Miami, Florida–(ENEWSPF)–August 11, 2011. Scientists have identified 29 new genetic variants linked to multiple sclerosis, providing key insights into the biology of an important and very debilitating neurological disease. Many of the genes implicated in the study are relevant to the immune system, shedding light onto the immunological pathways that underlie the development of multiple sclerosis.
Researchers Margaret A. Pericak-Vance, Ph.D., and Jacob McCauley, Ph.D., at the John P. Hussman Institute for Human Genomics at the Miller School played an important role in this international effort. “We are seeing more and more genes, which we hope will lead to disease targets,” said Pericak-Vance, associate dean for Human Genomic Programs, Dr. John T. Macdonald Foundation Professor of Human Genomics and director of the John P. Hussman Institute for Human Genomics. “We hope that the identification of these new variants will one day lead to better treatment and diagnosis of this devastating disorder.”
The research, involving an international team of investigators and funded primarily by the Wellcome Trust, is published in the August 11 issue of the journal Nature. This is the largest MS genetics study ever undertaken and includes contributions from almost 250 researchers as members of the International Multiple Sclerosis Genetics Consortium and the Wellcome Trust Case Control Consortium.
In this multi-population study, researchers studied the DNA from 9,772 individuals with multiple sclerosis and 17,376 unrelated healthy controls. They were able to confirm 23 previously known genetic associations and identified a further 29 new genetic variants (and an additional five that are strongly suspected) conferring susceptibility to the disease.
Multiple sclerosis is one of the most common neurological conditions among young adults, affecting around 2.5 million individuals worldwide. The disease results from damage to nerve fibers and their protective insulation, the myelin sheath, in the brain and spinal cord. The affected pathways — responsible in health for everyday activities such as seeing, walking, feeling, thinking and controlling the bowel and bladder – are prevented from ‘firing’ properly and eventually are destroyed. The findings focus attention on the pivotal role of the immune system in causing the damage and help to explain the nature of the immune attack on the brain and spinal cord.
A large number of the genes implicated by these findings play pivotal roles in the workings of the immune system, specifically in the function of T-cells (one type of white blood cell responsible for mounting an immune response against foreign substances in the body but also involved in autoimmunity) as well as the activation of ‘interleukins’ (chemicals that ensure interactions between different types of immune cell). Interestingly, one third of the genes identified in this research have previously been implicated in other autoimmune diseases (such as Crohn’s Disease and Type 1 diabetes) indicating that, perhaps as expected, the same general processes occur in more than one type of autoimmune disease.
Previous research has suggested a link between vitamin D deficiency and an increased risk of multiple sclerosis. Along with the many genes that play a direct role in the immune system, the researchers identified two involved in the metabolism of vitamin D, providing additional insight into a possible link between genetic and environmental risk factors.