Rs6897932

The (C) allele of rs6897932, located in the alternatively spliced exon 6 of IL7RA gene and encoding the amino acid threonine rather than isoleucine at amino acid position 244, is associated with a slight increase (18%) in risk of developing multiple sclerosis. [PMID 17660817; Nature Genetics 39, 1083 - 1091 (2007) SG Gregory et al.]

Note that the (C) allele is the most common at this position in all known populations and influences the ratios of the alternative isoforms (membrane bound and soluble) of the gene.

blog post giving perspective on the significance of this snp

a significant risk factor for multiple sclerosis in four independent (overall P = 2.9 x 10(-7)) influences the amount of soluble and membrane-bound isoforms of the protein by putatively disrupting an exonic splicing silencer.

nejm C allele increasing the risk of multiple sclerosis (odds ratio, approximately 1.2)

A replication case-control study involving 599 Spanish patients with multiple sclerosis yielded a per allele odds ratio of 1.32 per rs6897932(C), (CI: 1.1-1.6, p = 0.0031), and odds per (C;C) genotype vs (T;T) and (C;T) genotypes of 1.5 (CI: 1.18-1.87, p = 0.0007).