TYK2 and multiple sclerosis: Two of these variants (TYK2 p.Pro1104Ala, overall MAF 4.1% in our samples; GALC p.Asp84Asp, overall MAF 3.9%) are in regions identified by our latest MS GWAS and show linkage disequilibrium with the common-variant associations we have previously reported (International Multiple Sclerosis Genetics Consortium et al., 2011).