Author: By Steve Connor, Science Editor
The cost of sequencing the three billion letters of the human genome was only
a few years ago priced in the region of many tens of millions of pounds but
Professor Stephen Quake of Stanford University in Palo Alto, California has
done it for less than $50,000 (£31,000).
Using a revolutionary technique that he helped to pioneer six years ago,
Professor Quake has produced a “working draft” of his own genome that
medical scientists can now analyse for genetic predispositions to physical
and mental disorders and traits, as well as possible adverse reactions to
Fewer than a dozen people have had their entire genomes sequenced but all of
these DNA blueprints have, until now, cost many hundreds of thousands of
dollars and many hundreds of hours of expert labour and costly laboratory
time, putting the practice well out of reach of ordinary citizens and the
National Health Service.
However, Professor Quake said that there was nothing to stop advances in
genetics refining the technique still further to make it cheap enough for
ordinary people to use as an aid to medical diagnosis and treatment.
Proponents of such genetic screening believe it will lead to the development
of “personalised medicine”, when treatment is decided on the basis of a
person’s individual genetic make-up, rather than a “one size fits all”
When the Human Genome Project ? the international effort to decipher the
entire DNA of all human chromosomes ? was established in 1990, the cost of
working out the full genetic blueprint of a typical genome was estimated to
be about $3bn (£1.8bn). By the time the first draft of a composite genome
made from many different people was published in 2001 the cost had fallen
Last year, James Watson, who in 1953 co-discovered the double helix structure
of DNA with Cambridge colleague Francis Crick, had his own genome sequenced
for less than $1m, but it still entailed of army of technicians and a
massive investment in expensive laboratory equipment. Professor Quake said
that he managed to sequence his own genome in two months with the help of
just two colleagues.
“This is the first demonstration that you don’t need a genome centre to
sequence a human genome. It’s really democratising the fruits of the genome
revolution and saying that anybody can play this game,” Professor Quake said.
“This can now be done in one lab, with one machine, at a modest cost. It’s
going to unleash an enormous amount of creativity and really broaden the
field. Some of the doctors are starting to poke and prod me to see how they
can couple by genome with medicine,” he said.
One of the earliest findings from his own genome sequence is that Professor
Quake has inherited a rare mutation associated with an increased risk of
developing heart disease, which could explain observations he and other of
his family members have made about the health of prior generations.
“If you know your uncle had something, you kind of discount that you can get
it, but to see you’ve inherited the mutation for that is another matter
altogether,” he said.
Genome sequencing usually involves making many copies of a person’s DNA before
the detailed breakdown of each letter of the four-letter code can be done.
However, Professor Quake’s invention ? published in the journal Nature
Biotechnology ? can carry out the sequencing on a single DNA molecule from
an individual, making it far simpler and cheaper than the standard method.
One of the reasons why the method is so cheap is that it could use the
information gleaned by the Human Genome Project on what a typical genome
looks like. This enabled the scientists to compare the individual sequences
from Professor Quake’s fragmented pieces of DNA to build up a picture of his
overall genetic code.
But Professor Quake warned that the advent of cheap genome sequences ? a
central feature of the cult 1997 film Gattaca, set in a fictional future
when everyone is judged on their genetic makeup ? could lead to a new set of
ethical problems that have yet to be addressed by society.
“The $1,000 genome is just around the corner, and when everybody will be able
to have their genome sequenced, what’s it going to mean for privacy, health
insurance and decisions about human health? The technology is not going to
let people escape these ethics and policy questions,” Professor Quake said.
“Are we going to require people, based on their genetic inheritance, to modify
their behaviour, or just suggest it? Your insurance company could ask you to
have a certain diet or they’re not going to cover you. Is that what we
want?” he said.
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