Hereditary mixed polyposis syndrome
Ballester-Vargas V., Tomlinson I.
© Springer International Publishing Switzerland 2016. Hereditary mixed polyposis syndrome is an autosomal dominant condition characterized by colonic polyps of more than one histopathological type, including atypical juvenile polyps, adenomas, and hyperplastic polyps. Affected individuals do not always present with a characteristic clinical phenotype. Upper gastrointestinal and extracolonic features found in other hereditary cancer syndromes are not present. Individuals affected with this syndrome have a predisposition to develop CRC at an early age, and therefore screening and surveillance at an early age are warranted. Affected individuals are generally of Ashkenazi descent and carry a germline duplication of about 40 kb upstream of the GREM1 gene. This chapter will highlight the clinical and molecular features of HMPS and recommendations for the management of patients and their families.