Question

An autosomal recessive disease caused by point mutation is:

• A. Sickle cell anaemia
• B. Graves' disease
• C. Haemophilia
• D. Addison's disease

Answer 1

Answer:

A. Sickle cell anaemia

• Sickle cell anaemia results from a specific point mutation (substitution of adenine for thymine in the beta-globin gene on chromosome 11), causing glutamic acid to be replaced by valine at position 6 of the beta-globin chain. This is inherited in an autosomal recessive pattern, where both alleles must carry the mutation for the disease to manifest.