Posted by dj on July 13, 2000, at 11:05:14
In reply to Re: Stress, Depression role of ADs, posted by dj on July 13, 2000, at 10:50:30
Doctor warns of 'hype' in genome decoding
By Richard Saltus, Globe Staff, 7/13/2000
Promises of a medical revolution in which common diseases will be predicted - and even prevented - through gene tests are largely ''geno-hype,'' contends a Johns Hopkins University expert, arguing that scientists have oversold the likely health value of decoding the human genome.
As for biotech companies investing millions in search of genetic differences linked to major diseases, ''I think they are barking up the wrong tree,'' said Dr. Neil A. Holtzman, a pediatrician and medical policy specialist, in an interview.
Holtzman, lead author of an opinion piece in today's issue of the New England Journal of Medicine, said he was reacting to grandiose claims made by scientists and officials involved in sequencing, or identifying, the human genetic code.
A publicly funded US project and Celera Genomics Inc. last month announced they had identified and cataloged most of the set of human genes. In addition to learning how genes work in the body, many scientists said the genome decoding would bring about a ''revolution in medicine.''
''The new genetics will not revolutionize the way in which common diseases are identified or prevented,'' said Holtzman in the article, co-authored by Theresa M. Marteau, a psychologist at King's College in London. Holtzman chaired a task force on genetic testing for the Department of Health and Human Services.
But other scientists were quick to say they thought Holtzman missed the major point.
''If Holtzman means there are many overly simplistic notions about how genetics will be implemented in medicine, he's right,'' said Eric Lander, director of the MIT-Whitehead Institute genome sequencing center in Cambridge. ''But if he thinks that understanding the genetic basis of disease won't revolutionize medicine, he's simply wrong.''
The authors of today's article directed most of their criticism not at what would be learned from the human genome, but at the idea that predictive testing will be feasible and widely used. They said scientists have spent years looking for genes that strongly influence whether or not a person would get such illnesses as schizophrenia, manic depression, and asthma, but with little success.
''Most people will have little interest in learning their genotype [individual pattern of genetic variations],'' especially if the gene tests don't have great predictive power and there aren't effective methods of preventing the diseases, said the authors.
While it may be possible to find variations between people's DNA that match their susceptibility to diseases, Holtzman says the links generally won't be strong enough to be useful in predicting diseases caused by many genetic and environmental factors. Or, if there is a strong effect - like the BRCA1 and 2 genes causing a markedly increased risk of breast cancer - such genes are likely to be found only in a small percentage of individuals with the disease. Only one-quarter of one percent of women carry those genes, said Holtzman.
Holtzman said another hoped-for outcome of the genome project - finding genetic variations that predict whether individuals will react well or badly to certain drugs - is potentially achievable.
But he termed ''not very realistic'' often-cited scenarios in which infants could have their entire set of genes tested to determine what diseases they would be susceptible to - and even at what age they would die.
Yet prominent scientists, as well as start-up biotech company officials, have conjured such visions in the euphoria over the near-completion of decoding the human genome, said Holtzman and Marteau.
''We had the head of the Wellcome Trust [a London health philanthropy] saying this was the greatest thing since the invention of the wheel,'' said Marteau in a telephone interview.
In the United States, Dr. Francis Collins, head of the publicly funded genome project, has said that reading out all the genetic scripts in our cells will ''change the way medicine is practiced'' and ''could bring new treatments for every single disease.''
Gene scientists and biotech firm officials agreed that the genome project has been hyped - and they blamed the media as well as scientists and government officials - but they said Holtzman's arguments were flawed.
Jonathan Rothberg, chairman and CEO of CuraGen Corp. of New Haven, said that even if genome information doesn't lead to powerful predictive tests, it is already making it possible to develop better drugs.
For example, he said, discovering the underlying genetic problem in children with a rare form of high cholesterol has led to cholesterol-lowering drugs like Lipitor that are helpful to millions of people with more-common (but less severe) cholesterol problems.
Alan Gutmacher, senior clinical adviser to Collins, the genome project director, agreed with Holtzman about ''geno-hype,'' but added, ''it's a very tough thing to try to remove the hyperbole while still including the real wonder and the awesome power'' of sequencing the genome.
This story ran on page A9 of the Boston Globe on 7/13/2000.
© Copyright 2000 Globe Newspaper Company.
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