Genetic testing has become increasingly common, but there are still questions about how to apply it effectively in people diagnosed with diabetes. The panel discussion Diabetes Endotypes—Defined by DNA? will outline what investigators are doing to change that and highlight an initiative to improve diabetes care through precision medicine.

The session will be presented on Saturday, June 24, at 3:15 p.m. PT in Ballroom 6C-F of the San Diego Convention Center.

The American Diabetes Association® (ADA) has partnered with the European Association for the Study of Diabetes (EASD) on the Precision Medicine in Diabetes Initiative (PMDI). Objectives include:

• Improve diabetes diagnostics.
• Establish what evidence we have and what evidence is needed to develop best practice guidelines and best practice study design.
• Provide education to implement best practice guidelines and best practice research.
• Establish a research program to address open questions.
• Accelerate the process for getting access to trials and for regulatory authorization.
• Modify guidelines to incorporate new recommendations in precision medicine.

The protocol for testing for monogenic diabetes is not standardized, illustrating just one of the many needs this joint effort aims to address.  

“Correct diagnosis of monogenic diabetes improves outcomes for patients, which is a key focus of the PMDI,” said Rinki Murphy, MBChB, FRACP, PhD, an endocrinologist and Professor of Medicine at the University of Auckland, New Zealand.

People with different types of monogenic diabetes can benefit from distinct treatment pathways; however, the challenge is deciding who to test. Since monogenic forms of diabetes are relatively rare and the cost of genetic testing is still quite high, it’s not cost effective to test everyone with diabetes.

Thus far, clinical practice for detecting monogenic diabetes subtypes has been inconsistent, due to the uncertainty in determining which people to test and which genes to test for, and this inconsistency has led to gaps in testing, Dr. Murphy noted.

She called the maturity-onset diabetes of the young (MODY) terminology “obsolete” and the MODY criteria for diagnosing monogenic diabetes “inaccurate.” This is because monogenic diabetes can manifest at different ages, so it is neither a maturity onset disease nor diabetes of the young. She said newer criteria for genetic testing guidelines have recently been developed to better detect people who have different single-gene causes for diabetes or mild hyperglycemia.

“Compared to newer antibody/C-peptide biomarker informed testing, traditional MODY criteria—age of diabetes diagnosis below 25 years, non-insulin treatment and a parent affected with diabetes—has low yield and misses many subtypes of monogenic diabetes, so this is not recommended to guide testing decisions,” Dr. Murphy said.

But there are ways to perform genetic testing for monogenic diabetes more efficiently. To demonstrate this, Dr. Murphy will present various case studies that highlight clinical features to look for when considering genetic testing. She will provide insights into different ways each genetic test has improved treatment and outcomes for people living with diabetes.

As part of the panel discussion, Emma Ahlqvist, PhD, Associate Professor of Genomics, Diabetes, and Endocrinology, Lund University, Sweden, will outline endotypes of type 2 diabetes. Ashok Balasubramanyam, MD, Professor of Endocrinology, Diabetes, and Metabolism, Baylor College of Medicine, will discuss endotypes of ketosis-prone diabetes. Robert Wagner, MD, Professor, German Diabetes Center, will discuss endotypes of prediabetes.