This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Genetic and genetic disorders, Subject name: Pediatrics
[{'content': 'Which of the following is not a feature of Pierre-Robin syndrome? \nSelect and explain. \nA. Hearing defects, B. Coloboma iris, C. Respiratory distress, D. Mandibular hypoplasia', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Coloboma iris is not a feature of Pierre-Robin syndrome. Feature of Pierre-Robin syndrome: Micrognathia accompanied by a high-arched or cleft palate Tongue normal size; the floor of the mouth is foreshoened Of the children with Pierre-Robin syndrome, 30-50% have Sticker syndrome: Prominent joints, ahritis, hypotonia, hypermobile joints, mitral valve prolapse, hearing loss, and ocular problems(myopia, glaucoma, cataracts, retinal detachment) Pierre-Robin Syndrome: Micrognathia, Retrognathia, Glossoptosis: Micrognathia: small mandible Retrognathia: retracted mandible Glossoptosis/Retroglossoptosis: tongue appears to fall into the throat (retraction of the tongue) Ref: Nelson textbook of pediatrics 21st edition Pgno: 1917', 'role': 'assistant'}]