Screening will lead to end of Alzheimer's

Scientists predict disease will be eliminated within generations

The children of today will be the first generation who will be routinely screened and treated for Alzheimer's disease when they reach middle age, according to one of the world's leading experts in the most common degenerative brain disorder of old age.

Advances in genetics over the next five years will lead to the first major change in the way Alzheimer's patients are identified. In 50 years, these advances will eventually lead to prevention of the disease before it strikes, said Rudolph Tanzi, professor of neurology and neuroscience at Harvard Medical School.

"Put another way, the most efficient and safest way to treat Alzheimer's disease is at its deepest roots -- by nipping the disease process in the bud," Professor Tanzi told the annual meeting of the American Association for the Advancement of Science in Denver, Colorado.

"This is best accomplished by first acquiring a profound understanding of the genetic basis for the cause of the disease. Genetic findings over the years indicate that in virtually every case of Alzheimer's, inheritance and genetics plays at least some role," said Professor Tanzi, who was part of the team that found the first gene involved in triggering the disease.

Western countries face a health crisis of unprecedented proportions as a result of the growing number of people in an ageing population who will develop Alzheimer's, which leads to progressive and irreversible mental deterioration marked by a loss of memory, judgement and the ability to reason.

In addition to the trauma for both sufferers and their families, the health care costs are set to escalate as the population gets older.

"If it is not cured, the national cost of managing this dreadful disease [in the US alone] will likely consume the entire federal government budget by 2025," Professor Tanzi said.

A 10-year study of 500 families with Alzheimer's has helped to uncover the genetic basis underpinning about 30 per cent of the risk of getting the disease.

Professor Tanzi said: "This research lays the groundwork for identifying genes that will allow us to reliably predict the disease before it strikes. The ultimate goal is to custom-make drugs to address our own genetic properties. Genetic findings over the years indicate that in virtually every case of Alzheimer's, inheritance and genetics plays at least some role.

"As Alzheimer's genes have been uncovered, the biological pathways that become impaired in the disease have gradually been elucidated, paving the way for the development of effective therapies for prevention and treatment of the disease."

It is known that high cholesterol is a risk factor in Alzheimer's disease, and that taking vitamin E supplements may lower the risk, so knowing a person's genetic predisposition could act as an incentive to take precautionary measures, Professor Tanzi told the meeting. "The hope at least is that we'll be able to predict the disease," he said.

Five genes are known to be involved in increasing the risk of developing Alzheimer's, and Professor Tanzi's team has found a sixth "candidate" gene which is strongly suspected of also playing an important role.

Scientists are already working on gene "chips" that can test people for a number of genes simultaneously, and which could lead to prototype screens for determining a person's inherited predisposition for developing Alzheimer's, explained the professor. "Within five years we'll have enough genetic information to build a reliable gene chip. We'll have reliable Alzheimer's testing easily within five years, but I can't say that we'll have the drugs to treat it by then," he said.