Objectives Serrated polyposis (hyperplastic polyposis) is characterized by multiple polyps with serrated architecture in the colorectum. While patients with serrated polyposis are known to be at increased risk of colorectal cancer (CRC) and possibly extracolonic cancers, cancer risks for their relatives have not been widely explored. The aim of this study was to estimate the risks of CRC and ex...

There have been significant advances in our knowledge about the molecular changes that precede and accompany the development of inherited predispositions to colorectal cancer. In this review the clinical relationship to the molecular changes associated with the polyposis syndromes is presented. The aim is to put into context the diverse findings that have been shown to be associated with the de...

A proportion of colorectal cancers shows some type of genetic predisposition that can be recognised in clinical practice. From the classical dominant inheritance pattern of familial adenomatous polyposis or hereditary non-polyposis colorectal cancer, through the recessive transmission of the MYH associated polyposis, to the new syndromes of the "serrated pathway" or low-penetrance alleles, the ...

Colorectal cancer is undoubtedly one of the most genetically studied malignancies. In the past 20 years, substantial progress has been made in understanding the genetic and molecular pathogenesis of this cancer. It is instructive that the genes involved in the inherited colon cancer syndromes are the same genes involved in the etiology of most colorectal cancers. Familial adenomatous polyposis ...

The genetic basis of sporadic colorectal cancer has illuminated our knowledge of human cancer genetics. This has been facilitated and catalyzed by an appreciation and deep understanding of the forms of colorectal cancer that harbor an inherited predisposition, including familial adenomatous polyposis (FAP), hereditary nonpolyposis colorectal cancer (HNPCC) or Lynch syndrome, the hamartomatous p...

Familial adenomatous polyposis has been linked to germline mutations in the APC tumor suppressor gene. However, a number of patients with familial adenomatous polyposis (with either classical or attenuated phenotype) have no APC mutation. Recently, germline mutations in the Wnt pathway component gene AXIN2 have been associated with tooth agenesis-colorectal cancer syndrome. Moreover, biallelic ...

BACKGROUND & AIMS An attenuated form of familial adenomatous polyposis has been described, but the phenotype remains poorly understood. METHODS We performed genetic testing on 810 individuals from 2 attenuated familial adenomatous polyposis kindreds harboring an identical germline adenomatous polyposis coli gene mutation. Colonoscopy was performed on mutation-positive persons. RESULTS The d...

Clear-cut inherited Mendelian traits, such as familial adenomatous polyposis or hereditary nonpolyposis colorectal cancer, account for <4% of colorectal cancers. Another 20% of all colorectal cancers are thought to occur in individuals with a significant inherited multifactorial susceptibility to colorectal cancer that is not obviously familial. Incompletely penetrant, comparatively rare missen...

Juvenile polyposis syndrome is a rare autosomal dominant syndrome characterized by multiple distinct juvenile polyps in the gastrointestinal tract and an increased risk of colorectal cancer. The cumulative life-time risk of colorectal cancer is 39% and the relative risk is 34. Juvenile polyps have a distinctive histology characterized by an abundance of edematous lamina propria with inflammator...

Attenuated familial polyposis (AFAP) is a subset of familial adenomatous polyposis (FAP) that has a relatively benign disease course. AFAP is characterized by no more than 100 colorectal polyps and has a tendency toward rectal sparing, a 20–25-year delay in the onset of adenomatosis and bowel symptoms, a 10–15-year delay in the development of colorectal cancer, and death caused by colorectal ca...