Blip In Genetic Code, ‘The Intellience Gene,’ for IQ And Brain Size

Is Intelligence Genetic?

An international team of scientists claims that it has found “an intelligence gene,” the wire service Agence France-Presse (AFP) reported Sunday.

http://www.google.com/hostednews/afp/article/ALeqM5h7gYRMF5mYp-vUbSUIwAjx03IOdw?docId=CNG.2fd49f1d35b6ebb0abee3c649c6274c0.261

Researchers made their finding during a study of brain scans and DNA samples from more than 20,000 people of European ancestry from North America, Europe and Australia, according to the wire service.

While trying to find genetic links to brain disease, researchers came upon a tiny variant in a gene called HMGA2. People who had larger brains and posted high scores on IQ tests tended to have this gene variant, according to AFP.

Researchers stressed that merely having this gene “blip” was just one of many factors in terms of  human intelligence, with education and environment also playing a role.

In its story, AFP offered a detailed explanation of the gene permutation.

DNA is comprised of four chemicals “called A (for adenine), C (cytosine), T (thymine) and G (guanine), strung together in different combinations along a double helix,” the wire service reported.

“‘In this case, the researchers found that people with a double ‘C’ and no ‘T’ in a specific section of the HMGA2 gene had bigger brains on average,” according to AFP.

“People who received two Cs from their parents, a quarter of the population, scored on average 1.3 points higher than the next group — half of the population with only one C in this section of the gene,” AFP reported. “The last quarter of people, with no Cs, scored another 1.3 points lower.”

Researchers conceded that the change in scores is low, but that it would be “noticeable” in a test, according to AFP. Scientists also pointed out that this gene blimp may make a person less vulnerable to cognitive decline as they age.

The genetic change impacted not only intelligence but brain size, according to the study.

“The team found that every ‘T’ in place of a ‘C’ represented a 0.6 percent smaller brain — equal to more than a year’s worth of brain loss through the normal aging process,” AFP wrote.

The wire service quoted a researcher as saying that prior studies had liked some genes to IQ, but none before had ever tied genes to brain size.

The study, from a project called Enigma, was published in Nature Genetics and involved more than 200 scientists from 100 places around the world.