Gene variant may foretell success in program for at-risk kids

A particular genetic variant can indicate whether children at risk for developing serious behavior problems are more likely to benefit from an early intervention program, a new study shows.

Researchers are a long way, though, from being able to conduct genetic tests to identify grade-schoolers most likely to respond to such programs, cautions psychologist Dustin Albert of Duke University in Durham, N.C. When that day comes, society will have to grapple with the ethics of genetically screening at-risk kids, he predicts.

Albert and his colleagues followed white youngsters who were highly disruptive and aggressive as kindergartners, and who inherited one or two copies of a gene variant involved in regulating the body’s stress responses. Most of those who received an intensive intervention from grades one through 10 displayed dramatic behavior changes for the better as young adults, the scientists say. Only 21 of 114 kids in this group, or 18 percent, had abused alcohol and drugs and committed delinquent or criminal acts by age 25, Albert’s team reported online January 5 in the Journal of Policy Analysis and Management.

A second group of kids with just as severe behavior problems and who inherited the same version of the stress gene received no intervention – and did especially poorly. As young adults, 96 of 128 of them, or 75 percent, displayed drug and delinquency problems.

Researchers also looked at at-risk children carrying other versions of the stress gene. Slightly more than half reported drug and behavior problems by age 25, whether or not they had received the 10-year intervention while in school.

Further analyses, reported by Albert’s group in the February issue of Development and Psychopathology, indicate that, among kids with the key gene variant, the intervention led to grade-school behavior improvements. Even greater improvements occurred from adolescence to young adulthood. And participants with two copies of the modified gene benefited more from the intervention than those with one copy. “Biological sensitivity to one’s environment may be related to the stress response system,” Albert says.

Children with the crucial gene variant clearly got the biggest boost by age 25 from the intervention, says psychologist Michael Pluess of Queen Mary University of London in England. However, a fairly big range of variation in age-25 outcomes for nonintervention kids suggests that those with and without the key gene variant ended up with comparable rates of behavior problems, Pluess holds. Albert counters that it’s likelier that participants with the crucial gene arrangement developed more behavior problems than anyone else in the study.

His team tracked 270 white children tagged by parents and teachers as being highly disruptive upon entering kindergarten. Children attended public schools in high-crime, low-income parts of Durham, N.C.; Nashville, Tenn.; rural Pennsylvania and Seattle. Kids were randomly assigned in the early 1990s to receive a long-term intervention that included regular social skills training, parent training, academic tutoring and help with individual problems at home and at school.

Once kids turned 21, researchers collected their DNA from cheek swabs. The team identified 10 versions of the glucocorticoid receptor gene in participants. This gene influences transmission of the stress hormone cortisol. Several glucocorticoid receptor gene variants have been tied to alcohol abuse and mood disorders.

Only one gene variant showed a link to favorable intervention effects, at least for white youngsters, Albert says. For unclear reasons, none of these gene variants signaled responsiveness to the behavioral program among 127 high-risk black youngsters tracked to age 25. Hundreds of genes influence responses to behavior programs such as the one in the new studies, Albert suspects.