A genome-wide analysis of more than 5,000 opioid users has revealed a gene variant associated with opioid dependence in European-Americans

The new study builds upon earlier work by Yale researchers who identified a different group of variants associated with increased risk of opioid addiction in African Americans. An increased risk of addiction in European Americans was associated with a variant of the gene RGMA, which is involved in cell death and nerve damage. The variant RGMA allele was found more frequently in subjects of European ancestry who were opioid-dependent. RGMA has also been linked to damage caused by stroke, Alzheimer’s Disease, and Parkinson’s Disease. In 2014, researchers identified several 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 study population was expanded, the link to RGMA was found. The study also provided more limited evidence that an RGMA variant increases risk for opioid dependence in African Americans, but the association was much stronger among people of European ancestry.