Gene Variant May Increase Risk of Multiple Sclerosis
Variants of GAL are more common among women, which may explain the high prevalence of multiple sclerosis.
Scientists recently discovered that men and women have different susceptibility to multiple sclerosis (MS) and disease progression based on genetic factors.
It is well known that MS is 2 to 3 times more common among women compared with men. This could potentially suggest that hormones could play a role in susceptibility to the disease, according to the National Multiple Sclerosis Society.
The link between gender and susceptibility to MS has been evaluated extensively by many scientists around the world, but there have not been any definitive answers about why women are more likely to develop the disease.
In a study published by the Journal of Neuroscience Research, scientists found an association between sex-specific variants of GAL, a gene that codes for the protein galanin, and MS.
Galanin is a neuropeptide that is highly expressed in the brain, spinal cord, and gut of many mammals, including humans. Galanin has been known to play a role in nociception, sleep regulation, cognition, eating, moods, and blood pressure, but the functional role of the protein is still primarily unknown.
Other recent studies have shown high levels of galanin in brain samples of patients with MS.
In the current study, scientists compared the prevalence of more active and less active variants of DNA sequences that control galanin expression among 111 patients with MS and 115 healthy patients.
Scientists did not discover any overall differences between groups, but they did discover significant changes when looking specifically at gender. They found a 2-fold decrease in the less active genetic variant in men in the control group compared with women in the same group, according to the study.
Additional research indicated that the less active genetic variant was linked to an increased susceptibility to the disease in men, but not in women. In men, the presence of this variant was linked to a delayed onset of MS.
The GAL variant also was seen to affect the rate of disease progression depending on the sex of the patient, according to the study. Women with the less active variant progressed faster compared with women who did not.
These findings suggest that looking at men and women separately may hold the key to improved MS treatments. Scientists should also not rely on findings from male animal models and male cells since looking at the female counterparts may show important genetic differences.
“We hope that our findings will foster development of a personalized strategy for the prevention and treatment of multiple sclerosis, one that takes into account the gender-specific contribution of galanin gene variants to susceptibility and disease progression,” said the study lead author Dr Victoria Lioudyno.