The life expectancy of children born with Down's syndrome has doubled in a generation, due largely to a change in the way doctors think about them.

The life expectancy of children born with Down's syndrome has doubled in a generation, due largely to a change in the way doctors think about them.

It is one of the most dramatic improvements in health in the modern age, but it has been achieved without curing disease. There is no miracle drug or newly discovered treatment – just an altered attitude that is saving lives.

Where once children born with Down's were regarded as not worth treating, now they are more likely to be given the care that is standard among their peers. Progress in ending discrimination against people with learning disabilities is helping them to grow old.

From an average age at death of 25 in 1982, people with Down's syndrome were living to an average of 49 by 1997, US researchers report today. Although 49 is still young, the UK Down's Syndrome Association says a child born today with it has a better chance than ever of surviving beyond 60.

The extraordinary improvement in survival is testimony to the fact that advances in medical care, while justly celebrated, are worth nothing to those who cannot get access to them. Too often, people with Down's syndrome and other learning disabilities have been pushed to the back of the queue.

Down's syndrome occurs in one in 800 births and is caused by the presence of an extra copy of chromosome 21. Children are occasionally born with an extra copy of one of the other chromosomes but they never survive more than a few days. Children born with Down's, however, are mostly healthy, conspicuously happy and should look forward to many years of life. Their problem is that they are not considered "normal".

They have a characteristic appearance – short stature, plump bodies, narrow eyes, happy faces – which is immediately familiar, and they are intellectually impaired. Although they are living longer than they did, they age rapidly, with a high risk of dementia in middle age.

The US researchers, led by Quanhe Yang and colleagues of the Centres for Disease Control and Prevention in Atlanta, studied 17,800 people with Down's syndrome who died during the 15-year period from the early 1980s to the late 1990s. Writing in The Lancet, they offer three reasons why they have gained an extra 24 years of life.

"Factors that could have contributed to this improvement in survival include: de-institutionalisation and initial placement of affected infants with their families; better treatments for frequent causes of death; and changes in medical practice, including provision of cardiac surgery for children with Down's syndrome in circumstances in which it would not have been offered previously."

Carol Boys, chief executive of the UK Down's Syndrome Association, said the same improvement in survival had been seen in Britain. An estimated 40 per cent of Down's syndrome babies are born with a heart defect which, in the past, frequently went undetected. Many such defects require corrective surgery within the first year, and without it the child will die young.

"People with Down's are being screened more routinely for heart problems today. It is a cultural shift. Two decades ago, parents were told their child was not worth treating," she said.

However, there was still a long way to go before Down's syndrome people enjoyed the same level of care as everyone else, Ms Boys said. A survey by the association in 1998 found that one in four parents with affected children said they were dissatisfied with the medical care they had received.

Ms Boys said: "Some professionals were still using the word 'mongol' to refer to Down's babies, and parents reported being denied heart surgery. We found the major problem was attitudinal. Assumptions were still being made about the worth of Down's people's lives. Most paediatric cardiologists would quietly admit to you that people with Down's were not at the front of the queue for heart surgery. Discrimination extended to ridiculous things like glue ear. The attitude was 'Oh, he's got Down's, you will just have to put up with it'."

Two years ago, allegations surfaced at the Brompton hospital in London that children with Down's syndrome were being denied heart surgery. The claims by parents led to an inquiry which found that although there was no evidence of discrimination, children with Down's were "less favoured in accessing treatment because surgeons were more likely to recommend 'medical management' ", meaning their heart conditions were controlled with drugs rather than cured with surgery.

The inquiry report, published in April 2001, revealed a culture of paternalism among doctors with outdated medical practices and concluded: "As a result, the treatment offered was construed by parents as discriminatory."

Advances in heart surgery have contributed to the improved outlook for Down's children – when they have been able to get the operations. Surgery to correct the heart defects common in Down's, such as Fallot's tetralogy – a complex kind of hole in the heart – has been developed only since the late 1970s, and the difficulties with it were highlighted by the Bristol heart surgery scandal, which involved many babies with Down's syndrome.

Thirty years ago, people with Down's syndrome lived completely different lives. Often they went straight into institutions and rarely attended school. There was no legal requirement for them to go to school because they were regarded as ineducable. The law has since changed and more children are now being educated in mainstream schools. When they grow older they experience the same desires, frustrations and emotions as other teenagers, and increasingly resist the stereotypical view of them as happy, eternal children.

As adults, they are no longer confined in institutions but are more likely to live in small group homes with support so they can lead near-normal lives in the community. As their care has improved, so their choices and their prospects have grown. It is one of the great medical success stories. "There has been a massive change in what Down's children can expect in terms of what they make of their lives," said Ms Boys.