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': "Increased nuchal fold thickness is a feature of – \nSelect and explain. \nA. Paul–Bunnel syndrome, B. De–pan syndrome, C. Down's syndrome, D. Cri–duchat syndrome", 'role': 'user'}, {'content': "Answer: C \nExplanation: Nuchal fold thickness is increased in Down syndrome. This feature is used in suspecting the diagnosis of Down's syndrome prenataly.\nDown's syndrome \n\nDown's syndrome is due to trisomy 21.\nDown's syndrome is the most common trisomy.\nIn this condition, extra genetic material causes a delay in the way a child develops and often leads to mental retardation.\nIn Down's syndrome the child gets on the extra chromosome, he has a total of 47 chromosomes instead of 46 chromosomes.\nThis is the extra genetic material that causes the physical and cognitive delays associated with Down's syndrome.\nThere is a well-recognized association with advanced maternal age, the risk considerably increases in women > 35 years of age.\nAdvanced paternal age has no effect.", 'role': 'assistant'}]