Scientists have uncovered a genetic variation linked to opioid addiction, according to newly-published research.
Yale University researchers analyzed the DNA of nearly 5,000 opioid drug-users and identified genetic makers shared by European Americans suffering from addiction to opioids.
Their new study comes after the same team identified a similar variation in African American populations predisposed to addiction.
The scientists recognize that opioid addiction – which affects an estimated 2.1 million Americans – is the result of many environmental and inborn factors, but their pair of studies may offer a gateway to the development of new treatments, they claim.
Americans who try and become dependent on opioids share common DNA, Yale University researchers discovered
Unraveling how the opioid epidemic got so bad in the US has preoccupied countless researchers in nearly as many fields: from public health experts and epidemiologists to addiction specialists and geneticists, like Dr Joel Gelernter.
Gelernter and his team at Yale University have been searching for a genetic key to opioid addiction for years.
In 2014, they discovered a gene shared among African Americans at an elevated risk of addiction to powerful drugs like OxyContin, heroine and fentanyl.
Now the researchers have found that the same composite of genetic factors is shared by many Americans – both black and white – who become addicted to opioids.
While some experts have predicted that, epidemiologically speaking, we may be past the peak of the epidemic, the crisis rages on, and the federal government’s efforts to stop it through educational campaigns seem to have had little effect.
The opioid epidemic has been driven by prescription drugs and fentanyl, much research suggests, and many states have implemented drug monitoring and expanded treatment programs, but most of those use opioid substitutes, and then ‘we are replacing heroine [or other opioid addiction] with methadone addiction, that’s essentially what it is,’ says Dr Gelernter.
Many addiction specialists would disagree, and Dr Gelernter says that, for now, methadone is a good treatment, but that ‘in terms of pharmaceutical treatments, we have very little.’
‘we need new treatments for opioid dependence because it is an enormous problem not just in the US, but worldwide,’ he adds.
The genetic discoveries he and his have made might just be the key entirely new approaches to treating opioid addiction.
We have long known that genetics play role in addiction in general, whether it be to alcohol, drugs or nicotine.
But genetics is not a one-to-one science: For nearly any given trait – whether physical or behavioral – there is very rarely a single gene responsible for the phenotype, or expression.
The same is true for the genetics of addiction, Dr Gelernter explains.
‘General epidemiological studies predict that we should find genetic factors specific to different substances and that are common between substances, and we’re beginning to see that,’ he says.
Dr Gelernter and his fellow researchers found a ‘risk allele,’ called RGMA, that occurred more frequently in both European and African Americans who used and became addicted to opioids than those that had used the drugs but reported that they were not dependent on them.
The risk allele is ‘composed of many small contributions from numerous genetic variants,’ Dr Gelernter says.
This is not the first gene to be linked to opioid addiction.
In 2016, researchers discovered another risk allele, a variant of CNIH3, that was linked to opioid addiction.
The two factors are part of a potentially much larger network of genetic risk factors for addiction disorders related to the category of drugs.
But the Yale discovery gives scientists reason for hope: RGMA codes for a certain kind of protein that can serve as a ‘target’ for addiction treatments, Dr Gelernter says.
‘Ideally, people who work for drug companies that have been working on opioid dependence treatments might think that here is another window into the brain mechanisms of addiction.
‘Maybe if we have a compound that affects that expression, it could be a compound for opioid dependence,’ he says.