Defect in Snurps causes-
Sickle cell anemia
Thalassemia
Marfan syndrome
EDS
Ans. is 'b' i.e., Thalassemiao Defective splicing (defect in snurps) is the most common mutation causing thalassemia,o Molecular defect in pathogens is of thalassemia:-b-Thalassemiao Most common type of genetic abnormality in b-thalassemia is point mutation i.e., nonsense.o Some may also occur due to deletion or insertion i.e., frame shift mutations,o Defect may occur at different steps of b-chain synthesis:i) Splicing mutationso Mutations leading to aberrant splicing are the most common cause of b-thalassemia.ii) Chain terminator mutationso This cause premature termination of mRNA translation.iii) Promoter region mutationso This results in transcription defect.a-Thalassemiao The most common cause of reduced a-chain synthesis is deletion of a-globin genes,o Rarely nonsense mutation may also cause a-thalassemia.
Molecular Genetics