Study finds new genetic variants associated with MS

Researchers have identified 29 new genetic variants with a link to multiple sclerosis (MS). This brings the total number of genetic changes associated with the disease, which affects around 2.5 million people worldwide, to nearly 50.

Researchers from the International Multiple Sclerosis Genetics Consortium analysed the genomes of 27,000 people, 9,772 of whom have the disorder. By looking at single letter changes in the DNA code, known as single nucleotide polymorphisms (SNPs) the researchers identified the 23 areas previously linked to MS as well as 29 new variants. The team, led by the University of Cambridge's Professor Alistair Compston, have also identified an additional five variants they strongly suspect will be involved.

'This is suddenly a big new number of genes to try to understand', Professor Compston told the BBC. 'Eighty percent of the genes that are implicated by the 57 'hits' are immunological. This shouts out that this is an immunological disease at the beginning. This is a very important confirmation'.

These results support the theory that MS is an autoimmune disease, where the body is attacked by its own defences. The disorder is caused by damage to the myelin sheath that surrounds and protects nerve cells in the central nervous system.

This genome wide association study (GWAS) is the largest analysis of people with MS, and it is hoped it will improve treatment of the disease. In fact, four of the gene variants discovered are related to drugs that are already on the market or in clinical trials.

Simon Gillespie, chief executive of the MS Society, who funded the project, said: 'By identifying which genes may trigger the development of MS, we can identify potential 'risk factors' and look at new ways of treating, or even preventing, the condition in the future'.

As these variants are associated with, but not located in, genes, further work is needed to establish their role in MS and how they interact with environmental factors. The researchers did not find variants that gave a clue as to the course of the disease, or how severe it would be.