rs2235544

This prospective nested case-control study examined 17 single nucleotide polymorphisms related to free thyroxine (fT4) and thyroid peroxidase antibody (TPO-Ab) levels in 865 breast cancer cases and 3,193 controls from the Malmö Diet and Cancer Study. The main findings identified fT4-related SNPs rs2235544 (DIO1 gene, OR for breast cancer risk in low fT4 women) and rs6485050, as well as TPO-Ab-related SNPs rs11675434, rs3094228, rs1033662, rs301806, and rs2071403 as potentially associated with breast cancer risk. The most promising association was rs2235544 (DIO1), where the C allele was associated with lower fT4 levels and increased breast cancer risk, particularly in women with low fT4 levels, suggesting a potential causal relationship.

This candidate gene study examined 12 SNPs from genome-wide association studies of thyroid function in 1,555 subjects from three independent cohorts, testing associations with major depression and thyroid hormones. The authors confirmed that the DIO1 variant rs11206244 (T allele) was associated with increased free thyroxine (FT4) levels in both ethnic groups (p<0.004 in White females). Notably, rs11206244 genotype was associated with lifetime major depression in White female subjects from high-risk cohorts (p<0.004), but not in African American subjects or White males. Current FT4 levels were not associated with lifetime depression, suggesting thyroid changes in depression are state-dependent rather than trait-dependent.