GWAS Reveals Shared Susceptibility Locus Between RA and SLE Save

While the phenotypes of RA and SLE are quite different, genome-wide association studies (GWAS) performed in the past have shown a genetic overlap between both.

Gene expression studies have revealed common molecular mechanisms involved in the pathogenesis of these two conditions, which may explain a phenomenon of RA/SLE overlap, commonly known as rhupus.

To date, no comprehensive large-scale analysis of the genetic overlap between RA and SLE has been performed.

A group of multinational researchers have performed a large-scale meta-analysis of GWAS data from RA (3911 cases and 4083 controls) and SLE (2237 cases and 6315 controls) patients to identify risk loci shared between RA and SLE.

They identified the rs9603612 polymorphism, near COG6, achieved genome-wide significance in the combined analysis. This same locus was previously shown to be an established susceptibility locus for RA.

This study represents the first comprehensive large-scale analysis that highlights the existence of a relevant genetic correlation between RA and SLE as well as the influence of common molecular mechanisms in their pathophysiology.

Since common genetic pathways are implicated in RA and SLE, a reclassification of patients from a genetic point of view may lead to more specific and effective therapeutic strategies.