Thalassemia mutations | PGI entrance Preparations

Thalassemia occurs due to which mutations A. Missense 
B. Splicing 
C. Transition 
D. Frame-shift 
E. Truncation

Ans. B. Splicing; D) Frame-shift : 

              Important causes of thalassemia are 

• β—thalasssemia : A wide variety of mutations in β—globin gene including deletion, nonsense and Frameshift mutation, and others affecting every aspects of its structure (e.g. splicing sites, promotor mutans) 

•α-thalassemias . Mutations in α-globin gene mainly unequal crossing over and large

DELETIONS and less commonly nonsense and Frame shift mutations.

• Mutations causing β-thalassernia can affect at any step in the pathway of globin geneexpression transcription, processing of m-RNA precursors, translation and post translational meta

bolism of β—gIobin polypeptide chain

• The most common forms arise from mutations that derange SPLICING of mRNA precursor or

permenantly terminate translation of mRNA.