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.
