UCLA scientists find male gene in brain area targeted by Parkinson’s

“Men are 1.5 times more likely to develop Parkinson’s disease than women,” said Dr Eric Vilain, associate professor of human genetics at the David Geffen School of Medicine at UCLA. “Our findings may offer new clues to how the disorder affects men and women differently, and shed light on why men are more susceptible to the disease.”

In 1990, British researchers identified SRY as the gene that determines gender and makes embryos male. Located on the male sex chromosome, SRY manufactures a protein that is secreted by cells in the testes.

Now, in an unexpected discovery, Dr Vilain’s team became the first to trace the SRY protein to a region of the brain called the substantia nigra, which deteriorates in Parkinson’s disease.

Parkinson’s disease occurs when cells in the substantia nigra begin to malfunction and die. These brain cells produce a neurotransmitter called dopamine that communicates with the brain areas controlling movement and coordination. As the cells die off, they produce less dopamine. This slows the delivery of messages from the brain to the rest of the body, leaving the person unable to initiate or control their physical movements. The condition eventually leads to paralysis.

“For the first time, we’ve discovered that the brain cells that produce dopamine depend upon a sex-specific gene to function properly,” Dr Vilain said. “We’ve also shown that SRY plays a central role not just in the male genitals, but also in regulating the brain.”

Dr Vilain believes that variations in SRY levels may be linked to the onset of Parkinson’s and could offer insights into who is at risk for the disease.

“SRY may serve as a protective agent against Parkinson’s,” suggested Dr Vilain. “Men who contract the disease may have lower levels of the gene in the brain.”

Sex differences in other dopamine-linked disorders, such as schizophrenia or addiction, may also be explained by the SRY gene, Dr Vilain said.