Association of 4p14 and 6q27 variation with Graves disease: a case-control study and a meta-analysis of available evidence.

BACKGROUND: The etiology of the Graves' disease (GD) is largely unknown. However, genetic factors are believed to play a major role. A recent genome-wide association study in a Han Chinese sample collection revealed two new Graves' disease (GD) risk loci within chromosome band 4p14 and 6q27. In this study, we aimed to investigate these associations with Weifang Han Chinese population of Shandong province and perform a meta-analysis of associations with GD. METHODS: A case-control study was conducted to investigate association of variation within 4p14 and 6q27 to GD susceptibility in Weifang Han Chinese population of Shandong province. SNP rs6832151 at chromosome 4p14 and SNP rs9355610 at chromosome 6q27 was selected for genotyping in 2,382 GD patients and 3,092 unrelated controls. SNP genotyping was performed using TaqMan Real-time PCR technique assays on ABI7900 platform. A meta-analysis was performed with the data obtained in the current sample-set and those available from prior studies. RESULTS: Association analysis revealed both rs6832151 located in 4p14 (odds ratio (OR) = 1.27, P Allelic = 1.48 × 10-9) and rs9355610 located in 6q27 (OR = 1.10, P Allelic = 1.04 × 10-2) was associated with GD susceptibility. By model of inheritance analysis, we found the recessive model should be preferred (P Recessive = 2.75 × 10-11) for rs6832151. The dominant model should be preferred (P Dominant = 7.15 × 10-3) for rs9355610, whereas analysis of recessive model showed no significant association (P Recessive = 0.13). Meta-analysis with the data of 10,781 cases and 16,304 controls obtained from present sample-set and those available from prior studies confirmed association of rs6832151 at 4p14 with GD susceptibility using a fixed model (OR = 1.27, 95% CI: 1.22 to 1.32; I2 = 0%). Meta-analysis with the data of 11,306 cases and 12,756 controls confirmed association of rs9355610 at 6q27 with GD susceptibility using a fixed model (OR = 1.18, 95% CI: 1.13 to 1.22; I2 = 41.2%). CONCLUSIONS: Our findings showed that chromosome 4p14 and 6q27 variants were associated with Graves' disease in Weifang Han Chinese population of Shandong province.