Researchers in the USA looked at the genetic mapping of a cross reference of the population, including 431 people on the Autistic Spectrum, comparing them to 379 people without a diagnosis.
What they found was that people on the spectrum were predominantly without the “back up copies” of some gene pathways. This is commonly known as “deletion” in genetics.
Deletion happens in everyone’s gene pathways, which is part of the reason we are all different. The specific genetics deleted, have different effects, thus specific genes during deletion could prove to be a strong lead in the detection of autism and ASD.
There were on average more deletions in the group of people with an ASD diagnosis than compared to the control group. There was also more of a phenomenon called “miss-writing” which means that the rebuilding of the DNA differed slightly, which could lead to different neural pathways being built in the brain.
The paper, published in the American Journal of Human Genetics, and undertaken by a team from Mount Sinai pinpointed the problems may come during cell autophagy (when cells renew themselves).
Prof Joseph Buxbaum, who led the research team, said:
“This is the first finding that small deletions impacting one or two genes appear to be common in autism, and that these deletions contribute to risk of development of this disorder.
There is a good reason to believe that autophagy is really important for brain development because the brain produces many more synapses [connections through which brain cells communicate] than it needs, and the excess needs to be pruned back.”
Too many, or too few, synapses have the same effect of not making communication work very well. It could mean that some synaptic connections come in too late and may not solidify properly.”
Speaking to the BBC, Carol Povey, director of the Centre for Autism at the UK’s National Autistic Society said:
“The causes of autism are still being investigated.
“Many experts believe that the pattern of behaviour from which autism is diagnosed may not result from a single cause.
“There is strong evidence to suggest that autism can be caused by a variety of physical factors, all of which affect brain development.
“Genetic factors may be responsible for some forms of autism, but it is likely to have multiple genes responsible rather than a single gene.
“This study provides interesting insights into autism and genetic factors.
“More research needs to be done before any concrete conclusions can be drawn about the causes and what this might mean for future developments, so it will be interesting to see how this research is built on to further enhance our knowledge of the condition.”