Sickle cell anaemia is a human condition that affects haemoglobin, reducing the blood's ability to carry oxygen - Scottish Highers Biology - Question 6 - 2019

The type of mutation that leads to sickle cell anaemia is a substitution mutation. This specific mutation occurs when one base in the DNA sequence is replaced with another. In this case, an adenine (A) is changed to thymine (T), resulting in the alteration of a single amino acid in the hemoglobin protein. This change in amino acid leads to the characteristic sickling of red blood cells associated with the condition.