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': 'Thalassemia occurs due to which mutations –a)  Missenseb)  Splicingc)  Transitiond)  Frame–shifte)  Truncation \nSelect and explain. \nA. c, B. d, C. bd, D. ac', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Thalassemia syndrome\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\xa0\n\nAdult hemoglobin is a tetramer, composed of two a globin chains and two β globin chains.\nThalassemia is an inherited autosomal recessive disorder.\nIn Thalassemia, the gentic defect results in reduced synthesis of one of the globin chains of hemoglobin.\nβ- Thalassemia is caused by deficient synthesis of β-chain with normal α-chain synthesis.\nα- thalassemia is caused by deficient synthesis of α-chain with normal (β-chain synthesis.\nMolecular defect in pathogenesis of thalassemia.\n\nA) β-thalassemia\n\nMost common type of genetic abnormality in (-thalassemia is point mutation, i.e. nonsense.\nSome may also. occur due to deletion or insertion i.e. framshift mutations.\nDefect may occur at different steps of β-chain synthesis -\n\ni)\xa0\xa0\xa0 Splicing mutations\n\nMutations leading to aberrant splicing are the most common cause of β-thalassemia. 10 Chain terminator mutations\nThis cause premature termination of mRNA translation.\niii) Promoter region mutations\nThis results in transcription defect\n\nB) α-thalassemia\n\nThe most common cause of reduced α-chain synthesis is the deletion of α-globin genes.\nRarely nonsense mutation may also cause α-thalassemia.', 'role': 'assistant'}]