Mtr, also known as methionine synthase, is a key enzyme in homocysteine metabolism. It plays a crucial role in the remethylation of homocysteine to methionine, which is involved in important biological processes such as DNA methylation, protein synthesis, and cell growth [1,2,3,4].

Genetic polymorphisms of Mtr, like the A2756G and D919G variants, have been studied in relation to various diseases. The MTR A2756G polymorphism might be a potential risk factor for male infertility, with significant associations found in certain genetic models [3]. The MTR D919G variant is associated with an increased risk of prostate adenocarcinoma, especially in Asian descendants and hospital-based studies [4]. Also, the G allele of Mtr is a high-risk factor for lower-extremity arteriosclerotic occlusion [1]. In contrast, the MTR A2756G genetic polymorphism was not associated with the risk of recurrent miscarriages [2].

In conclusion, Mtr is essential in homocysteine metabolism. Genetic studies of Mtr polymorphisms have revealed its associations with male infertility, prostate adenocarcinoma, and lower-extremity arteriosclerotic occlusion. Understanding Mtr's role through these genetic models can provide insights into the mechanisms underlying these diseases, potentially leading to new preventive and treatment strategies.