Old Suspects Found Guilty — The First Genome Profile of Multiple Sclerosis

High-resolution genomewide association studies using panels of 300,000 to 1 million single-nucleotide polymorphisms (SNPs) aim to define genetic risk profiles of common diseases. These studies herald a fundamentally new opportunity to explore human biology and medicine, since they are unbiased by previous hypotheses or assumptions about the nature of genes that influence complex diseases. Underscoring the importance of this approach is the fact that many genetic variants identified as risk factors in type 2 diabetes and Crohn's disease by such studies have been localized to previously unsuspected pathways, to genes without a known function, or to noncoding regions of genes.

In this issue of the Journal, Hafler and colleagues⁵ describe the outcome of the first effort of the International Multiple Sclerosis Genetics Consortium to define the genetic profile underlying a predisposition to multiple sclerosis. This large-scale association study, a joint analysis of an impressive data set of more than 12,000 subjects, supports the prediction of multiple risk alleles.