New York, Jan 7 (IANS): Researchers from North Carolina-based Duke University have identified a gene variant that may serve as a marker for children who are among society's most vulnerable.

The findings are a step toward understanding the biology of what makes a child particularly sensitive to positive and negative environments.

"This gives us an important clue about some of the children who need help the most," said Dustin Albert, research scientist at the Duke University's Centre for Child and Family Policy.

The study found that children from high-risk backgrounds who also carried a certain common gene variant were extremely likely to develop serious problems as adults.

Left untreated, 75 percent with the gene variant developed psychological problems by age 25, including alcohol abuse, substance abuse and antisocial personality disorder.

The picture changed dramatically, though, when children with the gene variant participated in an intensive program called the Fast Track Project.

During the project, researchers screened nearly 10,000 kindergartners for aggressive behaviour problems, identifying nearly 900 who were at high risk, and assigning half of that group to receive intensive help.

After receiving support services in childhood, just 18 percent developed psychopathology as adults.

"It is a hopeful finding. The children we studied were very susceptible to stress. But far from being doomed, they were instead particularly responsive to help," Albert noted.

The findings could be a first step toward potential personalised treatments for some of society's most troubled children.

The study appeared in the Journal of Policy Analysis and Management.