Autistic people with a rare genetic mutation tend to have a lower QI. This is what emerges from a study led by Matthew Jensen of the State University of Pennsylvania.
About 40% of those who suffer from condition also have intellectual disabilities. It is therefore difficult to distinguish autogenous genes from those that influence intelligence. Researchers were looking for genetic mutations of the genus common to people with autism. They have thus identified a common anomaly in these patients, but rare in other people.
Jensen and colleagues measured the intellectual quotient and made the DNA test of 2,300 autistic children. Of these, approximately 288 had a genetic mutation at the level of a single letter, not present in parents or brothers. In addition, 81 were devoid of a large piece of DNA. Children with these mutations had a much lower intellectual intellect than average.
Among the examined children, 397 had an intellectual rating above the average. The DNA test showed that almost none of them had the mutations in question. In addition, many of them did not even have the genetic mutations most commonly associated with autism. This means that these anomalies may cause a more severe form of autism, linked to intellectional deficits.
The discovery confirms the results of some previous studies, including one of 2014 conducted by Professor Mark Daly. The study showed that autistic children with low QI had a higher rate of genetic mutations.