Sickle cell anaemia is:

Sickle cell anaemia has not been eliminated from the African population because:

1. It is controlled by recessive genes

2. It is not a fatal disease

3. It provides immunity against malaria

4. It is controlled by dominant genes

Both sickle cell anaemia and Huntington’s chorea are:

1. bacteria-related diseases.

2. congenital disorders

3. pollutant-induced disorders

4. virus-related diseases