Differential effects of genetic susceptibility factors in males and females with multiple sclerosis

• MS is more common in females than males.
• The rate of MS appears to be increasing in females compared to males.
• There are maternal effects on MS risk.
• Maternal effects can also influence HLA allele transmission.

Multiple sclerosis (MS), a putative autoimmune disease, has a well documented female preponderance among patients. However, this is not the only sex effect observed in the disease. Unaffected mothers appear to be at a higher risk to transmit susceptibility (genetic, environmental or interactions thereof) compared to unaffected fathers. This maternal effect can range from intrauterine exposures to transmission of genotypes and epigenetics.