# Single-Nucleotide Polymorphisms of BRCA1 and BRCA2 and Risk of Papillary Thyroid Carcinoma

## TL;DR

This study found that certain genetic variations in the BRCA1 gene are linked to a lower risk of developing papillary thyroid cancer in the Korean population.

## Contribution

The study identifies specific BRCA1 SNPs and haplotypes associated with reduced susceptibility to papillary thyroid carcinoma in Koreans.

## Key findings

- BRCA1 SNPs rs8176318, rs1799966, rs16940, rs799917, and rs1799949 were significantly associated with reduced papillary thyroid carcinoma risk.
- Haplotypes of BRCA1, including rs8176318(C)-rs1799966(T)-rs799917(G)-rs16940(A)-rs1799949(G), were linked to decreased PTC risk.
- Certain genotypes of BRCA1 SNPs showed odds ratios of 0.67–0.70, indicating reduced cancer risk.

## Abstract

This study was conducted to analyze the association between genetic polymorphisms of breast cancer genes 1 (BRCA1) and 2 (BRCA2), which are well known for their association with breast cancer and the development of thyroid cancer. We analyzed the relationship between single-nucleotide polymorphisms (SNPs) in BRCA1 and BRCA2 and thyroid cancer and conducted a haplotype analysis of these polymorphisms to study the interactions between genetic polymorphisms. The results of this study show that polymorphisms of BRCA1 were significantly related to the susceptibility to papillary thyroid carcinoma in the Korean population.

Background/Objectives: We sought to evaluate the association between the risk of papillary thyroid carcinoma (PTC) and single-nucleotide polymorphisms (SNPs) of breast cancer genes 1 (BRCA1) and 2 (BRCA2). Methods: We prospectively recruited 515 cases with PTC and 296 controls without cancer. The genotypes of five BRCA1 SNPs (rs8176318, rs1799966, rs799917, rs16940, rs1799949) and three BRCA2 SNPs (rs15869, rs1799943, rs1799955) were determined using the TaqMan assay. We evaluated the association of haplotypes with the risk of PTC due to linkage disequilibrium (LD). Results: The five BRCA1 SNPs were significantly associated with the risk of PTC. The AC genotype of rs8176318 (OR = 0.69, p = 0.02) and the CT and CC genotypes of rs1799966 (OR = 0.70, p = 0.02 and OR = 0.67, p = 0.01, respectively) were associated with a decreased risk of PTC. The AG genotype of rs16940 (OR = 0.67, p = 0.01) and the AG genotypes of rs799917 and rs1799949 (both OR = 0.70, p = 0.02) decreased the risk of PTC. Haplotype 1 [rs8176318(C)-rs1799966(T)-rs799917(G)-rs16940(A)-rs1799949(G)] ± (OR = 0.69, p = 0.02) and haplotype 2 [rs8176318(A)-rs1799966(C)-rs799917(A)-rs16940(G)-rs1799949(A)] ± (OR = 0.71, p = 0.03) of BRCA1 reduced the risk of PTC. Conclusions: Our findings suggest that the polymorphisms of BRCA1 may contribute to the susceptibility to PTC in the Korean population.