- Cystic Fibrosis.
Cystic fibrosis sufferers cannot digest certain fats or absorb them and it is caused by inheriting two copies of defective gene, which means that the mucous glands in the digestive, respiratory, reproductive and sweat glands do not function properly.
- Corrective Mutation
Mutations occur through the following methods:
- Chromosomal Interchange.
Here, parts of the DNA become transposed or just moved around. Again, this can become a mutation. Whole parts of the DNA become swapped or moved in this process.
- Point Mutation.
DNA nucleotides are moved around inside the DNA strand.
Due to the statistical vagaries of the whole process, the chances of an insertion mutation happening to delete the existing CF mutation would be almost infinitesimal and there would be a greater chance of winning the lottery or being struck by lightning.
The whole process of cellular division is too complex to randomly hope that a mutation would simplify the situation. In reality, it is more likely to make things worse.