(HealthDay News) – Variants in genes involved in alcohol metabolism in children and their mothers correlate with child IQ at age 8, with the association only present for mothers who drink during pregnancy, according to a study published online Nov. 14 in PLoS One.

Sarah J. Lewis, PhD, from the University of Bristol in the United Kingdom, and colleagues used a large population-based study of women recruited during pregnancy to examine whether the association between genetic variants in alcohol metabolizing genes in women and their children correlates with the child’s cognitive score at age 8.

The researchers found that, among 4,167 children, four genetic variants in alcohol metabolizing genes correlated strongly with lower IQ. A risk allele score based on these four variants also correlated with lower IQ at age 8. This effect was not seen among children whose mothers abstained during pregnancy but was seen for offspring of mothers who were moderate drinkers (one to six units per week during pregnancy; per allele effect estimates, −1.8; P=0.00002). For mothers who drank during pregnancy, there was a further genetic variant associated with alcohol metabolism in mothers that correlated with child IQ.

“Amongst children exposed to moderate maternal alcohol consumption in utero, genetic variants in alcohol metabolizing genes are associated with childhood cognitive ability,” the authors write. “As these children’s principal alcohol exposure is likely to have been in utero, this provides evidence that moderate maternal alcohol use during pregnancy may have an adverse effect on offspring cognition.”

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