Marks on a baby’s DNA might be able to predict whether he or she may develop conduct problems later in life, suggests new research published in Development and Psychopathology. Conduct problems — such as lying, stealing, and fighting — fit into a spectrum of behavioral and emotional issues found in youngsters in which basic social rules or the rights of others are violated. These behaviors are known to have a link to genetic factors and environmental influences. Now, there may also be an underlying epigenetic connection.
Kids who demonstrate conduct problems (CP) prior to the age of 10, or early-onset CP, are at a greater risk for long-term and severe antisocial behaviors for the duration of their lives. This could potentially increase social costs connected to crime, healthcare needs, and welfare dependence.
Genetic factors typically explain between 50 and 80 percent of the differences among children who develop CP versus those who do not. The ways in which the environment influences genetics, however, is much less understood and requires further investigation.
Senior author of the study from King’s College London, Dr. Edward Barker, said, “We know that children with early-onset conduct problems are much more likely to engage in antisocial behavior as adults, so this is clearly a very important group to look at from a societal point of view.”
By studying changes in DNA methylation, a well-known epigenetic mechanism that controls whether genes are switched “on” or “off”, scientists can uncover new ways in which we may be able to prevent conduct problems from arising in children.
Researchers from the King’s College London utilized data from Bristol’s Avon Longitudinal Study of Parents and Children (ALSPAC) and uncovered a relationship between this epigenetic mark found at particular locations on the genome and CP in children between the ages of 4 and 13. DNA methylation was significantly different across numerous sites on the DNA of a child who later went on to develop early-onset CP compared to those who did not.
One gene they assessed, known as MGLL, had the most significant epigenetic alterations. This gene has been shown to be involved in addiction, pain perception, and reward. Interestingly, previous research indicates that CP is usually accompanied by substance abuse and some individuals who are antisocial can tolerate higher levels of pain. Other genes, including MAOA, had smaller differences in methylation and have links to antisocial behavior and aggression.
Environmental exposures were also assessed in the study. Prenatal exposures, like alcohol use and smoking during pregnancy, were connected to CP. Similarly, a genome-wide consortium meta-analysis showed that maternal smoking epigenetically harms child development with a distinct epigenetic signature.
“There is good evidence that exposure to maternal smoking and alcohol is associated with developmental problems in children, yet we don’t know how increased risk for conduct problems occurs,” noted Dr. Barker. “These results suggest that epigenetic changes taking place in the womb are a good place to start.”
The study’s first author, Dr. Charlotte Cecil from King’s College London, added, “Our study reveals significant epigenetic changes which differentiate children who go on to develop conduct problems and those who don’t. Although these findings do not prove causation, they do highlight the neonatal period as a potentially important window of biological vulnerability, as well as pinpointing novel genes for future investigation.”
The results indicate a possible link between epigenetic tags and conduct problems, but the researchers cannot definitively say that one causes the other. However, additional research will help elucidate this connection and further supports the influence of the postnatal environment on a child’s development. It will be interesting for future studies to assess whether positive environmental cues could modify these potentially detrimental epigenetic changes and improve a child’s risk for developing behavioral problems as they get older.
Source: Cecil, C. et al. (2017). Neonatal DNA methylation and early-onset conduct problems: A genome-wide, prospective study. Development & Psychopathology, doi: 10.1017/S095457941700092X.
Reference: King’s College London. Epigenetic changes at birth could explain later behaviour problems. News, 12 June 2017. Web.
