rs10732516 polymorphism at the

study questionDoes prenatal alcohol exposure (PAE) affect regulation of the SUMMARY ANSWER: PAE results in genotype-specific trends in both placental DNA methylation at the WHAT IS KNOWN ALREADY: PAE can disturb development of the nervous system and lead to restricted growth of the head, even microcephaly. To clarify the etiology of alcohol-induced growth restriction, we focused on the imprinted STUDY DESIGN SIZE DURATION: By grouping 39 alcohol-exposed and 100 control samples according to rs10732516 polymorphism we explored alcohol-induced, genotype-specific changes in DNA methylation at the PARTICIPANTS/MATERIALS SETTING

methodsWe explored alcohol-induced, genotype-specific changes in placental DNA methylation by MassARRAY EpiTYPER and allele-specific changes by bisulphite sequencing. MAIN RESULTS AND THE ROLE OF CHANCE: We observed a consistent trend in genotype-specific changes in DNA methylation at LIMITATIONS REASONS FOR CAUTION: Owing to the exceptional character of the alcohol-exposed human samples collected in this study, the sample size is restricted. An increased sample size and functional studies are needed to confirm these data and clarify the biological significance or causality of the observed associations. WIDER IMPLICATIONS OF THE

findingsOur results suggest that the rs10732516 polymorphism associates with the alcohol-induced alterations in DNA methylation profiles and head growth in a parent-of-origin manner. We also introduce a novel genotype-specific approach for exploring environmental effects on the STUDY FUNDING/COMPETING INTERESTS: This work was supported by the Academy of Finland (258304), The Finnish Foundation for Alcohol Studies, Finnish Cultural Foundation, Juho Vainio Foundation, Yrjö Jahnsson Foundation and Arvo and Lea Ylppö Foundation. No competing interests are declared.