genetic testing

New Research Sheds Light on Benefits of Genetic Testing for Diabetes

According to researchers at the University of Maryland School of Medicine, approximately 1% of patients with diabetes, or over 300,000 individuals in the United States and several million worldwide, have a monogenic form that is often misdiagnosed. The Monogenic Diabetes Research and Advocacy Consortium (MDRAC) is a group of patients, providers, and researchers dedicated to recognizing, diagnosing, and promoting individualized therapy for people with all types of diabetes, particularly monogenic diabetes. Toni Pollin, PhD, Associate Professor of Medicine and Epidemiology & Public Health at the University of Maryland School of Medicine, is one of the founders the Monogenic Diabetes Research and Advocacy Project and Monogenic Diabetes Research and Advocacy Consortium. Her research focuses on identifying genes that influence risk of type 2 diabetes, related diseases, and responses to treatment and on identifying strategies to integrate genomic knowledge into medicine, particularly in monogenic diabetes.

Benefits of Genetic Testing for Diabetes

"Approximately 1% of cases of diabetes are Mendelian (monogenic), where a mutation in a single gene is sufficient to cause disease." says Pollin. "These Mendelian subtypes include neonatal diabetes, maturity-onset diabetes of the young (MODY), and syndromic forms. Genetic testing in diabetes is important because it's estimated that over 80% of patients with MODY are misdiagnosed as having Type 1 or 2 diabetes and would benefit from alternative treatments. The focus right now is to identify the individuals who have monogenic diabetes and could benefit from known customizations of treatments," Pollin explains.

A diagnosis of HNF4A- or HNF1A-diabetes (also called MODY1 and MODY3) indicates that the most effective treatment, especially early in the disease course, is likely to be low dose sulfonylurea pills. This treatment promotes insulin secretion rather than the insulin injections used to treat type 1, or the metformin (which promotes insulin sensitivity) usually tried first for type 2 diabetes.

A diagnosis of GCK-diabetes (also called MODY2), which causes stable mild hyperglycemia, usually indicates that no treatment is needed because this mild hyperglycemia is generally not associated with the complications seen in other types of diabetes.

A diagnosis of ATP-sensitive potassium (KATP) channel diabetes, caused by mutations in KCNJ11 or ABCC8 and typically occurring in infancy, usually allows patients to transition from insulin injections to high dose sulfonylurea pills, often with improvements in glucose control.

Incorporating Genetic Testing into Diabetes Care

Recent studies suggest that monogenic diabetes is only correctly diagnosed about 5% of the time. The Center for Diabetes and Endocrinology located on the University of Maryland Medical Center's Midtown Campus is one of only a handful of Centers that offer genetic counseling for patients with diabetes based on a variety of indications and guidelines. Genetic counselors are health professionals who work with patients, families their physicians and other healthcare providers to identify and communicate about genetic risks and testing options and results and provide related psychosocial support. Results of genetic testing are quickly translated into improved treatment and services for patients. "Once we do a better job identifying these individuals, it will likely be possible to conduct clinical trials for approaches to improving the health and quality of life of these individuals even more," says Pollin.

For more information about the Monogenic Diabetes Research and Advocacy Project, call 410-706-1630.

To refer a patient for genetic counseling at the University of Maryland Center for Diabetes and Endocrinology, please call 443-682-6800 and ask for a diabetes genetic counseling appointment.