A DNA methylation catalogue to help understand the biology of environmental exposures in children

Several studies have linked exposure to environmental factors to epigenetic alterations, such as DNA methylation. But in most cases, it has not been possible to determine whether and how these methylated sites affect the expression of neighbouring genes. This makes it difficult to understand what the effect of this methylation might be at the physiological level.

Now, a study conducted by the Barcelona Institute for Global Health (ISGlobal) has identified the association between DNA methylation patterns and the expression levels of some genes in children. These results may help to understand more precisely the relationship between environmental exposures, the resulting DNA methylation patterns, and the changes in gene expression that these patterns entail.

“Understanding these associations can help us to better interpret epigenome studies and understand the biological processes that lead to disease.”
Mariona Bustamante (ISGlobal), co-leader of the study.

In this research, blood samples from 832 children aged 6-11 years were analysed to identify associations between DNA methylation levels in certain regions and the expression of nearby genes. The results showed 40,000 significant associations. In 59% of these cases, higher levels of methylation were associated with lower gene expression.

However, only 13.8% of the associations identified were also found in adults. Carlos Ruiz-Arenas, first author and co-leader of the study, explains that “these results were expected, because DNA methylation and gene expression change with age”. He adds that “even so, the results provide a catalogue that can help to interpret association studies of the entire epigenome in the paediatric population“.