Familial adenomatous polyposis, is an inherited colorectal cancer syndrome that can be passed from one generation to the next by a specific error or mutation in the genetic code of the APC gene. Virtually everyone that carries a mutation of the APC gene will eventually develop cancer in the lower part of the digestive system, including the large intestine (colon) and rectum. This disease can become active in childhood with the development of adenomatous polyps causing bleeding with bowel movements, diarrhea, or abdominal pain usually in the mid teenage years however, exceptions are the rule. Colon adenomas can progress to cancer without causing apparent symptoms and can be silent killers. The average age for colon cancer is about 39 years. However, colon cancer can develop during the teen years and can develop in the absence of digestive problems. Some people have a variant of the disorder, called attenuated familial adenomatous polyposis, in which adenomas are fewer in number and develop later in life, yet these patients also have significant risk of colorectal cancer but at a later average age of about 55 years. Surgery can reduce the colon cancer risk and is currently the best therapy for this disease. Patients with FAP are at risk for cancers and tumor growths elsewhere in the digestive tract and body. Close follow up with regular checkups is an important way to avoid further complications from this disease.
Hereditary nonpolyposis colorectal cancer, often called HNPCC or Lynch Syndrome, is an inherited cancer syndrome that affects the digestive tract, reproductive tract and other major organs. People with Lynch Syndrome have an increased risk of cancers of the stomach, small intestine, liver, gallbladder ducts, upper urinary tract, brain, skin, and prostate. Women with this disorder also have a greatly increased risk of endometrial and ovarian cancer. Colon cancers develop from adenomatous polyps that occur at an earlier age than do colon polyps in the general population. Although previously thought of as a disease presenting in adulthood, teenagers from Lynch syndrome families can develop active symptoms, including colon cancers. Lynch Syndrome adenomas do not develop in large numbers but progress to cancer more quickly than the occasional adenomas found in otherwise healthy people. Lynch Syndrome is caused by a genetic mistake, or mutation, in one of four blueprint genes that make DNA repair proteins. When the DNA repair system does not work properly, harmful DNA mistakes are passed on as the cells multiply leading to disorganized growth and the development of cancer. Although mutations in these genes predispose individuals to cancer, not all people who carry these mutations develop cancerous tumors. Careful follow-up, including examination of the large intestine or colon (colonoscopy), have been shown to reduce the risk of this disease.
Juvenile polyposis syndrome is an inherited condition that is characterized by the development of hamartomatous polyps throughout the digestive tract. The term juvenile polyposis refers to the type of polyp (juvenile polyp) that is found on pathology examination rather than the age at which people are diagnosed with JPS. The number of polyps a person has during his or her lifetime can range from none to hundreds and polyp development can begin at any time in life from early infancy to the geriatric years. Most juvenile polyps are benign (noncancerous), but on occasion these polyps can become cancerous with JPS families having an increased risk of colorectal, stomach, small intestine, or pancreatic cancer. Genetic mistakes in two genes (BMPR1A and SMAD4) have been linked to roughly half of the families with this syndrome meaning other causative genes remain to be identified. This syndrome is known for its unpredictability. Although mutations in the JPS genes predispose individuals to polyp development and colon cancer, not all people who carry these mutations will develop colon cancer or even polyps. For these reasons, gene testing is the only reliable way to know who does and does not have this disease in JPS families with a known gene mutation. Careful follow-up, including upper and lower endoscopy (colonoscopy), can remove polyps for examination and help to reduce the risk of cancer from this disease.
Peutz-Jeghers syndrome is an inherited disorder with a 50% chance of being passed from one generation to the next. Two findings make up this disease: intestinal hamartomatous polyps and blue/black freckling or macules that can be seen on the lips, mouth, nostrils, hands, feet and genitalia. This syndrome has a significant risk of digestive and other cancers that is 15 times greater than that of the general population. The pigmented macules are usually not present at birth but become noticeable within the first 5 years of life. In some individuals, the freckles fad with age, however the disorder can be present in the absence of skin pigmentation. The gastrointestinal polyps found in Peutz-Jeghers Syndrome are typical hamartomas which can be large and bulky causing bleeding, pain, and blockage of the intestinal tract from “telescoping” of the bowel over a polyp resulting in intussusception of the small intestine. The majority of children and adolescents with PJS present with crampy pain, vomiting, and bowel obstruction resulting in emergency surgery to correct the intussusception. Newer management techniques are now designed to identify and remove the small intestinal polyps prior to the occurrence of symptoms thereby hopefully avoiding emergency surgery.
This disease is caused by a mistake/mutation in the STK11 or LKB1 gene. Using newer techniques, it is now possible to identify the mistake in over 90% of individuals that have polyps and lip freckles. Long term follow up and surveillance can reduce the cancer risk of this disease.
Additional information on Peutz Jeghers Syndrome can be found at:
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