Nature Genetics: Your genes determine whether you have ADHD or autism

The researchers have now identified seven genetic variants that are common in both autism and hyperactivity, and five that target only one of the two diagnoses

Professor Anders Börglum of the Department of Biomedical Sciences at Aarhus University and iPSYCH said: "We have successfully identified common genetic risk variants and genetic variants

"It means that we are beginning to understand the biological processes behind both diagnoses, and – as something entirely new – that propels developmental disorders in the direction of autism or hyperactivity

Genetic variants affect nerve cells in the brain and how the brain develops and

Specifically, for example, researchers can see that some genetic variants that only increase the risk of autism also increase an individual's cognitive function, while complementary variants that only increase the risk of ADHD generally reduce an individual's cognitive function

Similarly, researchers have discovered a genetic variant that increases the risk of developing autism while reducing the volume of a particular brain region in the general population, while complementary variants increase the risk of ADHD and increase the volume

This may seem obvious, but this study is the first in the world to show that people with both ADHD and autism have a double burden on genetic risk because they have both diagnoses, and people with only one diagnosis largely bear only the genetic risk variant

This means, for example, that people with both diagnoses have as many ADHD genetic factors as people with only ADHD, and as many genetic factors

The researchers analyzed a large dataset of gene maps to learn more about diseases and developmental disorders

Diagnosis of autism is usually made before the diagnosis of ADHD

"But if we do genetic studies on a person who has been diagnosed with autism and we're going to see a major genetic load then we probably should monitor that person

A few years ago, he said, it was impossible in principle to diagnose attention deficit hyperactivity disorder

"But now we've shown that people with both diseases actually carry a genetic risk

"This is the first step
.
At this moment, the study is relevant because it helps to better understand the causes of these two developmental disorders, which could form the basis for better diagnosis and treatment in
the long run.
”

• The study examined genetic variants in the genomes of 34462 patients diagnosed with autism spectrum disorder and/or ADHD, as well as 41,201 control groups that were not diagnosed with autism (so-called ADHD, genome-wide association study).
  For each person, 8.
  9 million recurring genetic variants have been tested, and they are distributed throughout the
  genome.
  

• By correlating genetic outcomes with data on the expression of genes in different regions of the brain and brain cells, such as in so-called brain transcriptome-related studies (TWAS), researchers can examine the consequences
  of various genetic risk variants.
  

• The researchers gained more information
  about the significance of genetic risk variation by comparing the results of autism/ADHD analysis with genetic findings of other mental disorders and general traits such as cognitive function and brain region volume.
  

• The study was led by researchers at iPSYCH Denmark and many international partners in the Psychiatric Genomics Consortium (PGC) and the Broad Institute of Massachusetts and Harvard.
  

• iPSYCH is primarily funded by the Lundbeck Foundation
  .
  

Identification of shared and differentiating genetic architecture for autism spectrum disorder, attention-deficit hyperactivity disorder and case subgroups