Genetics and pathogenesis of multiple sclerosis

Abstract

Multiple sclerosis (MS) is an idiopathic autoimmune neurodegenerative disease. Like many common diseases, MS has a genetic component; however, as with most complex diseases, the genetic architecture may be influenced by heterogeneity, incomplete penetrance, polygenic inheritance, and environmental factors. This clinically complex disease has provided great challenges for geneticists over the years. Although the first consistent genetic association to MS (with HLA-DR*1501) was discovered more than 30 years ago, lack of consistently replicated genetic results has plagued the scientific community. New study design methods (particularly genome-wide associations studies [GWAS]) along with genome project data and larger datasets have allowed several additional MS genes to be identified and consistently replicated. Thus, after many years of frustration, the strong genetic component associated with MS is finally beginning to be characterized.

Figure 1

Types of MS (left to right; top to bottom): relapsing-remitting, secondary progressive, primary progressive, and progressive relapsing (excerpt from All About Multiple Sclerosis, available at www.mult-sclerosis.org).

Figure 2

Lifetime risk of MS. (Reprinted from The Lancet, Volume 360, Issue 9333, Alastair Compston and Alasdair Coles, Multiple Sclerosis, Pages 1221–1231, 2002, with permission from Rightslink)