Extensive study identifies genes linked to heavy drinking and alcoholism

3 Apr 2019

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A genomics study of nearly 275,000 people has found unique genetic variants that could help develop treatments for alcoholism.

Researchers have spent years trying to tap into our genetic data to find links with a whole range of different disorders, and among the most destructive are ‘heavy drinking’ and alcohol use disorder (AUD), otherwise known as alcoholism.

Now, a team from the University of Pennsylvania School of Medicine has published findings on the largest ever genome-wide association study of the pair, encompassing almost 275,000 people. These findings showed 18 genetic variants of significance associated with either heavy drinking, AUD or both.

Future Human

Published to Nature Communications, the study was able to identify that, interestingly, while five of the variants overlapped, eight were only associated with heavy drinking and five with AUD only. Also, while heavy drinking is typically a prerequisite for AUD, variants in several genes – such as DRD2 and SIX3 – may be necessary for people to develop AUD.

“This study has revealed an important genetic independence of these two traits that we haven’t seen as clearly before,” said Dr Henry R Kranzler, first author of the study.

“Focusing on variants only linked to AUD may help identify people at risk and find targets for the development of medications to treat it. The same applies to alcohol consumption, as those variants could inform interventions to help reduce consumption in heavy drinkers, who face their own set of adverse effects.”

Important discoveries

The study by the research team used data from the multi-ethnic Million Veteran Program (MVP), a US voluntary research programme that includes white, African-American, Latino and Asian participants. Within this data were scores from their AUD screenings, AUD diagnoses and other data from health records to look for correlations between genes, diseases and other non-alcohol-related traits.

This resulted in the identification of 13 independent genetic variants associated with alcohol consumption, eight of which had not been previously reported: VRK2, DCLK2, ISL1, FTO, IGF2BP1, PPR1R3B, BRAP and RBX1. 10 variants were associated with AUD, including seven that had not been previously associated with it: GCKR, SIX3, SLC39A8, DRD2 (rs4936277 and rs61902812), chr10q25.1 and FTO. The five variants associated with both heavy drinking and AUD were: ADH1B, ADH1C, FTO, GCKR and SLC39A8.

188 different genetic correlations were also found, with AUD showing strong links with lower intelligence, greater risk of insomnia and most psychiatric disorders.

Research from the World Health Organization published last year showed that 8.5pc of Ireland’s population were categorised as having AUD, with a further 3.8pc deemed as having alcohol dependence.

Colm Gorey was a senior journalist with Silicon Republic