Lynch syndrome was first described by Dr. Henry T. Lynch, an American physician, in 1966.<unk>  may be classified into 2 types: Lynch syndrome I (familial colon<unk>  and Lynch syndrome II<unk>  associated with other<unk> s). Other variants such as Muir-Torre syndrome and Turcot syndrome are considered subtypes of<unk> .<unk>  is an autosomal dominant genetic disease characterized by an early onset of colon<unk> , endometrial<unk> , and other malignant tumors. Development of<unk>  is the result of multiple genetic mutations. The genes involved in the pathogenesis of<unk>  include: MSH-2, MLH-1, MSH-6, PMS-2 , PMS-1, TGF-BR2, and MLH-3. This syndrome occurs most commonly in the proximal colon (60% to 80%). Endometrial<unk>  is the most common sentinel<unk>  among female patients with<unk> .<unk>  is caused by germline mutations in one of the four MMR genes (MLH1, MSH2, MSH6, or PMS2), that results in defective repair of DNA sequence. Deletions in the EPCAM gene also cause<unk> .<unk>  must be differentiated from other diseases that cause familial<unk><unk> , such as: juvenile polyposis, familial adenomatous polyposis, Cowden syndrome, and MYH-associated polyposis. Incidence of<unk>  is not well known but it is estimated that 0.5 to 13% of the cases of<unk><unk>  are due to<unk> . The prevalence of<unk>  is approximately 2 - 7% of all the diagnosed cases of<unk><unk> .<unk>  commonly affects young adult population. The median age of diagnosis is between 40 to 45 years.<unk>  affects males and females equally.<unk>  usually affects individuals of the white race more commonly. Ethnically-diverse individuals are less likely to develop MMR mutations related with<unk> . The most potent risk factor in the development of<unk>  is gene mutations caused by defective DNA mismatch repair. According to the Bethesda guidelines and Amsterdam criteria, screening for<unk>  by genetic testing is recommended among patients with family history or/and a confirmed diagnosis of<unk><unk>  under age 50 years. If left untreated,<unk>  progression occurs rapidly and is then followed by sentinel organ<unk>  or metastasis.<unk>  is an aggressive syndrome characterized by early onset of<unk> . Affected organs include endometrium (second most common after colon), ovary, stomach, small intestine, hepatobiliary tract, upper urinary tract, brain, and skin. Complications of<unk>  are usually related to the surgery. The 5-year relative survival of patients with<unk>  is approximately 79.3%. A feature associated with worse prognosis is late stage diagnosis. The hallmark of<unk>  is a first-degree relative with known MMR/EPCAM gene mutation. A positive family history of<unk><unk>  and meeting Amsterdam I or II criteria or revised Bethesda guidelines is highly suggestive of<unk> . Some symptoms that are associated with<unk><unk>  are change in bowel habits, hematochezia, and rectal pain. Patients with<unk>  usually appear healthy. Physical examination of patients with<unk>  may show the presence of the fordyce granules. Laboratory findings consistent with the diagnosis of<unk>  may include positive germline testing for<unk>  genes (MLH1, MSH2, MSH6, and PMS2), positive EPCAM gene testing, and elevated serum concentration of CEA and CA-125. There are no ECG findings associated with<unk> . There are no x-ray findings associated with<unk> . There are no echocardiography findings associated with<unk> . There are no ultrasound findings associated with<unk> . However, an ultrasound may be helpful as a screening tool for the diagnosis of endometrial<unk>  which is commonly found in women with this syndrome. CT scan is not routinely used for the diagnosis of<unk> . However, in some cases, CT scan can be useful in the detection of extracolonic lesions and also right-sided colon lesions (especially in the cecum) which are not easily seen with colonoscopy. Magnetic resonance colonography (MRC) is not routinely used for the diagnosis of<unk> . Although it is associated with less discomfort as compared to colonoscopy, it has poor sensitivity in detecting small polyps, limiting its utility in adenoma screening at this time. There are no associated additional imaging findings for the diagnosis of<unk> . According to the American College of Gastroenterology, patients with<unk>  should undergo colonoscopy every 2 years beginning at age 20 - 25 years, until the age of 40, followed by an annual colonoscopy. Diagnostic and screening endoscopy is recommended in the case of<unk> . There is no medical treatment for<unk> . However,<unk>  patients should consider diet optimization and pharmacological prevention. Surgery is the mainstay of treatment for<unk> . Surgical resection is recommended for patients with<unk>  because of the high rate of metachronous<unk><unk> . Subtotal colectomy with ileo-rectal anastomosis and postsurgical endoscopic rectal surveillance are advised when<unk><unk>  develops in the setting of<unk> . There is no established method for the primary prevention of<unk> .There are no established measures for the primary prevention of<unk> . Secondary prevention strategies following<unk>  include genetic testing, colonoscopy, urine cytology, pelvic exam, and endometrial biopsy.
Hereditary nonpolyposis colorectal cancer
Familial adenomatous polyposis
Peutz-Jeghers syndrome
Hereditary and familial colorectal cancer
Fabry's disease
Pickering syndrome
Celiac disease
Familial adenomatous polyposis pathophysiology