The genetic composition that shapes the physical features that vary with sex may increase the risk of autism among children, according to a new study.
Although most of the genes that give rise to physical features such as waist-to-hip ratio are not connected with autism or even the brain, the study helps in the establishment of physical difference among the sexes, according to lead investigator Lauren Weiss. She is an associate professor of Psychiatry at the University of California, San Francisco.
In an article that appeared in the website of Scientific American, Weiss revealed the contribution of sex difference in the risk of autism. "Whatever general biological sex differences cause a [variant] to have a different effect on things like height in males and females, those same mechanisms seem to be contributing to autism risk," Weiss said.
According to the website of Spectrum where the study also appeared, this was the first research to focus on sex differences in common genetic variants called single nucleotide polymorphisms. The study concluded that autism may be linked to sexual differences but not in the total number of these features.
For the study, Weiss and her team used published genetic data from four databases as well as unpublished data from five others. The researchers reviewed information from 8,646 autistic individuals, of which 1,468 are girls and women. Data from 15,028 controls were also analyzed by the team, some of which have relations with the people in the autism group.
The results of the study, which was also published on the website of Genetic Literacy Project, only strengthens the belief that mutations in some genes play a big factor in the skewed sex ratio of autism. The condition is more likely to happen in 5 boys for every girl. This may be attributed to the fact that girls may need a bigger genetic hit for the features to autism to show up. Likewise, autism is easier to detect in boys than in girls.
