Steve Connor: Revolution could save huge amounts of time, money – and lives

When the first draft of the human genome was announced in 2000, President Bill Clinton said in a live satellite link between the White House and Downing Street that the breakthrough represents a triumph of science and reason. "Today, we are learning the language in which God created life," he said.

Many scientists may have winced over his use of the G-word but few would have argued about the President's sentiment of this being a monumental moment in human history. For the first time, we were able to begin to read our full set of genetic instructions – the digital recipe for a man and a woman locked in our DNA.

But it didn't come cheap. Ten years ago, the cost of deciphering the entire 3 billion letters of a person's DNA ran into hundreds of millions of pounds. Now, it is down to about £31,000 and falling fast. Soon, it will be done for a couple of hundred pounds, and perhaps one day for the price of a haircut. The importance of this development in genetic deflation cannot be underestimated. If the genome project were ever to bear fruit for ordinary patients and the NHS, the cost of deciphering someone's DNA had to fall drastically.

The aim eventually is to bring about some kind of "personalised medicine", where a therapy or drug treatment is tailored to a patient's particular genetic makeup. It is believed on good evidence, for instance, that some people do not respond to certain drugs because of variations in their DNA. If these mutations could be identified before taking a drug, and not after side effects begin to show, then much time, money and suffering could be saved.

Already, there are drugs available that work best on people with a specific genetic makeup. The Herceptin anti-cancer drug, for instance, targets the breast tumour protein HER-2, for which about one patient in every five tests positive in DNA tests.

Another genetic test can identify certain mutations in a gene called HNF1-alpha. People with this mutation have symptoms that are often wrongly diagnosed as diabetes type-1. A correctly administered test makes sure they are given the right sort of treatment, rather than the standard insulin injections offered to diabetics.

On paper, and in practice, there seems much to be said for cheaper genome sequences. But with an NHS under financial strain, the question is whether it will ever be able to afford the cost of DNA sequencing – even if they may save money as well as lives in the long run.

But if full genetic sequences really do become dirt cheap, their benefits will quickly become apparent and personalised medicine should be available to all who need it.