Genotype Phenotype Correlation In Familial Adenomatous Polyposis

Familial Adenomatous Polyposis (FAP) is an autosomal dominant inherited syndrome whereby affected individuals can have less than 100 adenomas (Attenuated Adenomatous Polyposis) to thousands of adenomas (Classic Familial Adenomatous Polyposis). The syndrome is also characterized by extracolonic manifestations such as fundic gland polyps, duodenal adenomas, desmoids tumors, thyroid cancer, osteomas, and congenital hypertrophied pigmented retinal epithelium among others. There are genotype and phenotype correlations noted in and these will be discussed in this chapter.