Early onset of colorectal cancer in a 13-yearoldgirl with lynch syndrome

Abstract

Lynch syndrome is the most common inherited colon cancer syndrome. Patients with Lynch syndromedevelop a range of cancers including colorectal cancer (CRC) and carry a mutation on one of themismatched repair (MMR) genes. Although CRC usually occurs after the fourth decade in patients withLynch syndrome harboring a heterozygous MMR gene mutation, it can occur in children with Lynchsyndrome who have a compound heterozygous or homozygous MMR gene mutation. We report a caseof CRC in a 13-year-old patient with Lynch syndrome and congenital heart disease. This patient had aheterozygous mutation in MLH1 (an MMR gene), but no compound MMR gene defects, and a K-RASsomatic mutation in the cancer cells.