The NHS will set up 11 centres to unlock the secrets of DNA and usher in a new era of "genomic medicine".
Blank
The Genomics Medicine Centres - based in hospitals from Newcastle to Exeter - will focus on cancer and rare genetic diseases.
Their challenge is to sequence 100,000 genomes within three years in order to develop new tests and drugs.
The NHS said it was aiming to be the most scientifically advanced healthcare system in the world.
Target treatment
The eleven Genomics Medicines Centres will open across England in February at:
For cancer, the aim is to target treatment at the precise mutations in DNA that are causing a patient's tumour. The genomes of healthy tissue and the tumour will be compared.
Genetic code
Previous genetics research has shown how different cancers can be - for example that breast cancer is not one disease but at least 10 - each with a different cause and life expectancy and each needing a different treatment.
And the development of targeted drugs such as Herceptin - given only if a patient's breast tumour has a certain mutation - has been possible because of genetics research.
Meanwhile. patients with rare diseases will have their genomes compared with the genomes of their family members.
Thousands of genetic diseases - which are individually rare, but affect combined affect large numbers of people - could be identified by finding mistakes in the three billion pairs of letters that make up our genetic code.
The resulting knowledge could give patients an explanation for a disease that has plagued their entire life.
Case study
Fifteen thousand families with rare diseases will take part in the project.
Edward Sherley-Price has first-hand experience of just how little is known about some conditions.
His 11-year-old daughter Alysia has regular seizures.
She was diagnosed with a developmental delay before her second birthday, but the cause was unknown.
It took until 2013 for genetic testing to discover what was wrong - a rare genetic mutation in a gene known as STXBP1.
The family say getting a diagnosis has given them a renewed sense of optimism.
The 100,000 Genomes Project could help people like Alysia by identifying a specific mutation, which lead to taking part in future drug trials.
The pilots have been underway this year and 3,000 genomes will have been sequenced by January.
All the data produced in the 100,000 Genomes project will be stripped of anything that could identify the patient and then be made available to drugs companies and researchers to help them create precision drugs for future generations.
'Devastating diseases'
NHS England's medical director Prof Bruce Keogh said the impact of genomic medicine will be on the same scale as other British successes including the smallpox vaccine and IVF.
He said: "Our NHS is better equipped for the emerging science that will determine the future practice of medicine than any other Western healthcare system.
"[It] puts us in a position to unlock a series of secrets about devastating diseases, that have remained hidden for centuries, for the whole of human kind."
Life sciences minister George Freeman said: "We want to make the UK the best place in the world to design and discover 21st century medicines."
Angela Douglas, the chairwoman of the British Society of Genetic Medicine, said: "The challenge of the project will be to embed its outcomes into routine health practice.
"The genetics community looks forward to working with researchers, scientists, associated medical specialists and Genomics England to meet that challenge."
