Type 2 diabetes and genetics: What is the link?

  • A recent type 2 diabetes study looked at the genetic profiles of more than 180,000 people.
  • Unlike previous studies that focused primarily on people with European ancestry, nearly half of the people in this study had non-European ancestries.
  • By the end of the study, the scientists discovered 40 previously unreported genes that contribute to developing type 2 diabetes.

Recently published research in Nature Genetics featured the most diverse genetic study on type 2 diabetes.

While scientists are aware of certain factors that may increase a person’s risk of developing type 2 diabetes, one major question is what role genetics plays.

Researchers from the US and England collaborated to analyze the DNA profiles of thousands of people of varying ancestries. In doing so, they not only identified new genes that contribute to type 2 diabetes, but they also became a step closer to developing a genetic risk score for the disease.

Type 2 diabetes occurs when a person’s body does not make enough or use insulin effectively, making it difficult for the body to regulate blood sugar levels. It can be life threatening if someone’s blood sugar levels get too high or low.

The Centers for Disease Control and Prevention reports that around 37 million Americans have diabetes, and around 90-95% of these people have type 2 diabetes.

According to the American Diabetes Association, a person with type 2 diabetes may experience some of the following symptoms:

  • Blurry vision
  • Increase in thirst and hunger
  • Wounds that heal slowly
  • Fatigue
  • Frequent urination

If a person suspects they have type 2 diabetes, they can consult with their physician, who can order a blood test to check for the disease.

There is not a cure for type 2 diabetes, but people with the disease can manage their blood sugar levels by taking medications and avoiding foods that spike blood sugar levels.

While there is a lot of research on type 2 diabetes, much of it has primarily targeted people of European ancestry.

“Risk scores derived from one ancestry often do not transfer well to others,” explained Professor Nathan Tucker in an interview with Medical News Today. “Inclusion of diverse ancestries helps us understand the mechanisms of the risk, improving the probability of successful therapeutic development.”

Prof. Tucker is an assistant professor and genetics core manager at Masonic Medical Research Institute in Utica, NY.

The authors also noted that genetic risk scores “provide unreliable prediction when deployed in other population groups.”

The researchers accessed data from other studies to create the Diabetes Meta-Analysis of Trans-Ethnic association studies (DIAMANTE) Consortium. They analyzed the genetic makeup of 180,834 individuals with type 2 diabetes and compared it to 1,159,055 people without diabetes.

The scientists placed people in 1 of 5 groups: European ancestry (51.1%); East Asian ancestry (28.4%); South Asian ancestry (8.3%); African ancestry (6.6%); and Hispanic ancestry (5.6%).

By comparing the DNA of the people with type 2 diabetes to those without, the researchers were able to identify more than 200 loci that were genetically significant in terms of developing the disease.

According to the National Human Genome Research Institute, a locus (or loci in the plural form) “is a physical site or location within a genome (such as a gene or another DNA segment of interest.).”

“This study identifies 237 genomic regions that are associated with altered risk of type 2 diabetes, with nearly 100 evidence-based targets that are prioritized for the next stages of therapeutic development,” Prof. Tucker explained.

The researchers also identified genes that may contribute to developing type 2 diabetes.

“We have now identified 117 genes that are likely to cause type 2 diabetes, 40 of which have not been reported before. That is why we feel this constitutes a major step forward in understanding the biology of this disease,” says Professor Anubha Mahajan.

Dr. Mahajan is a human genetics researcher and professor at the University of Oxford in England.

The sheer magnitude and diversity of this study create enormous potential for being able to one day identify a person’s genetic risk for type 2 diabetes.

“Inclusion of diverse ancestries helps us understand the mechanisms of the risk, improving the probability of successful therapeutic development,” Prof. Tucker commented.

Dr. Brian Fertig, the Founder and President of the Diabetes and Osteoporosis Center in Piscataway, NJ, also spoke with MNT regarding the study.

“The findings of this study are not surprising because diagnostic and therapeutic stratifications are too often overly simplified as ‘one size fits all,” Dr. Fertig said.

Dr. Fertig also thought the study emphasized the importance of diversity and inclusion in research.

“This data underscores the need for a precision, personalized and dynamic scale of medicine, as it’s rare to see two diabetics with the same clinical and biochemical profile,” Dr. Fertig commented. “Every individual is unique and as such should have individualized treatment plans.”

https://www.medicalnewstoday.com/articles/type-2-diabetes-new-study-identifies-40-more-genes-linked-to-the-disease