The variants showing significant differences between MS patients and HD were the following: rs10892307 (p = 1.37 × 10−6, OR = 0.77), located at the 5′ untranslated region (5′UTR) of CXCR5, two base pairs upstream from the start codon; rs2762943 (p = 0.047, OR = 1.16), located at the 5′ upstream region of the CYP24A1 gene, 672 base pairs upstream from the start codon; rs1599932 (p = 0.001, OR = 0.85), located in the TSFM gene within a region previously associated with MS susceptibility [16]; and rs3746821 (p = 0.03, OR = 1.15), an expression quantitative trait locus (eQTL) for the CD40 gene. This evidence concerns the gene CXCR5 and Huntington disease.