The biggest genetic study of autism ever carried out shows that the genes that cause autism can also be found in the rest of the population. These genes are important for our ability to interact socially and communicate.

2016.04.27 | Mette Louise Ohana

Hereditary material from 38,000 people was scanned and compared to reach the result.

New research findings now confirm that the genes which form the basis for the development of autism are also to a high degree the same as important genes for social skills in the ordinary population. The genes influence the ability to communicate and interact socially with other people – and this also applies to people who are not autists. People with autism may simply have more of these risk genes and therefore exhibit a higher degree of these characteristics. An international research group with participants from Aarhus University and the Danish psychiatric research project iPSYCH are behind the study, which has just been published in the prestigious scientific journal Nature Genetics.

Tendency towards autism traits in some families

The results suggest that people have a high risk of developing autism if they have many genetic risk variants, while people with less of these are affected to a lesser extent.

"The new knowledge explains why we can see that family members of people with autism tend to have traits that are related to the disease. This also means that poor communication skills and a lack of a sense of social interaction can be inherited. There are, however, hundreds of genetic risk variants influencing the development of autism and it is only in particularly pronounced cases that the symptoms will be so extensive that autism will actually be diagnosed. This could be if the child inherits many of these risk genes from both parents or has perhaps received new gene mutations," says Anders Børglum, professor at the Department of Biomedicine at Aarhus University and one of the researchers behind the study.

In Denmark, around 1 out of 100 children are given an autism diagnosis. Heredity factors have a high degree of influence on autism – as much as eighty per cent.

Millions of genes scanned

The researchers have arrived at the result with the help of a genetic scan of the complete genome of more than 38,000 people, including 7,700 people with autism and 11,000 healthy control subjects from Denmark. This is the first time ever that DNA from such a large number of people with autism has been scanned.

"We have examined the genome in all of these people, whereby more than ten million genetic variants for each and every person was determined. The genetic profile from those with the disease was subsequently compared with the genetic profiles of the healthy subjects, so that we could identify the genes and genetic variants that are of significance for the development of the disease," says Jakob Grove, associate professor at the Department of Biomedicine at Aarhus University, who also participated in the study.

The psychiatric project iPSYCH is behind the Danish part of the study, which includes the world's largest genetic study of several psychiatric disorders including autism. iPSYCH is a collaboration between Aarhus University, the University of Copenhagen, and psychiatry services both the Central Denmark Region and the Capital Region of Denmark. The project also has a close collaboration with Statens Serum Institut and a number of foreign research institutions such as Broad Institute in the USA. The project is financed by the Lundbeck Foundation.

Read more

• Read the full scientific article "Genetic risk of autism spectrum disorders and neuropsychiatric variation in the general population" in Nature Genetics.
• Find out more about iPSYCH.

Further information

Professor Anders Børglum
Aarhus University, Department of Biomedicine
Mobile: (+45) 6020 2720
anders@biomed.au.dk