Kids grow and change so fast. One day, they’re learning to walk. The next day, they’re Twittering and texting while driving your car. In the first study to analyze age-related DNA methylation (DNAm) changes in pediatric blood samples, an all-star cast of researchers out of Emory University now report that DNAm changes more rapidly during childhood than during adulthood—something to keep in mind when performing pediatric epigenetic studies.
Researchers from Emory University examined the methylation of 27,578 CpGs in blood samples from a group of boys and found age-related changes at 2078 loci. They got similar results when they studied samples from an independent group of boys. Here are a few more things they learned:
- Many of the DNAm changes in adult populations also were in the pediatric populations, suggesting that age-related DNAm changes continue throughout life.
- The X chromosome had few age-methylated loci. The researchers say this might be because the subjects were male, and their single X chromosome may be less tolerant of DNAm variations.
- They also found evidence that demethylation events depend on the surrounding nucleotides, but they couldn’t find a similar pattern for methylation events.
- Most of the changes were on loci associated with developmental and immune systems.
- The pediatric data didn’t fit a linear trend, like data from adult DNAm studies did. Instead, a logarithmic model was better.
“These results offer evidence that age-associated DNAm changes occur more rapidly in children than adults,” say the researchers. Their advice? Make sure the subjects in your next epigenetic study are matched by age.
Read all the details at Genome Research, February 2012.