TY - JOUR T1 - Lack of Interaction Between Systemic Lupus Erythematosus-associated Polymorphisms in <em>TYK2</em> and <em>IRF5</em> JF - The Journal of Rheumatology JO - J Rheumatol SP - 676 LP - 677 DO - 10.3899/jrheum.090823 VL - 37 IS - 3 AU - MARIAN SUAREZ-GESTAL AU - MANUEL CALAZA AU - ANTONIO GONZALEZ Y1 - 2010/03/01 UR - http://www.jrheum.org/content/37/3/676.2.abstract N2 - To the Editor:These are exciting times for the genetic investigation of systemic lupus erythematosus (SLE), characterized by the discovery of many reproducibly associated loci1. Further progress will require research in many different directions, including investigation of how the effects of each locus integrate between them and with environmental exposures to cause SLE. We read with interest the report by Hellquist, et al2 that showed evidence of significant epistatic interaction between 2 SLE-associated loci, IRF5 and TYK2. The first is a definitively confirmed SLE susceptibility locus with one of the strongest, albeit complex, effects. The latter has been more contentious, but its association with SLE is becoming clearer2,3. Epistasis means that risk in subjects with susceptibility alleles at the 2 loci significantly exceeds the sum of the risks at each locus. This was rightly interpreted to mean that the 2 loci impinge in the type 1 interferon pathway2, … Address correspondence to Dr. Gonzalez; E-mail: Antonio.Gonzalez.Martinez-Pedrayo{at}sergas.es ER -