In: Facts
In the Cell
What is a mutation?
A mutation is a change that occurs in our DNA sequence, either due to mistakes when the DNA is copied or as the result of environmental factors such as UV light and cigarette smoke.
- Over a lifetime our DNA can undergo changes or ‘mutations’ in the sequence of bases, A, C, G and T.
- This results in changes in the proteins that are made. This can be a bad or a good thing.
- Mutations can occur during DNA replication if errors are made and not corrected in time.
- Mutations can also occur as the result of exposure to environmental factors such as smoking, sunlight and radiation.
- Often cells can recognise any potentially mutation-causing damage and repair it before it becomes a fixed mutation.
- Mutations contribute to genetic variation within species.
- Mutations can also be inherited, particularly if they have a positive effect.
- For example, the disorder sickle cell anaemia is caused by a mutation in the gene that instructs the building of a protein called haemoglobin. This causes the red blood cells to become an abnormal, rigid, sickle shape. However, in African populations, having this mutation also protects against malaria.
- However, mutation can also disrupt normal gene activity and cause diseases, like cancer
- Cancer is the most common human genetic disease; it is caused by mutations occurring in a number of growth-controlling genes. Sometimes faulty, cancer-causing genes can exist from birth, increasing a person’s chance of getting cancer.
An illustration to show an example of a DNA mutation.
Image credit: Genome Research Limited
This page was last updated on 2016-01-25