Question

Haemophilia is caused by

• A. Dominant sex-linked gene
• B. Recessive sex-linked gene
• C. Recessive autosomal gene
• D. Dominant autosomal gene

Answer 1

Answer: (B)

Recessive sex-linked gene

The hemophilia gene is passed down from parent to a child. Haemophilia is a bleeding disorder, usually inherited with an X-linked recessive inheritance pattern, which results from the deficiency of a coagulation factor. The genes for hemophilia A and B are on the X chromosome. For this reason, hemophilia is called an X-linked (or sex-linked) disorder.

So, the correct answer is 'Recessive sex-linked gene'.