Are genes responsible for your educational level?Los Angeles, May 16(AZINS) The educational level a person obtains could be due, in part, to the genes carried by them, according to a new study.

Genes that are correlated with educational attainment are expressed in the brain during prenatal development. Some of the genes also predict risk for Alzheimer's disease, bipolar disorder, and schizophrenia, researchers said.

An international group of scientists conducted one of the largest genetic studies to date and identified 74 genetic variants that are associated with the years of formal education that an individual completes.

"This study builds on our earlier work in which we had studied 100,000 individuals and found three genetic variants linked to educational attainment," said Daniel Benjamin from the University of Southern California in the US.

This time, because of our much larger sample -- almost 300,000 individuals -- we were able to identify far more genetic variants that are associated with educational attainment," said Benjamin.

He said that genetic and environmental factors both account for variation in how much schooling a person receives.

Genes only partially influence cognitive abilities and personality traits, such as persistence, that in turn affect the number of years one spends in school, researchers said.

"Educational attainment is jointly influenced by genes and environment. The genetic variants that we found, account for a small fraction of the differences across individuals in education," he said.

Scientists combined results from 64 datasets comprising subjects in 15 different countries. They identified the genetic variants associated with an individual's total years of education. The analysis was restricted to people of European descent.

The total influence of the 74 identified genetic variants is small, explaining about 0.43 of 1 percent of the variation in educational attainment across individuals, researchers said.

"For the variant with the largest effect, the difference between people with zero copies and those who have two copies of the variant predicts, on average, about nine more weeks of schooling," said Benjamin.

"The results suggest that the genetic influences on educational attainment are spread across thousands, if not millions, of genetic variants, most of which have not yet been identified," he added.

By combining their own results with data from previous studies, researchers found that many of the genes associated with educational attainment are influential in brain development, even before birth.

Scientists said these genes likely play a role in cognitive function and personality traits, such as grit, that matter for school performance.

"The tiny genetic differences we found may ultimately help to understand why some people are more susceptible to early cognitive decline than others," said Peter Visscher from Queensland Brain Institute in Australia.

The findings were published in the journal Nature.