Principles of Inheritance and Variation Question 170

170. Which of the following is not a hereditary disease?

[2005]

(a) Cystic fibrosis

(b) Thalassemia

(c) Haemophilia

(d) Cretinism

Show Answer

Answer : d

Hints & Solution

(d) Cretinism : In this disorder, the physical growth, mental growth and sexual growth in children is retarded. Such a dwarf and sterile child is called a cretin. It is due to hyposecretion of thyroid hormones. Cystic fibrosis : It is a common disorder of caucasian race in which thick and more salty mucus blocks the respiratory tract. The homozygous recessive condition produces the defective protein which regulates chloride transport channel. Thalassemia : Due to reduced production of $\alpha$ or $\beta$ chains of haemoglobin. It is an autosomal recessive disorder. Haemophilia : Sex linked disorder due to defective recessive gene.