MLH1 and cancer: MTS is a rare autosomal dominant disease in which there is a mutation in a DNA mismatch repair gene (MLH-1, MSH-2, MSH-6, PMS1 Homolog 2 and PMS-2),4, 6, 7 characterized by the presence of benign or malignant neoplasms originating in sebaceous glands that may or may not occur concomitantly with other malignant neoplasms, especially of the gastrointestinal tract and genitourinary system, the most common being colorectal cancer (80% of cases).