PERTH researchers have uncovered further evidence of a link between testosterone and autism, backing a theory that high testosterone exposure in the womb increases the risk of the disorder.
Researchers at Fiona Stanley’s Telethon Institute for Child Health Research found that girls with autistic-like behaviours at age two had their first period about six months later than girls without the disorder’s symptoms.
“These findings indicate that exposure to testosterone in the womb may be regulating both autism-like behaviours and the age of first period and that this may play a role in clinical autism,” lead researcher Andrew Whitehouse said.
He said the findings were linked to the so-called “male brain theory” of autism, which suggests the behaviour disorder is an extreme form of male mental traits.
“Autism is a real male-dominated condition; it affects around four males to one female, but there are also characteristics of people with autism that are more male-like,” he said. “People have started thinking what might cause that, and the obvious candidate is male-type hormones and the most biologically active is testosterone.”
The study looked at 383 girls who had no diagnosis of autism. At age two they were each given a rating for showing autistic-like behaviours such as avoiding looking people in the eye.
Perth mother Joanna Granich, whose five-year-old son, Louis, is autistic, said discovering causes of the disorder was vital.
“We don’t know what causes it at this point,” she said. “We need to better understand how autism is developed.”
Dr Whitehouse and his team are now embarking on a world-first study to further examine the link. In utero testosterone levels will be tested in pregnant women who already have an autistic child.
The levels will be compared with a control group of pregnant women who do not have a history of autistic children.
The institute is keen to hear from pregnant mothers who already have an autistic child who want to participate in the study.
Ms Granich, who is also a researcher at the institute, said throughout her second pregnancy with three-year-old son Isaac, she was worried he would also be autistic.
“You almost live in fear and you hope they’re not,” she said.
She said her dream for Louis was for him to be able to have a normal life and contribute to society.
Debbie Guest
The Australian