Familial Adenomatous Polyposis Essay

Throughout the years, geneticists have made ground breaking discoveries, in regards to thousands of inherited diseases. They have identified numerous mutations within the human genome that have given rise to treatments and cures for multiple genetic diseases, one of which is Familial Adenomatous Polyposis, also known as FAP. According to Half, Brocovich, and Rozen (2009)1, Familial Adenomatous Polyposis is characterized by the development of many tens of thousands adenomas in the rectum and colon during the second decade of life. Familial Adenomatous Polyposis is inherited as an autosomal dominant disease, which is the reason why there is a relatively equal occurrence rate in males and females. FAP results from a germline mutation in the adenomatous
According to Half, Brocovich, and Rozen (2009), more than 300 different types of mutations are recognized today as the cause of FAP. The mutations range from insertions, deletions, nonsense, and even repeats, which ultimately can result in a nonfunctional protein. The APC gene produces a protein known as the APC protein that is involved in regulating cell adhesion, signal transductions, and transcription activation. Park and Vogelstein (2003) stated that, “the localization of the APC protein is in the basolateral membrane of the colonic epithelial cells…” When mutations occur within this specific gene, it causes excessive proliferation of the colonic epithelial cells, which result in the formation of polyps and eventually tumors throughout the colon. There are certain medications that are provided for patients with this genetic disease, but they are simply given to treat and reduce the number and size of polyps. The prognosis for an individual with Familial Adenomatous Polyposis is that they will eventually have to undergo surgery to prevent colorectal cancer and malignant tumors from
According to Half, Rozen, and Brocovich (2009), the APC gene spans a region of 108,353 base pairs and is located on the long arm of chromosome five. They also stated that the mRNA is 10,719 base pairs long and encodes for a protein that has 2,843 amino acids. (Half, et al 2009). Half, Rozen, and Brocovich (2009) reported that mutational analysis of the APC gene indicated that the majority of germline mutations found in patients with FAP are nonsense mutations, leading to the formation of a truncated protein. A nonsense mutation is when a codon is terminated prematurely, resulting in a shortened and in this case a nonfunctional protein. The APC protein contains a mutation cluster region, also known as the MCR, where 60% of the APC mutations occur. This region is located between codons 1284 and 1580. (Half, et. al, 2009). As mentioned before, the APC gene produces a protein called the APC protein. The APC protein binds to the Beta-Catenin to prevent it from interacting with proliferation genes. However, if Beta-Catenin is bound to the mutated or nonfunctional APC protein then it will be able to accumulate and allow excessive proliferation of the colonic epithelial cells, which results in the formation of polyps and eventually tumors in the colon and