Table 6.

Genetic polymorphisms in DNA mismatch repair genes that influence the risk of developing esophageal carcinoma in South Africa and China

Mutation	OR	Effect on ESCC risk
South Africa
G/G vs A/A or A/G genotype polymorphism in MSH3 rs2627973	2.71 at 95% CI	Allied with increased ESCC susceptibility in mixed ancestry South Africans
G-allele in PMS1 rs5742938 polymorphism (GG vs AA or AG)73	1.73 at 95% CI	Allied with increased ESCC susceptibility in mixed ancestry South Africans
A-allele in MLH3 rs28756991 polymorphism (AA or GA vs GG) Arg797His73	2.07 at 95% CI	Allied with increased ESCC susceptibility in mixed ancestry South Africans. Compromises the structure and function of MLH3 protein. The ternary complex formed between heterodimers MSH2–MSH3 and MLH1–PMS1 is a critical incident in ESCC development
China
DNA mismatch repair gene MSH2 (MSH2c.2063G)153	3.36 at 95% CI	Polymorphisms increase the risk for EC
DNA mismatch repair gene MLH1 (MLH1IVS14-19G)153	1.70 at 95% CI	Polymorphisms increase the risk for EC
DNA lesion repair enzyme MGMT gene MGMT Rs11016879152,153 AA vs GG AG vs GG Rs12771882 AA vs GG Rs7075748 (CT vs CC) Rs11016878 AG vs AA Rs7069143 CT vs CC Rs7071825 GG vs AA	At 95% CI 3.11 3.93 2.44 1.95 0.39 0.48 0.49	Some polymorphisms in the gene lead to increased risk of developing ESCC, while others have a protective function decreasing the risk for ESCC
MGMT153 A allele Rs10734088 C allele Rs475111	At 95% CI 1.97 2.18	Significantly increase the risk for developing ESCC
MGMT A allele Rs2053139153	0.51 at 95% CI	Associated with a protective effect on ESCC progression
MGMT C allele Rs7068306152,153	2.20 at 95% CI	Increased risk of ESCC metastasis
WRN gene215 (WRN c.4330TC)	2.21 at 95% CI	Significantly increased risk for developing ESCC

Note: The table describes genetic polymorphisms in DNA repair pathway genes that are found in South African and Chinese populations.

Abbreviations: ESCC, esophageal squamous cell carcinoma; rs, Reference SNP cluster ID; SNP, single-nucleotide polymorphism.