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: Pediatrics
[{'content': "All of the following are features of down's syndrome, EXCEPT: \nSelect and explain. \nA. Increased PAPP-A, B. Increased free beta HCG levels, C. Absent nasal bone, D. Abnormal ductus venosus flow velocity", 'role': 'user'}, {'content': "Answer: A \nExplanation: In Downs syndrome the level of AFP is low, PAAP-A is low, and B hCG is high. Characteristic features of Down's syndrome are: Upslanting palpebral fissures, epicanthal folds, midface hypoplasia, and small, dysplastic pinnae. Generalized hypotonia. Cognitive disabilities Congenital hea disease, most oftenly endocardial cushion defects or other septal defectsGastrointestinal tract anomalies including esophageal and duodenal atresias The affected newborn may have prolonged physiologic jaundice, polycythemia, and a transient leukemoid reaction. Leukemia is 12-20 times more common in Down syndrome patients. Ref: CURRENT Diagnosis & Treatment: Pediatrics, 21e chapter 37. Fundamentals of Diagnostic Radiology edited by William E. Brant, page 927", 'role': 'assistant'}]