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: Microbiology
[{'content': 'Defect seen in Di George syndrome: September 2009 \nSelect and explain. \nA. Humoral immunity, B. Cell mediated immunity, C. Thymic hyperplasia, D. Autoimmune hemolytic anaemia', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Ans. B: Cell mediated immunity DiGeorge anomaly (DGA) is a congenital immunodeficiency characterized by abnormal facies; congenital hea defects; hypoparathyroidism with hypocalcemia; cognitive, behavioral, and psychiatric problems; and increased susceptibility to infections. Pathological hallmarks include conotruncal abnormalities and absence or hypoplasia of thymus and parathyroid glands. Thymic hypoplasia or aplasia leading to defective T-cell function (cell mediated immunity) is the hallmark of DiGeorge anomaly Microdeletion of chromosome 22 accounts for more than 90% of cases of DiGeorge anomaly. Deletions of chromosome 22q11.2 are found in the vast majority of patients with DiGeorge anomaly', 'role': 'assistant'}]