The mutation in the haemoglobin gene causes _________________.
-
phenylketonuri
-
cystic fibrosis
-
sickle-cell disease
-
Tay–Sachs disease
-
haemophilia
C
Correct answer
Explanation
Sickle-cell disease is a hereditary blood disorder, characterized by red blood cells that assume an abnormal, rigid sickle shape. Sickling decreases the cells' flexibility and results in a risk of various life-threatening complications. This sickling occurs because of a mutation in the haemoglobin gene.