Consumption of even moderate amounts of alcohol during pregnancy affects the activity of genes in the developing fetus and that these changes last into adulthood, Australian researchers have shown.
"We have long known that alcohol consumption during pregnancy can harm the developing fetus and have life-long effects on the individual's health and well being. What our current research helps to explain is the underlying mechanism," said researcher Dr Suyinn Chong from the Epigenetics Laboratory at Queensland Institute of Medical Research (QIMR).
The research was carried out in in collaboration with the Sigrid Juselius Foundation, Finland, and the University of Washington, Seattle.
"This is a new and exciting area where instead of studying the sequence of the genes, we are looking at the mechanisms that control our genes - known as epigenetics. This is an extra layer of information attached to your DNA which helps regulate the expression of genes - in other words whether they are switched on or off. These epigenetic changes determine whether a gene is converted into protein, which ultimately controls physical traits."
"Using mice as a model, we have shown for the first time that alcohol consumed during the first trimester affects the developing fetus by altering the epigenetic information."
The researchers used specific mice, whose fur colour reflected these epigenetic changes. Half the mothers drank relatively moderate amounts of alcohol (equivalent to a peak blood alcohol reading of 0.12 in humans) during pregnancy, while the other half consumed water.
The mice that drank alcohol had twice as many dark-furred offspring compared to mothers who were not exposed to alcohol. The resulting change in coat colour is an indication of the changed epigenetic state of the coat colour gene.
Some alcohol-exposed offspring exhibited subtle skull malformations, similar to features seen in human fetal alcohol syndrome (FAS) - a condition that causes growth restriction, intellectual disabilities and changes to the shape and size of the skull as a result of high levels of alcohol consumption during pregnancy.
FAS has devastating long-term consequences for the individuals themselves and their families and the number of reported cases in Australia is increasing.
Dr Chong is hopeful her team's research will further our understanding of fetal alcohol spectrum disorders and in the future these epigenetic changes may be used to aid diagnosis of this condition, allowing for early intervention.
The paper was published in PLoS Genetics
on 15 January.