This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Thalassemia, Subject name: Medicine
[{'content': 'In Beta thalassemia, the most common gene mutation is? \nSelect and explain. \nA. Intron 1 inversion, B. Intron 22, C. 619 bp deletion, D. 3.7 bp deletion', 'role': 'user'}, {'content': 'Answer: A \nExplanation: The most common mutation causing a thalassemia is intron 1 inversion b thalassemia- AR, caused due to reduced synthesis of beta chain of hemoglobin. b thalassemias are the consequence of various point mutations on the globin gene clusters. Thalassemia mutations in India Mutations Frequency IVS1-5(G-C) 48% 619 bp deletion 18% IVS-1(G-T) 9% FR41/42(TCTT) 9% FR8/9 (+G) 5% Codonl5 (G-A) 5% Others 6% Total 100%', 'role': 'assistant'}]