The flushing also results from secretion of kallikrein, the enzyme that catalyzes the conversion of kininogen to lysyl-bradykinin. The latter is further converted to bradykinin, one of the most powerful vasodilators known. Other components of the carcinoid syndrome are diarrhea (probably caused by the increased serotonin, which greatly increases peristalsis, leaving less time for fluid absorption), a pellagra-like syndrome (probably caused by diversion of large amounts of tryptophan from synthesis of the vitamin B3 niacin, which is needed for NAD production, to the synthesis of serotonin and other 5-hydroxyindoles), fibrotic lesions of the endocardium, particularly on the right side of the heart resulting in insufficiency of the tricuspid valve and, less frequently, the pulmonary valve and, uncommonly, bronchoconstriction.The pathogenesis of the cardiac lesions and the bronchoconstriction is unknown, but the former probably involves activation of serotonin 5-HT2B receptors by serotonin. When the primary tumor is in the gastrointestinal tract, as it is in the great majority of cases, the serotonin and kallikrein are inactivated in the liver; manifestations of carcinoid syndrome do not occur until there are metastases to the liver or when the cancer is accompanied by liver failure (cirrhosis). Carcinoid tumors arising in the bronchi may be associated with manifestations of carcinoid syndrome without liver metastases because their biologically active products reach the systemic circulation before passing through the liver and being metabolized.In most patients, there is an increased urinary excretion of 5-HIAA (5-hydroxyindoleacetic acid), a degradation product of serotonin.The biology of these tumors differs from many other tumor types.
Yao syndrome (YAOS) (formerly called NOD2-associated autoinflammatory disease) is an autoinflammatory syndrome involving episodes of fever and abnormal inflammation affecting many parts of the body, particularly the skin, joints, and gastrointestinal system. Signs and symptoms
Arthralgia (Arthritis)
Fever
Diarrhea
Abdominal Pain
Keratoconjunctivitis Sicca (Dry eyes)
Pleurisy
Idiopathic Pericarditis
Xerostomia (Dry mouth)
Erythematous Plaques
Dermatitis

Diagnostic criteria
Yao syndrome is diagnosed if 2 major criteria, at least one minor criterion, the molecular criterion, and exclusion criteria are fulfilled. Treatment
A study to determine the effectiveness of Novartis pharmaceutical drug Canakinumab was conducted. In this study, canakinumab was effective in patients with YAOS, and thus clinical trial of canakinumab may be warranted as a therapeutic option for this disease. Inheritance
Yao Syndrome inheritance is classified as Multifactorial Inheritance. References
External links

MedGen-Yao Syndrome
Genetics Home Reference-Yao Syndrome