This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Abnormalities of Development, Subject name: Pediatrics
[{'content': 'What is the diagnosis in this child with intellectual disability? \nSelect and explain. \nA. Rubinstein Taybi syndrome, B. Seckel syndrome, C. Fragile X syndrome, D. Rett syndrome', 'role': 'user'}, {'content': "Answer: C \nExplanation: Elongated face with large protruding ears, in a male with intellectual disability suggests a diagnosis of Fragile X syndrome. Fragile X syndrome or Main-Bell syndrome: Due to Gene Mutation in the FMR1 gene on chromosome - X CGG trinucleotide repeats Second most common genetic cause of intellectual disability after Down's syndrome Males are more severely affected by than females. CLINICAL FEATURES: Long face Hyperextensible joints High Arched Palate Mitral valve prolapse Large Mandible Large Ears Large testis/ macroorchidism ( In post- pubeal males) OTHER OPTIONS : Seckel syndrome- elongated bird facies, beak like nose, microcephaly Rett syndrome- acquired microcephaly Rubinstein Taybi syndrome- microcephaly, micrognathia, high arched palate, low set ears, angulated thumb.", 'role': 'assistant'}]