Question

A point mutation is?

• A. Sickle cell anaemia
• B. Thalassemia
• C. Night blindness
• D. Down's syndrome

Answer 1

The correct option is A Sickle cell anaemia

The mutation causing sickle cell anemia is a single nucleotide substitution (A to T) in the codon for amino acid 6. The change converts a glutamic acid codon (GAG) to a valine codon (GTG). Sickle cell anemia is the result of a point mutation, a change in just one nucleotide in the gene for hemoglobin. This mutation causes the hemoglobin in red blood cells to distort to a sickle shape when deoxygenated. The sickle-shaped blood cells clog in the capillaries, cutting off circulation.

So, the correct answer is 'Sickle cell anaemia'.