The number of multiple sclerosis (MS) patients seems to be increasing faster among women than men. According to a latest study, women with MS are more likely to have a gene linked with multiple sclerosis than men with the disease. It is this gene region where environment possibly interacts with the genetics.

Scientists evaluated the HLA genes of 1,055 families with more than one person suffering from MS in the family. The genes of 7,093 people were tested among which 2,127 had MS. The study also looked at what the HLA genes were for people with and without MS, whether people with MS inherited the susceptibility gene from their mother or father, and what the relationship was between people in the same family with MS. Women with MS apparently were 1.4 times more likely to have the HLA gene variant associated with MS than men. 919 women and 302 men with the HLA gene variant were compared to 626 women and 280 men who did not have the gene variant.

Investigators observed an epigenetic mechanism, wherein the environment interacted with the gene region. Women with the HLA gene variant probably face a higher chance of transmitting the gene variant to other women in their families than men. Second-degree relatives like aunts and their nieces or nephews may have a greater likelihood of inheriting the gene variant than first-degree relatives such as siblings or parents and children. George C. Ebers, MD, FMedSCi, of the University of Oxford in the United Kingdom and a member of the American Academy of Neurology, study author and colleagues affirm that the less the genetic sharing between individuals, higher the interaction appears between female sex and inheritance of the HLA gene variant.

The study is published in the January 5, 2011, online issue of Neurology, the medical journal of the American Academy of Neurology.