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': 'Down Syndrome, All are seen except – \nSelect and explain. \nA. t(14 ; 21), B. Trisomy 21, C. t(11 : 14), D. t(15 :21)', 'role': 'user'}, {'content': 'Answer: C \nExplanation: In 95% of cases of Down Syndrome - trisomy of 21\nExtra chromosome is of maternal in origin\n1% have mosaic with 46 chromosomes\n4% have Robertsonian translocation.\nt(13:21)\nt (14 : 21)\nt (15 : 21)\nVery rarely long arm of chromosome 21 is triplicate (Partial trisomy)', 'role': 'assistant'}]