Physicians newspaper, 07.11.2018
Researchers have found a possible explanation for the higher risk of autism in boys.
Gender Difference: Autism is four times more common in boys than girls.
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HEIDELBERG. Autism is known to occur four times more frequently in boys than girls. Scientists have now found a possible explanation, says the University of Heidelberg.
Their studies in human cells and brain areas in mice have shown that testosterone activates certain risk genes in the brain significantly more in the period before and after birth (Front Mol Neurosci 2018, online September 25, and on-line July 19).
So far it has only been known that the defects of these so-called SHANK genes are a strong risk factor for the development of autism. New results suggest that these genetic defects may have a greater effect on the brains of men than women.
For their study, the neuroblastoma cell culture was used as a model for nerve cell development.
Higher levels of Shank protein in male mice
Scientists have discovered in these cells that activation of the SHANK genes depends on the binding of testosterone to the androgen receptor. When this receptor was blocked, strong activation of the risky genes disappeared.
"We have been able to confirm this in studies in brain areas of young mice in which this androgen receptor is not produced, with these genes being activated much weaker than control animals with intact receptors," one of the authors said. Simone Berkel in a statement from the University Hospital.
Scientists also studied the amount of trace protein in the brains of young male and female mice before and after delivery. In men, significantly higher levels of Shank were found than in females.
"We assume that a greater amount of trace protein in the male brain increases the" punching force "of defects in SHANK genes, and therefore leads to a higher risk of autism," Professor Gudrun Rappold of the University of Zurich reported quoted. (EB)
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