The hypothesis that multiple sclerosis is a genetically enabled disease in which immune cells attack the nervous system has been confirmed through a human genome-wide study that will be announced in tomorrow’s edition of the New England Journal of Medicine.
Assuming further genetic and functional studies confirm these results, the risk factors for contracting MS will be laid squarely on the human leukocyte antigen (HLA) region of human chromosome 6, along with specific alleles (gene variations) in the interleukin-2 receptor alpha gene (IL2RA) and the interleukin-7 receptor alpha gene (IL7RA).
Alleles in the HLA region have been linked to several other autoimmune diseases, including rheumatoid arthritis, lupus, and ankylosing spondylitis. The HLA genes generally encode proteins that form part of the cell membrane and are therefore responsible for the body’s ability to differentiate between its own and foreign cells. They also affect antigen formation and therefore indirectly influence the functioning of an important group of immune cells known as T cells.
Impairment of regulatory T cells—also known as suppressor T cells—allows the body to attack its own tissues and is a major factor in multiple sclerosis and other autoimmune diseases.
