A new study has identified a sex-chromosome-linked gene that drives inflammation in the female brain, offering insight into why women are disproportionately affected by conditions such as multiple sclerosis. The findings offer a potential target for intervention.

The University of California – Los Angeles Health Sciences researchers used a mouse model of MS to identify a gene on the X chromosome that drives inflammation in brain immune cells, known as microglia. Because females have two X chromosomes, as opposed to only one in males, they get a “double dose” of inflammation, which plays a major role in aging and MS.

When the gene, known as Kdm6a, and its associated protein were deactivated, the MS-like disease and neuropathology were both ameliorated with high significance in female mice.

When researchers genetically “knocked out” the Kdm6a gene in brain immune cells, the inflammatory molecules shifted from being activated to a resting state. Additionally, the team performed a pharmacologic "knock down" of the protein made by this gene using metformin, which is widely used as a treatment for diabetes.

While these interventions were highly significant in female mice, their effect was almost undetectable in males, researchers said. They said the findings may also have implications for explaining a connection to brain fog in healthy women during menopause.

Results of mouse model studies sometimes do not translate to humans and may be years away from being a marketable treatment. However, the authors said these findings may support the use of estrogens that target the brain to keep the balance, and thereby protect the brain, during menopause.

The findings were published in the journal Science Translational Medicine.