An intronic variant in SLC9A9 (rs9828519) is associated with nonresponse to interferon-β (INFβ) in patients with multiple sclerosis (MS), according to a genome-wide association study.
Researchers confirmed the association in a meta-analysis across 3 replication data sets and found the SLC9A9 mRNA expression is diminished in MS subjects who are more likely to have relapses.
In addition, SLC9A9 knockdown in T cells in vitro leads to an increase in expression of proinflammatory molecule IFNϒ.
Citation: Esposito F, Sorosina M, Ottoboni L, et al. A pharmacogenetic study implicates SLC9a9 in multiple sclerosis disease activity. Ann Neurol. 2015;78(1):115-127. doi: 10.1002/ana.24429.