14 DAY TRIAL // A new study supported by the Multiple Sclerosis Society of Canada and the Multiple Sclerosis Society of the United Kingdom, concluded that women who have multiple sclerosis (MS), are more likely to have the gene associated with the disease compared to men suffering from it, and it is in this gene region that environment interacts with genetics.
Nobody knows what the causes for MS are, but the existing evidence suggests that the disease is triggered by environmental factors in people who have a genetic predisposition to it.
For the study, the researchers looked at the HLA genes (the human leukocyte antigen class II gene is the main gene associated with MS) of 1,055 families that had more than one person with MS in the family.
They tested the genes of 7,093 people, including 2,127 people with MS, and analyzed the HLA genes in people with and without MS.
The researchers also verified whether people with MS inherited the susceptibility gene from their mother or their father, and what kind of relationship was between people in the same family with MS.
The results showed that women with MS were 1.4 times more likely than to have the HLA gene variant associated with MS than men with MS, or, in other words, out of the 2,127 people with MS, 919 women and 302 men had the HLA gene variant, compared to 626 women and 280 men who did not have the gene variant.
These new study results fit with previous research carried out by the same group, in which was shown that the environment interacts with this gene region to produce modification in risk associated with it.
The problem today is that, according to statistics, the number of people diagnosed with MS has been rising, and the rate increases faster for women than for men.
Besides the HLA gene, most of the risk comes from interaction of both parental genes.
Study author George C. Ebers, MD, Fellow of the United Kingdom Academy of Medical Sciences, of the University of Oxford in the United Kingdom and a member of the American Academy of Neurology, said that these “findings also show women with the HLA gene variant are more likely to transmit the gene variant to other women in their families than to men.
Furthermore, it seems that second-degree relatives like aunts and their nieces or nephews are more likely to inherit the gene variant than first-degree relatives such as siblings or parents and children.
Orhun Kantarci, MD, of the Mayo Clinic in Rochester, Minnesota, and a member of the American Academy of Neurology, wrote in an editorial on the study that “it appears that the less the genetic sharing between individuals, the higher the interaction is between female sex and inheritance of the HLA gene variant.
“These findings pave the way for future studies of these genes, hopefully to advance our understanding of inheritance of complex diseases such as MS.”
The study was published in the January 5, 2011, online issue of Neurology, the medical journal of the American Academy of Neurology.