Further evidence of testosterone link to autism
A new study from Perth's The Kids for Child Health Research has uncovered more evidence of a link between early testosterone levels and autism.
The research team, led by Dr Andrew Whitehouse, used data from the long running Raine Study to examine the relationship between autism-like behaviours in early childhood among otherwise typically developing girls and the timing of their first period.
The results, published in the Journal of Autism and Developmental Disorders, found that girls with autism-like symptoms such as poor eye contact and repetitive behaviours were older at the time of their first period.
Dr Whitehouse says this finding may represent an important piece of the puzzle in understanding the causal influence on autism.
"The findings suggest that there may be a common developmental mechanism underlying both autism and the later onset of puberty." Dr Whitehouse said.
"One possible explanation relates to levels of testosterone in the womb. We know that autism affects more boys than girls. This has led to the idea that exposure to enhanced levels of testosterone in-utero may contribute to autism."
A girl's first period typically occurs between 12 and 13 years of age in most developed countries. The timing of the first-period is known to be regulated by both genetic and environmental factors, including race and body mass index. Importantly, prenatal exposure to testosterone is another factor thought to influence the age of a girl's first period.
"These findings indicate that exposure 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," Dr Whitehouse said.
This study is in line with previous findings by Dr Whitehouse and his team, which has shown a positive association between concentrations of testosterone taken from umbilical cord blood and autism-like symptoms in 10 year old children.
About the Raine Study
The Raine Study is jointly conducted by The Kids for Child Health Research and The School of Women's and Infant's Health at the University of Western Australia. The study started in 1989, when 2900 pregnant women were recruited into a research study at King Edward Memorial Hospital to examine ultrasound imaging. The mothers were assessed during pregnancy when information was collected on the mother and the father, for example diet, exercise, work, health, etc. The research team at The Kids for Child Health Research have assessed the children at 1, 2, 3, 5, 8, 10, 14 and 17 and now 20 years of age. Find out more at www.rainestudy.org.au