Epigenetics of bullies

DNA methylation predicted child crime

Experts from the UK, USA and Canada have found seven loci whose methylation is associated with the risk of delinquent behavior.

Denis Strigun, Naked Science

Antisocial (delinquent) behavior is the main reason for prescribing psychotherapy to young people. In addition to direct damage to health and property, such patients impose an additional burden on the economy, medicine and social services. The development of such deviations is associated with early childhood. It is assumed that their manifestation is determined by a combination of burdened heredity (explanatory ability – 50-80 percent), environmental factors, in particular smoking of the mother during pregnancy, and unfavorable environmental conditions (poverty, abuse). However, the exact biological mechanisms of antisociality are unclear.

In recent years, the etiology of various diseases is often considered in terms of epigenetic changes, in particular DNA methylation. This modification consists in attaching a methyl group to the cytosine without changing the nucleotide sequence. According to one hypothesis, the accumulation of methylated cytosine occurs under the influence of stressors and through genes mediating the work of the hypothalamic-pituitary-adrenal system, affects the psyche and behavior. However, due to methodological limitations, past work on the relationship between DNA methylation and delinquency did not allow the epigenome to be attributed to risk factors or correlates of psychopathologies.

To fill in the gap, the staff of King's College London and other institutions conducted a prospective study – unlike retrospective and cross-sectional, it involves assessing the dynamics of the same respondents. Details of the study are presented in the journal Development and Psychopathology (Cecil et al., Neonatal DNA methylation and early-onset conduct problems: A genome-wide, prospective study).

The authors examined the cases of 321 children, data on which were collected in the period from four to 13 years as part of a longitudinal survey of 14541 pregnant women from the UK by ALSPAC. Based on a survey of successes and difficulties, scientists divided children into three categories: early manifestations and a consistently high level of antisocial behavior (EOP); early manifestations and improvement of symptoms as they grow older (CL); and low level of symptoms (low CP).

Differential methylation loci in children
with early delinquent symptoms (dark gray)
and healthy children (light gray).

The mental status of children was compared with sociodemographic parameters, prenatal risks and DNA methylation. The analysis showed that the genome of children with early manifestation of antisocial behavior contains seven loci with a specifically high level of methylation. For example, modifications were observed in the region of the regulated MGLL promoter – this gene is involved in nociperception (pain perception) and endocannabinoid signaling; TTBK2, whose mutations are associated with neurodegenerative diseases; and GCET2, which provides an immune response. A number of loci correlated with prenatal risks: smoking and alcohol consumption in the first trimester.

Portal "Eternal youth" http://vechnayamolodost.ru  15.06.2017