Placental miRNAs Predict Infant Behavior

Many parents consider their children’s behavior to be a bit of a mystery, (just ask anyone who has shared a plane ride with an unruly toddler) but new miRNA research hints that it may soon be possible to predict your child’s behavioral traits by a simple non-invasive test right after birth. A fortune telling team from Brown University has laid some of the groundwork for just such a ‘magical’ future application of clinical epigenetics.

Building on the knowledge that a number of environmental factors can affect the outcome of a pregnancy, including neurodevelopment, Dr. Marsit and team set out to translate current research to the next level. The Brown scientists wanted to see whether environmentally altered expression levels of miRNAs in the placenta were associated with altered neurobehavioral outcomes. While controlling for potential confounding variables their crystal ball revealed that:

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  • High miR-16 expression is significantly associated with decreased infant attention score, which is “reflective of an overall poor quality of response and reduced infant alertness.”
  • High miR-146a and miR-182 expression are significantly linked with higher infant quality of movement scores, defined as “…infants who exhibit smooth movement with a low degree of jitteriness, tremors and startles and relatively average amounts of spontaneous and elicited motor activity”
  • Interestingly, the authors have previously found that in utero exposure to cigarette smoke leads to a down-regulation of miR-146a, suggesting that tobacco smoke exposure may elicit some of its negative effects on a child’s behavior through alteration of miRNA expression.

Ultimately, this work suggests “miRNA may be affecting key neuro-active peptide and hormone production by the placenta. These alterations may be additional mode(s) through which the environment can impact infant neurobehavioral development.” However, the authors also acknowledge that their “work is limited by an inability to definitively test causality”. These associations observed have to be further tested using model systems, but pave the way for discovering more complex associations between the epigenome and environment.

Gaze into the miRNA Crystal Ball in Pediatric Research, June 2013