Ques. 1NEET 2017
Thalassemia and sickle cell anemia are caused due to a problem in globin molecule synthesis. Select the correct statement.
- Both are due to a qualitative defect in globin chain synthesis
- Thalassemia is due to less synthesis of globin molecules
- Sickle cell anemia is due to a quantitative problem of globin molecules
- Both are due to a quantitative defect in globin chain synthesis
Answer
(2) Thalassemia is due to less synthesis of globin molecules
Solution
As per NCERT, thalassemia differs from sickle-cell anaemia in that the former is a quantitative problem of synthesising too few globin molecules, while the latter is a qualitative problem of synthesising an incorrectly functioning globin.
In thalassemia, a mutation/deletion reduces the rate of synthesis of α or β globin chains (less globin), whereas in sickle-cell anaemia Glu is substituted by Val at the 6th position of the β-globin chain (abnormal globin).
∴ Thalassemia is due to less synthesis of globin molecules.
Answer: (2)