comatose state with characteristic symptoms including irritability, anorexia, opisthotonos, and apnea, and a distinctive sweet odor. The scenario likely depicts Maple Syrup Urine Disease, a condition notoriously detected by the sweet, maple syrup-like odor, leading to its diagnosis in the absence of newborn screening.<br /><br />The questions are part of a practice exam aiming to reinforce knowledge about genetic causes and management of specific metabolic disorders typically encountered in infancy. The provision of commentary and references seems intended to aid in understanding the rationale behind each question's correct answer.

Keywords

Biochemical Genetics

Claudia Barnett

Leigh Syndrome

mtDNA mutation

MT-ATP6

biallelic mutations

Maple Syrup Urine Disease

metabolic decompensation

newborn screening

practice exam