This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Dental
[{'content': 'All are true regarding hereditary angioedema,except ?a) Dysfunction of enzyme is most common causeb) Enzyme involved is C1 INHc) C1 inhibitor targests Hageman factord) Complement C4 & C2 decreasee) Bradykinin level decrease during attack \nSelect and explain. \nA. a, B. b, C. ce, D. ae', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Hereditary angioneurotic edema is due to deficiency of C1 inhibitor (C1 INH) or loss of function (dysfunction) of C1\xa0inhibitor. Deficiency (85%) is more common than dysfunction (15%).\nC1 inhibitor targets and inactivates :-\nC1r\xa0and C1s\xa0(these two initiate the classical complement pathway).\nFactor XII a (Hageman factor) and kallikrein (both of these participate in contact activation of blood coagulation system.\nIn C1 inhibitor deficiency, these enzymes can not be inactivated and two pathways (classical complement pathway and coagulation system) become unregulated and there is excessive production of bradykinin and C2 kinin. This leads to increased capillary permeability and angioedema.\nThere is depletion of C2 to C4 level as they are consumed in unregulated classical complement pathway.', 'role': 'assistant'}]