Genome-Wide Association Study Reveals Distinct Genetic Susceptibility of Thyroid Nodules From Thyroid Cancer

Context: Thyroid nodules are very common, and 7% to 15% of them are diagnosed as thyroid cancer. However, the inherited genetic risk factors for thyroid nodules and their associations with thyroid cancer remain unknown. Objective: To identify the genetic variants associated with susceptibility to thyroid nodules in comparison with thyroid cancer. Design and Setting: We performed a three-stage genome-wide association study for thyroid nodules. The discovery stage involved a genome-wide scan of 811 subjects with thyroid nodules and 691 subjects with a normal thyroid from a population-based cohort. Replication studies were conducted in an additional 1981 cases and 3100 controls from the participants of a health checkup. We also performed expression quantitative trait loci analysis of public data. Results: The most robust association was observed in TRPM3 (rs4745021) in the joint analysis (OR, 1.26; P = 6.12 x 10(-8)) and meta-analysis (OR, 1.28; P = 2.11 x 10(-8)). Signals at MBIP/NKX2-1 were replicated but did not reach genome-wide significance in the joint analysis (rs2415317, P = 4.62 x 10(-5); rs944289, P = 8.68 x 10(-5)). The expression quantitative trait loci analysis showed that TRPM3 expression was associated with the rs4745021 genotype in thyroid tissues. Conclusions: To the best of our knowledge, we have performed the first genome-wide association study of thyroid nodules and identified a susceptibility locus associated with thyroid nodules, suggesting that thyroid nodules have a genetic predisposition distinct from that of thyroid cancer.