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: Medicine
In Beta thalassemia, the most common gene mutation is 
Select and explain. 
A. Intron 1 inversion, B. Intron 22, C. 619 bp deletion, D. 3.7 bp deletion
A: Intron 1 inversion
Answer: A: Intron 1 inversion 
Explanation: Ans. is 'a' i.e., Intron 1 inversion Thalassemias are autosomal recessive disorder The most common mutation causing 13 thalassemias is intron/inversion Also know: Synthesis of alpha chain is controlled by 2 gene clusters on - Chromosome 16 Synthesis of beta chain is controlled by 2 gene clusters on - Chromosome 11 Thalassemia mutations in India Multations Frequency IVS1-5 (G -->C) 48% 619 bp defection 18% IVS-1 (G T) 9% FR41/42(TCTT) 9% FR8/9 (+G) 5% Codonl5 (G --> A) 6% Others 100%