Leading article: Ten years on, the benefits of decoding the human genome still lie ahead

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The Independent Online

It is hard now to rekindle the universal sense of excitement generated by the decoding of the human genome.

The announcement 10 years ago today merited a White House reception for the two rival scientific pioneers and a transatlantic video link with Downing Street. Mapping the genome constituted a landmark, not just in its own right as a scientific achievement, but for the medical revolution it promised.

The hopes were sky high: for an end to genetic diseases; for the treatment of inherited conditions before birth, and for medicines tailored to an individual's genetic make-up. Genetics, as a branch of science, was now thoroughly rehabilitated, and funds were shovelled towards it in anticipation of huge commercial rewards.

A decade on, it would be fair to say that progress has been far slower than the optimistic forecasts of those days. In many respects, it has been disappointing. Translating scientific discovery into clinical application is taking longer than expected. The ambition was that every individual would be able to know their genetic destiny and so be equipped to defy it. This has not – yet – come to pass. Humans are still a long way from knowing, and controlling, their fate.

This is not to say that there have been no advances, but they have been more at the level of understanding the genetic make-up of humans and the nature of medical disorders than in the development of cures. And there have been surprises. Among the greatest is the relatively small number of genes that make up a human being: a mere fifth of the expected 100,000 or so. But that relative simplicity is more than outweighed by the complexity of each one, so that every new discovery opens up the prospect of many, many more. Mapping the genome, it is now clear, was only the beginning of the beginning. Vast amounts of information are being collected, but it has to be systematised, sifted and interpreted before it is of any practical use.

Something else that has become apparent is that only a relatively small number of diseases are caused by a single-gene disorder. Most are much more complex. Nor do advances in genetic science definitively answer the nature-nurture conundrum. The environment, it turns out, can affect genes.

But the pace of research is accelerating all the time. The volume of genetic studies in progress now has combined with other technical advances, including in computing, to reduce both the time and the money required. Finding the cystic fibrosis gene 20 years ago took scientists three years and cost $50m. A similar project now would take months and cost a few thousand dollars. Decoding a genome will soon cost less than $1,000.

That progress in decoding the finer points of the human genome has been slower than expected also has benefits. So long as many conditions remain unpreventable and incurable, there is something to be said for not knowing all there is to know about one's genetic profile. Genetic maps would call into question the principles on which health insurance is based and could risk new forms of discrimination. It may not be researchers alone who need more time, but we humans, who cannot yet bear so much reality.