Experts Advise a Grain of Salt With Mail-Order Genomes, at $1,000 a Pop

| November 19, 2007

The Chicago Tribune (11/18) reported, "The revolution in human genomics is about to hit the street, at least for those able to pay about $1,000 for a glance at their entire genome." deCode Genetics, an Iceland-based company, unveiled deCODEme on Friday, a service that "will assess a person’s genome for disease risk, traits like eye color, and ancestral origins." To get the service, people only need "to send in a scraping of cells from inside the cheek and a check for $985."
      According to the New York Times (11/17, A16, Wade), deCODEme, and similar companies 23andMe and Navigenics are able to offer services that could exceed $1 million in cost by using an inexpensive alternative device called an SNP chip to decode "the three billion units of the human genome." The Times detailed that the deCODEme "will not test for the ApoE4 mutation associated with Alzheimer’s disease" or for genes linked to rare disorders, but rather "will use a chip that tests a person’s DNA at one million sites along the genome," and then compare that data "with the patients’ genotypes in its own and other databases that have been used in discovering disease-related SNPs." This comparison will then let the company "estimate a customer’s relative risk of developing the 20 or so common diseases for which disease-related SNPs have been identified." Other "genetic variants, discovered by its own and other scientists, that influence the color of a person’s skin, hair and eyes, or whether they are prone to freckles" will also be tested. So far, most SNPs "are linked to common diseases like cancer, diabetes and heart disease."
      The Financial Times (11/17, Cookson) detailed the method by which DeCODEme works. After customers "send in a cheek swab to DeCode," in a few weeks "they will be able to navigate around a password-controlled website to find out as much personal information as they want." However, any risks for diseases that the consumer does not want to look up will remain hidden from them. Dr. Kari Stefansson, DeCODEme’s CEO, "conceded the system could be abused: for example, by a subscriber who obtained someone else’s DNA by deception and then sent it in as his or her own." This raises privacy concerns, in addition to concerns others have raised about the method itself. "Critics of genomic testing say there is not yet enough scientific knowledge linking genetic variations to disease" For example, DNA sequencer "Craig Venter,…who has analyzed his whole genome in great detail, said he had found little useful information about his own health."
      In an article that appeared in Wired magazine (11/17), Thomas Goetz wrote, "Simply by spitting into a vial, customers of these companies will become early adopters of personalized medicine." Using these types of technology, people "will not live according to what has happened to us…nor according to what happens to most Americans," but rather, by "what our own specific genetic risks predispose us toward." Goetz continued, "The fact that any consumer with $1,000 can now capitalize on this project is a rare case of groundbreaking science overlapping with an eager marketplace." And, once "the price of sequencing the entire genome drops below $1,000, all six billion points of your genetic code will be opened to scrutiny." However, before acting "on this data, we first need to understand it."
      In the Science of Business blog on Forbes‘ website, Matthew Herper (11/17) also covered the story, as did the Money Times (11/18, Garg).

NYT Article by Nicholas Wade

The revolution in human genomics, still barely understood in the doctor’s office, is about to hit the street, at least for those able to pay about $1,000 for a glance at their entire genome.

The Icelandic company deCODE Genetics announced yesterday that it is now offering a service called deCODEme, which will assess a person’s genome for risk of common diseases, bodily traits like hair and eye color, and ancestral origins. Subscribers have to send in a scraping of cells from inside the cheek and a check for $985.

A similar service, using a smaller but custom-made analytic device, is being unveiled soon by 23andMe, a Google-financed company founded by Linda Avey, a biotechnology executive, and Anne Wojcicki, a health-care investor who is married to Sergey Brin, Google’s co-founder. The 23 in the company’s name refers to the 23 pairs of chromosomes in the human genome.

A third company, Navigenics, of Redwood Shores, Calif., is expected to focus on disease genes.

Unlike the present genetic testing and genetic genealogy companies, which look at a few specific genes, the new services will sample the whole human genome.

Many people may welcome the rich new trove of data about their hereditary make-up and ancestry, but genetic counselors are concerned that some people may find the information hard to handle, given that much of the current genetic knowledge is related to a person’s risk of developing common and often untreatable diseases.

The new services will use devices known as SNP chips, which offer a cheap substitute for decoding the three billion units of the human genome, a task that would probably cost $1 million or so per person at present.

DeCODE Genetics will not test the variants covered in most genetic tests, where a single change causes a specific disease with high certainty. These are mostly rare diseases. The common diseases, which the company will assess, are generally caused by several different mutations, each one of which confers a small extra risk. DeCODE will not test for the ApoE4 mutation associated with Alzheimer’s disease.

The chips, made by companies like Illumina of San Diego and Affymetrix of Santa Clara, Calif., are programmed to determine the DNA unit at sites along the genome which are known to vary from person to person. The chips thus capture the major points of difference, the single nucleotide polymorphisms or SNPs, pronounced “snips,” in an individual’s DNA while ignoring the many sites at which all people have the same DNA unit.

The deCODEme service will use a chip that tests a person’s DNA at one million sites along the genome. The company will then compare this set of data, known as a genotype, with the patients’ genotypes in its own and other databases that have been used in discovering disease-related SNPs.

From this comparison the company will estimate a customer’s relative risk of developing the 20 or so common diseases for which disease-related SNPs have been identified.

DeCODE will also test for genetic variants, discovered by its own and other scientists, that influence the color of a person’s skin, hair and eyes, or whether they are prone to freckles.

DeCODE will also examine two elements that pass essentially unchanged from one generation to the next: SNPs on the Y chromosome reflect the origin of a man’s ancestors back to 50,000 years ago when modern humans first left Africa, while those on the mitochondrial DNA track the wanderings of women throughout the globe.

Most of the SNPs studied so far are linked to common diseases like cancer, diabetes and heart disease. Because the diseases are common, many people possess the underlying SNPs. So any interpretation of a person’s genome is at present heavily skewed toward generating ominous news.

This may alarm some customers, even though they will never get most or any of the diseases for which they simply have some genetic risk. There are undoubtedly genes that promote longevity and good health but far fewer of these have yet been spotted.

Genetic counselors have long been concerned that the growing availability of genomic information will outpace the ability to interpret it. Genetic information affects not only the person for whom it is obtained but also their family members. And it cannot ever be changed.

“If people can go into this testing knowing what its limits are, and can take it with a grain of salt, that’s fine,” said Angela Trepanier, incoming president of the National Society of Genetic Counselors. “But you have to be really careful about what you know and don’t know.”

Elizabeth Balkite, a genetic counselor in Durham, N.C., said, “I don’t believe in keeping information from people but I’d be curious as to how useful this would be to the average individual.”

If the information is misunderstood, she said, the field will be set back.

Dr. Kari Stefansson, chief executive of deCODE Genetics, said the genotyping information his company would provide was not the same as a genetic test. If customers felt they were at particular risk of a disease, they should get a proper test from their physician, he said.

While the information should be handled carefully, Dr. Stefansson said, “The genetic counselors cannot deprive people of the right of genetic self-determination.”

DeCODE Genetics has genotyped thousands of patients in its search for genetic variants that lie at the roots of common diseases.

Dr. Stefansson said this expertise gives the company an advantage over other genotyping services in terms of accuracy, safeguarding privacy and the ability to interpret the information. 23andMe is using a smaller chip, one with only 650,000 SNPs, he said, although some of the test sites are tailored to generate information about population ancestry.

“They don’t have any track record in human genetics” and will be relying on others to do the genotyping, Dr. Stefansson said.

Ms. Wojcicki said in an e-mail message that she could not comment on deCODE Genetics’ announcement because she did not know the details of its service.

In September, J. Craig Venter, the pioneer of decoding genomes, published the almost full sequence of his DNA. But because so little is known about the meaning of variation at each site on the genome, there was not much of interest he could say about himself. Companies like deCODE hope that the more people have themselves genotyped, the better they will become at interpreting each DNA difference.


Category: Genetics

Comments are closed.