Interplay between genetic and environmental risk factors in multiple sclerosis: what have we learned?

Genome-wide association studies (GWAS) have identified over 230 genetic variants associated with susceptibility to multiple sclerosis (MS) and one genome-wide significant variant associated with progression of MS. Environmental risk factors, such as vitamin D deficiency and obesity, have also been implicated in MS pathogenesis. Statistical approaches building on these genetic data, such as Mendelian randomization and colocalization, have established putative causal links between environmental ri