Question

Sickle cell disease results from a nonsynonymous point mutation of the HBB gene, producing an altered beta chain of hemoglobin. Beta thalassemia is caused by a mutation to the same gene, but instead of an altered beta chain, the final protein is absent or incomplete. Which of these mutations is the most probable cause of beta thalassemia in a patient without a family history of the disease?
a. A synonymous mutation in an exon
b. A nonsynonymous point mutation resulting in a premature stop codon
c. An inversion, in which several codons have their sequence reversed
d. Several successive nonsynonymous point mutations changing many codons that code for glutamic acid to valine
e. A duplication of the HBB gene, creating too much protein product
a. A synonymous mutation in an exon

Answer 1

The mutations that is the most probable cause of beta thalassemia in a patient without a family history of the disease is A nonsynonymous point mutation resulting in a premature stop codon

Explanation:

The disorders that are related with blood are called Beta thalassemias. When the synthesis of the beta chains that are present in the hemoglobin blood does not happen this will be caused.  The result of this will be anemia with high severity.

The existence of mutations in the gene HBB on 11th chromosome is the main reason for the Beta thalassemias. It is the mutation's characteristics that determines the disease to be either severe or not. The blocking of HBB results in the decrease of the synthesis of beta chains.