gastrointestinal disorders
Lynch Syndrome
Introduction
Lynch syndrome is an autosomal dominant disorder responsible for 2 to 3% of cases of Colorectal Cancer ( Lynch syndrome is an autosomal dominant disorder in which patients have one of several known genetic mutations that impair DNA mismatch repair. Lynch syndrome confers a 70 to 80% lifetime risk of developing Colorectal Cancer (CRC) ( Compared to sporadic forms of colon cancer, Lynch syndrome occurs at a younger age (mid 40s), and the lesion is more likely to be proximal to the splenic flexure. The precursor lesion is usually a single colonic adenoma, unlike the multiple adenomas present in patients with Familial Adenomatous Polyposis , the other main hereditary form of CRC. However, similar to familial adenomatous polyposis, numerous extracolonic manifestations occur. Nonmalignant disorders include café-au-lait spots and sebaceous gland tumors. The low-grade skin cancer, Keratoacanthoma , can occur. Other common associated cancers include 