Is There a Difference Between the NHS and Private Companies?

The actor Chris Hemsworth took a genetic test that flagged him up as being at a higher risk of developing outside of his disease. After finding this out, he's taken a break from acting to think about his health and his future. There are different technical ways of measuring the bits of DNA you need. Sometimes these tests are done on the NHS, sometimes they're done by private companies. They're all trying to measure either specific things or in some cases many things in our DNA.