A new study has discovered there are different biological types of autism, with genetics, the immune system and the environment all thought to be factors in causing the varied forms.
A study of 350 children in the US found two biologically different types of brain development in autism and concluded that there are likely to be more.
Dr David Amaral, the head of the Autism Phenome Project at the University of California, says the study found the brains of some boys with autism "get too large, too soon".
"We don't see it in girls, and even in boys we see it only in a subset of children with autism," he said.
He says in biological terms there are different types of autism, but they all have similar symptoms.
"That's one of the mysteries at this point. We know that there are different biologies but that the behavioural symptoms of children with autism all look basically the same," he said.
"Many, many people now are trying to figure out whether all of these various biological causes are focusing on one final common pathway."
He says as research progresses, one form of autism might be more easily treated than others.
"As one example, about 12 per cent of women who have children with autism have antibodies that are directed at the foetal brain," Dr Amaral said.
"We're doing research now to determine whether that really is a cause. And if that's the case, that leads directly to a diagnostic marker for a subset of families that are going to go on to have children with autism.
Amaral predicted there would be many more biological subtypes of autism identified just as there were many forms of cancer. "If we were trying to cure all cancer at the same time, it would be hopeless," he said. "Well, the same is true for autism. My guess is that there just isn't going to be a single diagnostic marker for autism -- there's going to be a whole panel."
In a world first, Perth researchers will screen unborn babies for autism risks in the hope children can be treated earlier.
The team, headed by Telethon Institute for Child Health Research senior research fellow Andrew Whitehouse, will monitor 100 pregnant women who have a child with autism and 100 women who have a child with normal development.
At an international autism conference in Perth today [last Thursday], Dr Whitehouse will present research from another study showing abnormal levels of the hormone testosterone in umbilical cord blood are related to language impairment, a symptom of autism. In the next study over five years, his team will check foetuses for biomarkers linked to a higher risk of autism, including abnormal brain growth.
"Some of the genes linked to autism are responsible for aspects of neurodevelopment that happen very early on," Dr Whitehouse said.
Judi Barrett-Lennard, who is 32 weeks pregnant with her third child, is in the study. She and her husband were keen to support research that might find a cure for the condition that affected their seven-year-old son.
In the future, I can see different strains of autism being treated like cancer – powerful drugs attacking the problem. Except autism isn’t cancer and many people feel it to be an alternate reality rather than something to be eradicated.
Which brings us to the in utero screening for autism. How can this not spell pregnancy terminations for worried would be parents?
My conclusion is that we are perched on top of a very slippery slope in which “progress” will be judged subjectively by all the autism stakeholders.