First "molecular clock" for kids could reveal early signs of autism
There can be quite a difference between the number of candles on your birthday cake and the physical age of your body. This discrepancy, known as a biological age as opposed to a typical chronological age, can reveal health problems associated with premature aging in adults, and now scientists have devised a tool to study it in children for the first time.
This newly published research centers on the science of epigenetics, which refers to alterations in gene expression that can come about by environmental factors, changing how our cells and tissues behave without changing the underlying DNA sequence. This field of study has shown promise as a way of identifying health concerns, such as breast and cervical cancers in adults, and now scientists at Canada’s University of British of Columbia want to explore its potential with regard to young children.
“We have a good idea how these DNA changes occur in adults, but until now we didn’t have a tool that was specific for children,” says Dr. Michael Kobor, senior study author. “These DNA changes occur at very different rates in kids and so we adapted this technique for younger ages.”
The new tool is described as a “molecular clock” or, in even more scientific terms, the Pediatric-Buccal-Epigenetic (PedBE) clock. It works by detecting chemical units that attach themselves to DNA and influence which genes are switched on and off, a process known as DNA methylation. All kinds of environmental factors may drive DNA methylation across a person’s life, ranging from diet to stress to trauma.
The team started by building DNA methylation profiles of 1,032 healthy children of ages ranging from a few weeks old to 20 years old. From there, the team was able to identify 94 sites around the genome that together could reveal a child’s age, with a margin for error of around four months. On the more "biological clock" side of things, this technique could also indicate how long children spent in the womb, with those remaining there for longer periods exhibiting accelerated DNA changes.
“This powerful and easy-to-use tool could be used by clinicians to identify why some children aren’t meeting early milestones and potentially diagnose children with developmental disorders earlier in life,” says Dr. Lisa McEwen, lead study author. “This would enable doctors and pediatricians to intervene sooner in a child’s life leading to better outcomes for kids.”
Exploring these possibilities a little further, the team conducted a small pilot study concerning children with autism spectrum disorder. Those with the condition exhibited a higher age according to the molecular clock than those without it, raising the prospect of this technology finding use as a diagnostic tool for autism spectrum disorder.
“The fact that our pediatric clock was able to distinguish between typically developing children and those with autism in this small experiment demonstrates the powerful potential of this tool,” says Dr. Kobor. “Although more research is needed to confirm this, these results show that the PedBE clock could be an important factor in evaluating how children develop.”
The research was published in the journal Proceedings of the National Academy of Sciences.