Genetic Variation of MLH1 (rs63749820) in Patients With Oral Squamous Cell Carcinoma

Oral squamous cell carcinoma (OSCC) is the most common type of cancer found in the oral cavity, exhibiting a persistent increase in incidence in developing nations. The mismatch repair (MMR) system preserves genomic stability during successive duplications. Mutator L Homolog 1 (MLH1) is a crucial component of the MMR and significantly contributes to mutation prevention. This study sought to evaluate the genetic variation of MLH1 (rs63749820) in patients with OSCC.

A total of 201 individuals were enrolled in the study, consisting of 101 patients diagnosed with OSCC and 100 control subjects. The MLH1 variant rs63749820 was identified using tetra-primer amplification-refractory mutation system-polymerase chain reaction (ARMS-PCR).

Multivariate logistic regression analysis revealed that, within the codominant model, individuals carrying the TT genotype exhibited a significantly reduced risk of OSCC, with the odds ratio (OR) decreasing to 0.35 relative to those with the CC genotype (OR = 0.35, 95% CI = 0.15-0.81, and p = 0.01). In the prevailing model, the risk of OSCC was significantly reduced to 0.51-fold in patients with TT + CT genotypes of rs63749820 compared to the CC genotype (OR = 0.48, 95% CI = 0.24-0.95, and p = 0.03). The T allele was notably less prevalent in OSCC patients (44.05%) than in controls (56%) (p = 0.01). No substantial differences were noted between clinicopathological characteristics and genotype.

This research demonstrated a correlation between genetic variants in MLH1 and the risk of OSCC within the Iranian population. The TT, rather than CT, is the key genotype conferring reduced susceptibility to OSCC in this population.