It was later further studied by Henry Lynch who recognized an autosomal dominant transmission pattern with those affected having relatively early onset of cancer (mean age 44 years), greater occurrence of proximal lesions, mostly mucinous or poorly differentiated adenocarcinoma, greater number of synchronous and metachronous cancer cells, and good outcome after surgical intervention. The Amsterdam Criteria was initially used to define Lynch syndrome before the underlying genetic mechanism had been worked out. The Criteria required that the patient has three family members all first-degree relatives with colorectal cancer that involves at least two generations with at least one affected person being younger than 50 years of age when the diagnosis was made. The Amsterdam Criteria is too restrictive and was later expanded to include cancers of endometrial, ovarian, gastric, pancreatic, small intestinal, ureteral, and renal pelvic origin. The increased risk of cancer seen in patients with by the syndrome is associated with dysfunction of DNA repair mechanism. Molecular biologists have linked the syndrome to specific genes such as hMSH2, hMSH1, hMSH6, and hPMS2. Peutz–Jeghers syndrome
Peutz–Jeghers syndrome is an autosomal dominant syndrome that presents with hamartomatous polyps, which are disorganized growth of tissues of the intestinal tract, and hyperpigmentation of the interlining of the mouth, lips and fingers. The syndrome was first noted in 1896 by Hutchinson, and later separately described by Peutz, and then again in 1940 by Jeghers.
Patients may have a laterally displaced apex beat, often with heave In acute cases, the murmur and tachycardia may be only distinctive signs. Tricuspid regurgitation
Patients with tricuspid regurgitation may experience symptoms of right-sided heart failure, such as ascites, hepatomegaly, edema and jugular venous distension.Signs of tricuspid regurgitation include pulsatile liver, prominent V waves and rapid y descents in jugular venous pressure. Auscultatory findings include inspiratory third heart sound at left lower sternal border (LLSB) and a blowing holosystolic murmur at LLSB, intensifying with inspiration, and decreasing with expiration and Valsalva maneuver. Patients may have a parasternal heave along LLSB. Atrial fibrillation is usually present in patients with tricuspid regurgitation

Causes
Calcific disease
Calcification of the leaflets of the aortic valve is a common with increasing age, but the mechanism is likely to be more related to increased lipoprotein deposits and inflammation than the "wear and tear" of advance age. Aortic stenosis due to calcification of tricuspid aortic valve with age comprises >50% of the disease. Aortic stenosis due to calcification of a bicuspid aortic valve comprises about 30-40% of the disease. Hypertension, diabetes mellitus, hyperlipoproteinemia and uremia may speed up the process of valvular calcification. Dysplasia
Heart valve dysplasia is an error in the development of any of the heart valves, and a common cause of congenital heart defects in humans as well as animals; tetralogy of Fallot is a congenital heart defect with four abnormalities, one of which is stenosis of the pulmonary valve.