An international group of molecular biologists has found new evidence linking autism risk to non-coding DNA mutations. The study shows that autism spectrum disorder may be caused not only by changes in gene structure but also by mutations in non-coding regions of DNA.
According to a press release from The Hospital for Sick Children in Canada, "Our interdisciplinary research and experiments on mice showed that structural changes in non-coding regions of the genome can significantly affect brain function."
Over the past 20 years, geneticists have identified more than 100 gene variations that influence autism risk. Scientists from Canada, the USA, Europe, and South Korea investigated the impact of non-coding mutations on autism. They fully sequenced and compared the genomes of 9,300 individuals with autism and 8,300 healthy controls.
The study revealed that 27 males with autism shared a common genetic alteration: a shortened version of the PTCHD1-AS DNA segment on the X chromosome. This segment encodes a long RNA molecule that regulates genes affecting synaptic function. The team then tested the effect of the shortened PTCHD1-AS segment on mouse brains. Experiments showed that this DNA truncation led to autism-like behavioral changes and disrupted neuron synapse formation.
According to the World Health Organization (WHO), currently 1 in 100 children worldwide is diagnosed with autism spectrum disorder, and the rate is increasing annually.
