Question

$\alpha$-thalassemia is due to defective genes on chromosome

• A. $16$
• B. $12$
• C. $9$
• D. $11$

Answer 1

The correct option is A $16$

Thalassemia is an inherited disease of faulty synthesis of hemoglobin. Thalassemia consists of a group of disorders that may range from a barely detectable abnormality of blood, to severe or fatal anemia. Adult hemoglobin is composed of two alpha (α) and two beta (β) polypeptide chains. There are two copies of the hemoglobin alpha gene (HBA1 and HBA2), which each encode an α-chain, and both genes are located on chromosome 16. The hemoglobin beta gene (HBB) encodes the β-chain and is located on chromosome 11. In α-thalassemia, there is deficient synthesis of α-chains. The resulting excess of β-chains bind oxygen poorly, leading to a low concentration of oxygen in tissues (hypoxemia).

So, the correct answer is '16'.