Some children with autism are carriers of rare genetic mutations inherited from their father. This is revealed by a study by the Beyster Center for Genomics and Neuropyschiatric Diseases. The discovery goes against the results of other studies, which attribute the genetic causes of autism to maternal heritage.
Researchers analyzed the genetic makeup of 9,274 individuals, including 311 families with at least one autistic child. They then analyzed the genome of 518 autistic individuals and their healthy relatives. In doing so, they focused on structural chromosomal abnormalities, such as deletions or duplications. In particular, they analyzed non-coding regions, determining in the expression of some genes.
Sequencing has unveiled structural variants in over 100 sections of DNA, for an average of 3,700 variations per person. Furthermore, autistic children had a high percentage of genetic variants inherited from their father. The researchers calculated that they were about twice the average. On the other hand, the anomalies inherited from the maternal side and linked to autism were a minimal percentage.
Sebat and colleagues published the first part of the study in March 2017. They later validated the results with DNA sequencing of 1,771 families with at least one autistic child.
The work contradicts the results of two other studies. Neither team had identified inheritable structural variants related to autism in non-coding regions. On the contrary, one of the two groups had linked autism to genetic mutations de novo, therefore not inherited.
The differences could be related to the algorithms used for DNA analysis. The three teams have also based on different and difficult to compare work methods. This means that in order to have clearer results, much broader studies will be needed that challenge all three responses.