The new study is actually based on previous work by Yale researchers, who discovered a different group of variants associated with an increased risk of opioid addiction in African Americans.
A genome-wide analysis of more than 5,000 opioid users has revealed a gene variant associated with opioid dependence in European Americans.
An increased risk of addiction in European Americans was associated with a variant of the Repulsive Guidance Molecule Family Member A (RGMA) gene, which is involved in cell death and nerve damage.
Senior author Dr Joel Gelernter said, “We hope that a better understanding of the biological influences on opioid use will lead to novel treatments — biological knowledge can lead to treatments, and these are needed rather desperately for opioid dependence.”
The variant RGMA allele was found more frequently in subjects of European ancestry who were opioid-dependent. The researchers reported Feb. 22 in the journal Biological Psychiatry.
RGMA has likewise been associated with damage caused by stroke, Alzheimer’s Disease, and Parkinson’s Disease.
In 2014, Gelernter and his team recognized diverse variants in African Americans involved in potassium and calcium signaling in nerve cells that were linked to increased risk of opioid addiction. That genome-wide association study failed to turn up gene variants linked to dependency in European Americans. When the study population was expanded, the link to RGMA was found.
Gelernter said the study likewise gave more limited evidence that an RGMA variant increases the risk for opioid dependence in African Americans, but the association was much stronger among people of European ancestry.
Dr John Krystal, chair of Yale’s Department of Psychiatry and editor of Biological Psychiatry, stated, “Genes responsible for opioid dependence have been difficult to identify, as the disorder stems from a complex combination of genetic alterations and environmental influences, such as drug availability.”