OBJECTIVE: Several candidate genes have been implicated in susceptibility for systemic lupus erythematosus (SLE), a complex autoimmune disease. The proposed genes include members of the type I interferon (IFN) pathway and genes involved in immunological defense functions. Our aim was to systematically replicate 6 such genes, TYK2, IRF5, CTLA4, PDCD1, FCGR2A, and NOD2. METHODS: Single-nucleotide polymorphisms in TYK2, IRF5, CTLA4, PDCD1, FCGR2A, and NOD2 were genotyped in 277 SLE patients and 356 healthy controls from Finland, giving a power of 42%-70% for different genes at published allele frequencies. RESULTS: Significant association was seen for rs2304256 (p = 0.0001) and rs12720270 (p = 0.0031) in TYK2 and rs10954213 (p = 0.0043) in IRF5 in our samples, but not for the other genes. We found evidence for genetic interaction (p = 0.014) between rs2304256 in TYK2 and rs10954213 in IRF5, both members of the type I IFN pathway, strengthening the role of the type I IFN pathway in the pathogenesis of SLE. CONCLUSION: The IFN pathway genes IRF5 and TYK2 may act epistatically in increasing risk for SLE, but our lack of replication does not exclude effects of the other genes studied.
OBJECTIVE: Several candidate genes have been implicated in susceptibility for systemic lupus erythematosus (SLE), a complex autoimmune disease. The proposed genes include members of the type I interferon (IFN) pathway and genes involved in immunological defense functions. Our aim was to systematically replicate 6 such genes, TYK2, IRF5, CTLA4, PDCD1, FCGR2A, and NOD2. METHODS: Single-nucleotide polymorphisms in TYK2, IRF5, CTLA4, PDCD1, FCGR2A, and NOD2 were genotyped in 277 SLEpatients and 356 healthy controls from Finland, giving a power of 42%-70% for different genes at published allele frequencies. RESULTS: Significant association was seen for rs2304256 (p = 0.0001) and rs12720270 (p = 0.0031) in TYK2 and rs10954213 (p = 0.0043) in IRF5 in our samples, but not for the other genes. We found evidence for genetic interaction (p = 0.014) between rs2304256 in TYK2 and rs10954213 in IRF5, both members of the type I IFN pathway, strengthening the role of the type I IFN pathway in the pathogenesis of SLE. CONCLUSION: The IFN pathway genes IRF5 and TYK2 may act epistatically in increasing risk for SLE, but our lack of replication does not exclude effects of the other genes studied.
Authors: Travis Hughes; Adam Adler; Jennifer A Kelly; Kenneth M Kaufman; Adrienne H Williams; Carl D Langefeld; Elizabeth E Brown; Graciela S Alarcón; Robert P Kimberly; Jeffrey C Edberg; Rosalind Ramsey-Goldman; Michelle Petri; Susan A Boackle; Anne M Stevens; John D Reveille; Elena Sanchez; Javier Martín; Timothy B Niewold; Luis M Vilá; R Hal Scofield; Gary S Gilkeson; Patrick M Gaffney; Lindsey A Criswell; Kathy L Moser; Joan T Merrill; Chaim O Jacob; Betty P Tsao; Judith A James; Timothy J Vyse; Marta E Alarcón-Riquelme; John B Harley; Bruce C Richardson; Amr H Sawalha Journal: Arthritis Rheum Date: 2012-02