Genetic testing clarifies diagnosis and treatment in a family with both HNF1A and type 1 diabetes

Abstract

Confirming a diagnosis of diabetes may often be straightforward but identifying the actual type of diabetes may not always be obvious, particularly in those with a family history of diabetes. Use of non-genetic tests, such as pancreatic antibodies, may assist in the classification of diabetes but is not routine practice. The introduction of molecular genetic testing may confirm a diagnosis of monogenic diabetes but may be considered by some health care professionals to be expensive and unnecessary, particularly if treatment change is unlikely. However, a positive genetic result may lead to successful transfer from insulin to sulphonylurea treatment in many cases with improvements in glycaemic control and quality of life. This paper describes a family with diabetes diagnosed below the age of 22 years in three individuals, and the confirmation of both HNF1A and type 1 diabetes within the family. This case highlights the importance of both genetic and non-genetic tests in confirming a diagnosis. Copyright © 2009 John Wiley & Sons.