I: | Haemophilia is a sex-linked recessive disease. |
II: | Down’s syndrome is due to aneuploidy. |
III: | Phenylketonuria is an autosomal recessive gene disorder. |
IV: | Sickle cell anaemia is an X-linked recessive gene disorder |
Which of the following most appropriately describes haemophilia?
1. X-linked recessive gene disorder
2. Chromosomal disorder
3. Dominant gene disorder
4. Recessive gene disorder