Genetics

Scientists have long noticed that while women are more likely to develop multiple sclerosis, men often experience a faster and more aggressive decline—yet the biological reasons behind this disparity have remained elusive. A new study sheds light on a compelling piece of that puzzle: a variant in the PLXNA3 gene, located on the X chromosome, that appears to worsen disease severity specifically in men. Even more intriguing, the research suggests that women may be naturally protected by higher estradiol levels, which dampen the gene’s harmful effects. This blog post breaks down the study’s findings in clear, human terms—and explores what they could mean for the future of personalized MS care.