Can DNA sequencing be used in personalised medicine?

When will DNA sequencing completely transform and how can it be used in personalised treatments?

DNA sequencing already has numerous uses in medicine (pregnancy tests for genetic disorders, cancer diagnosis and treatment, reaction/ resistance to different drugs).
It is safe to say that in the coming years DNA sequencing will increasingly be used in quick routine medical tests, dentistry (to prevent teeth degradation even before signs of deterioration are seen), skin treatments (skin rejuvenation, acne treatments), cancer diagnosis and prevention, birth planning, personalised diets, personalised fitness programs etc.