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': 'Trident hand is seen in _______ \nSelect and explain. \nA. Achondroplasia, B. Mucopolysaccharidosis, C. Osteopetrosis, D. Cleidocranial dysostosis', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Trident hand is seen in achondroplsia; sho with stubby fingers, with a seperation between the middle and ring fingers. Achondroplasia: Autosomal-dominant chondroplasia; most common condition chracterized by dispropoionate sho stature. Caused by mutations in the gene coding for fibroblast growth factor receptor type 3 (FGFR3) Clinical features: Sho stature, extreme joint laxity, bowing of legs, macrocephaly, frontal bossing, midfacial hypoplasia, small chest, redundant skin folds, recurrent infections, cor pulmonale, and restrictive pulmonary disease. Radiological features in achondroplasia Champagne glass pelvic inlet Trident hand Shoening of tubular bones with metaphyseal flaring Chevron deformity Ref: Nelson textbook of pediatrics 21st edition Pgno: 3726', 'role': 'assistant'}]