The rs2609255 polymorphism in the FAM13A gene is reproducibly associated with silicosis susceptibility in a Chinese population

Background: Two recent genome-wide association studies (GWASs) reported that the FAM13A gene at the 4q22 locus associated with pulmonary fibrosis (defined by rs2609255) overlapping with COPD (defined by rs6837671). We hypothesized that single-nucleotide polymorphisms (SNPs) related to lung disease (especially pulmonary fibrosis) identified in this region are also associated with the risk of silicosis. Methods: To test this hypothesis, we genotyped these two SNPs (rs2609255 and rs6837671) in a case-control study including 177 silicosis cases and 204 controls with silica dust exposure years similar to the levels for cases in a Chinese population. Results: We found that rs2609255 was significantly associated with increased silicosis risk (dominant model: OR = 1.71; 95% CI = 1.01-2.92; P = 0.047). Additionally, eQTL analysis based on the GTEx database indicated that the rs2609255 polymorphism may alter the expression level of FAM13A in lung tissues (P = 1.8 x 10(-4)). Furthermore, interaction analyses showed that rs2609255 interacts multiplicatively with years of silica dust exposure to contribute to silicosis risk (interaction P = 0.040). Conclusions: These results indicate that rs2609255 may modify silicosis susceptibility in the Chinese population.