In the context of our investigation, we have discerned the presence of PVs, LPs, or VUSs of the genes ATM, BARD1, BRCA1, BRCA2, BRIP1, CDH1, CHEK2, MLH1, MSH2, MSH6, MUTYH, NF1, PALB2, PMS2, PTEN, RAD51C, RAD51D, RAD54L, STK11, and TP53 among BC patients residing in the southernmost region of Thailand. The gene discussed is MLH1; the disease is breast cancer.