Washington, Sep 9 (IANS): In men suffering from Autism Spectrum Disorders (ASDs), lower levels of the sex hormone estrogen may be related to changes in the brain's estrogen signalling, says an Indian-origin researcher.

To understand this, lead author Anilkumar Pillai from the Georgia Regents University examined the brains of people that had ASD and compared them with controls.

He found that the former are linked with far lower levels of a key estrogen receptor and other estrogen-related proteins.

"Our study is the first indicator that estrogen receptors in the brain of ASD patients may be different to controls," Pillai said.

Though this suggests a possible reason for the gender bias, we still need to determine what causes the reduced production of estrogen related proteins, he noted.

ASDs are a group of disorders that affect brain development and are commonly recognised by impaired social interaction, verbal and non-verbal communication and restricted and repetitive behaviour.

A team of researchers led by Pillai measured the expression of proteins involved in the estrogen signalling pathway in brain tissue from 13 people that had ASDs and 13 controls.

They looked for levels of ERI - an estrogen receptor molecule and aromatase - an enzyme which converts testosterone to estradiol, the most potent estrogen.

They found 35 percent less ERI mRNA and 38 percent less aromatase mRNA in autistic brain tissue in comparison with controls.

The lower levels of estrogen receptors and aromatase could lead to reduced conversion of testosterone to estradiol, resulting in increased levels of testosterone.

"It is worth looking at whether drugs which modulate estrogen reception, but do not cause feminisation, could allow for the long-term treatment of male patients with ASD," Pillai concluded.

The research was published in the journal Molecular Autism.