DNA samples from 416 patients with clinically diagnosed generalized MG (231 with Abs to acetylcholine receptor, AChR-MG), 53 with Abs to muscle-specific kinase (MuSK-MG), 55 patients with no detectable Abs (SN-MG), 77 patients with thymoma (TAMG) and 293 healthy controls (HC) were genotyped for the SNP (PTPN22 R620W, C1858T, rs2476601).
We conclude that the common autoimmune polymorphism PTPN22 1858C/T may account for disease susceptibility in a subset of nonthymoma MG patients with anti-titin antibodies present.