<prompt> Thalassemia occurs due to which mutations a Missenseb Splicingc Transitiond Frameshifte Truncationcdbdac  <response>: Thalassemia syndrome Adult hemoglobin is a tetramer, composed of two a globin chains and two β globin chains.Thalassemia is an inherited autosomal recessive disorder.In Thalassemia, the gentic defect results in reduced synthesis of one of the globin chains of hemoglobin.β- Thalassemia is caused by deficient synthesis of β-chain with normal α-chain synthesis.α- thalassemia is caused by deficient synthesis of α-chain with normal β-chain synthesis.Molecular defect in pathogenesis of thalassemia.A β-thalassemiaMost common type of genetic abnormality in -thalassemia is point mutation, i.e. nonsense.Some may also. occur due to deletion or insertion i.e. framshift mutations.Defect may occur at different steps of β-chain synthesis -i Splicing mutationsMutations leading to aberrant splicing are the most common cause of β-thalassemia. 10 Chain terminator mutationsThis cause premature termination of mRNA translation.iii Promoter region mutationsThis results in transcription defectB α-thalassemiaThe most common cause of reduced α-chain synthesis is the deletion of α-globin genes.Rarely nonsense mutation may also cause α-thalassemia. 