Professional and Linguistic Assessments Board (PLAB) Practice Exam

What is the genetic mutation associated with MODY?

1. GLUT2

2. HNF-1A

3. INS

4. GCK

The correct answer is: HNF-1A

Maturity Onset Diabetes of the Young (MODY) is primarily associated with specific genetic mutations that affect insulin secretion and glucose metabolism. The most common genetic mutation linked to MODY is in the HNF-1A gene, which is a transcription factor involved in the regulation of insulin gene expression and pancreatic development. Mutations in this gene lead to a form of diabetes characterized by an autosomal dominant inheritance pattern, typically presenting in adolescents or young adults. HNF-1A mutations result in impaired insulin secretion, particularly in response to glucose, leading to hyperglycemia. The identification of HNF-1A mutations is crucial for both the diagnosis of MODY and the management of affected individuals, as they may respond well to certain oral antihyperglycemic medications such as sulfonylureas. The other genetic mutations mentioned, while also implicated in different forms of MODY or other types of diabetes, do not have the same prevalence or significance as HNF-1A in the context of MODY diagnosis. For example, mutations associated with GCK (Glucokinase) lead to a different form of diabetes known as MODY2, which typically results in milder hyperglycemia and a lower risk of complications, often requiring minimal