How can you tell if there is a genetic mutation?

Question: How can you tell if there is a genetic mutation?
- Keywords:
  genetics,
  mutation
Asked by Clownfish to Gaia on 7 Mar 2016.
- Gaia Andreoletti answered on 7 Mar 2016:
  
  A few years back scientist got together and sequenced over 1,000 individuals to have a complete “draft” of the human genome. Over the years, this draft has been updated and optimized. I am able to see if there is a genetic mutations by comparing each base of the patient’s genome to the genome draft.

Question: How can you tell if there is a genetic mutation?