LS is the most common heritable cause of colorectal cancer and is associated with 10-48% cumulative risk of developing colorectal cancer by the age of 75 years dependent on the mutated MMR gene (MLH1 48.3%, MSH2 46.6%, MSH6 20.3%, PMS2 10.4%) [48]. The gene discussed is MLH1; the disease is colorectal cancer.