pre-natal genetic diagnosis
dgmacarthur | January 13, 2011In the last century infant mortality has declined precipitously in the Western world, thanks in large part to the development of antibiotics and vaccination. Yet as the suffering and death from infectious disease has reduced, the burden from genetic disease has become proportionately greater: currently around 20% of all infant deaths in developed countries are a result of inherited Mendelian (single-gene) disorders.
What can be done to reduce this burden? Increasingly sophisticated methods for detecting disease in embryos during pregnancy will help, and these have recently taken another step…
sb admin | January 11, 2011Software company 5AM Solutions has just launched a neat little FireFox plug-in for customers of consumer genomics company 23andMe.
The idea is very simple:
Download your raw data from 23andMe (or use one of the files from me or my colleagues at Genomes Unzipped);
Install the plug-in from here and point it to your 23andMe data;
Browse to a website discussing one of the genetic variants included on the 23andMe chip, and you'll see highlights around the rsID of any variant on the page (rsIDs are unique codes assigned by dbSNP to most of the common variants targeted by personal genomics…
sb admin | January 7, 2011As part of his Gene Week celebration over at Forbes, Matthew Herper has a provocative post titled "Why you can't have your $1000 genome". In this post I'll explain why, while Herper's pessimism is absolutely justified for genomes produced in a medical setting, I'm confident that I'll be obtaining my own near-$1000 genome in the not-too-distant future.
Matt's underlying argument is that while sequencing costs will continue to drop, obtaining a complete genome sequence that is sufficiently accurate for medical interpretation will require additional expenses (increased sequence coverage to…
sb admin | December 15, 2010Late last week I stumbled across a press release with an attention-grabbing headline ("The Causes of Common Diseases are Not Genetic Concludes a New Analysis") linking to a lengthy blog post at the Bioscience Resource Project, a website devoted to food and agriculture. The post, written by two plant geneticists, plays a tune that will be familiar to anyone who has encountered the rhetoric of GeneWatch UK: basically, modern genomics is pure hype perpetuated by scientists seeking grant money and corporations seeking to absolve themselves of responsibility for environmental disasters.
The…
sb admin | December 3, 2010A reminder to anyone who reads my other blog Genomes Unzipped that we have a reader survey underway there now, which includes some questions about genetic testing experiences and attitudes towards genetics. We're closing the survey to responses this weekend, so if you're an Unzipped reader but haven't had a chance to fill in the survey, please do so now.
sb admin | November 24, 2010Update 30/11/10: 23andMe has extended their 80% discount until Christmas, without a need for a discount code.
Personal genomics company 23andMe has made some fairly major announcements this week: a brand new chip, a new product strategy (including a monthly subscription fee), and yet another discount push. What do these changes mean for existing and new customers?
The new chip
23andMe's new v3 chip is a substantial improvement over the v2 chip that most current customers were run on (the v2 was introduced back in September 2008). Firstly, the v3 chip includes nearly double the number of…
sb admin | October 12, 2010
Back in June I launched a new blog, Genomes Unzipped, together with a group of colleagues and friends with expertise in various areas of genetics. At the time I made a rather cryptic comment about "planning much bigger things for the site over the next few months".
Today I announced what I meant by that: from today, all of the 12 members of Genomes Unzipped - including my wife and I - will be releasing their own results from a variety of genetic tests, online, for anyone to access. Initially those results consist of data from one company (23andMe) for all 12 members; deCODEme for one…
dgmacarthur | January 22, 2010Disclaimer: my wife and I have both received and used free testing kits from Counsyl.
Counsyl is a rather enigmatic player in the personal genomics field: apart from a brief mention in Steven Pinker's excellent NY Times piece over a year ago and an even briefer post on a Newsweek blog late last year, the company has been in determined stealth mode for much of the last two years.
All that was publicly known about the company when I wrote about them last year was that they will be offering a large-scale carrier screening test: basically, allowing couples who are considering having a baby to…
dgmacarthur | April 30, 2009For those who have been too distracted by swine flu to notice: shares of the biotech company Sequenom have plummeted by 77% after the company announced that the extremely promising initial results for its SEQureDx Down syndrome test - which is designed to detect Down syndrome fetuses using blood samples from pregnant women - were "questionable" and had been mishandled by employees.
GenomeWeb Daily News reports:
As of early February, Sequenom had released data on
its SEQureDx test from a total of 858 samples. It said that the
positive predictive value was 96.6 percent, and the negative…
dgmacarthur | April 24, 2009Associated Press reports that Germany will likely soon pass regressive laws limiting the use of genetic testing:
The German parliament approved legislation Friday limiting the use
of genetic testing in an effort to prevent the technology's abuse.
The law, which was debated for more than seven years, must still go
before the upper house of parliament, but it is not expected to meet
any resistance.
Under the law, genetic tests can only be carried out by a doctor
and require the full consent of all parties involved. That makes it
illegal to conduct anonymous paternity tests and anyone found in…
dgmacarthur | April 9, 2009There are a couple of things I didn't explain very well in my previous post about the strange case of the 13-year-old girl suing a sperm bank using product liability law, on the grounds that the sperm used to conceive her carried a genetic defect resulting in her mental retardation.
First and foremost, what's with a girl inheriting Fragile X Syndrome from her father? This syndrome is (as you might expect) caused by mutations in a region located on the X chromosome, and the classic pattern of inheritance of X-linked diseases is that males are affected while females are "carriers" (who may also…
dgmacarthur | April 9, 2009New Scientist reports that a 13-year-old girl with Fragile X Syndrome - a severe genetic disorder - is suing the sperm bank that provided the sperm that led to her conception.
Curiously, the legal issue hinges on "a product liability law more commonly associated with manufacturing defects, such as faulty car brakes":
Donovan does not have to show that Idant was negligent, only that the
sperm it provided was unsafe and caused injury. "It doesn't matter how
much care was taken," says Daniel Thistle,
the lawyer representing Donovan, based in Philadelphia, Pennsylvania.
Genetic tests have…
dgmacarthur | March 22, 2009Yesterday I pointed to an article by New Scientist editor Michael Le Page advocating routine carrier testing for severe disease genes in parents-to-be, followed by IVF and pre-implantation genetic screening of embryos for couples unfortunate enough to both be carrying mutations in the same gene. I asked for well-reasoned objections to this approach from commenters.
Razib responded with a post at Gene Expression. Firstly, he pointed out that well-reasoned objections are not what matters in this debate:
...though reason is the "front side of the house" in this discussion, the
real work is being…
dgmacarthur | March 21, 2009A couple of weeks ago I pointed to an article by bioethicist Jacob Appel arguing that genetic screening for severe disease mutations should be mandatory for parents undergoing IVF, and that not doing so is tantamount to child abuse.
Today the same theme is taken up by New Scientist biology editor Michael Le Page, but extending the process to all parents-to-be via carrier testing:
All would-be parents should be offered screening to alert them to any
genetic disorders they risk passing on to their children. Those at risk
should then be offered IVF with pre-implantation genetic diagnosis
(IVF-…
dgmacarthur | March 10, 2009Fan Liu, Kate van Duijn, Johannes R. Vingerling, Albert Hofman, André G. Uitterlinden, A. Cecile J.W. Janssens, Manfred Kayser (2009). Eye color and the prediction of complex phenotypes from genotypes Current Biology, 19 (5) DOI: 10.1016/j.cub.2009.01.027
In a recent post I noted that genetic tests to predict adult height are still a long way off being accurate; currently, known genetic variants can predict just over 5% of the variance in height, as opposed to 40% predicted using a simple algorithm based on the heights of both parents. The genetic complexity of height means that trying to…
dgmacarthur | March 6, 2009Over at Opposing Views, bioethicist Jacob Appel argues that pre-implantation genetic screening for severe disease mutations should be compulsory for parents undergoing IVF.
Appell dodges one obvious criticism of this suggestion - that it unacceptably limits parental autonomy - by pointing out that "Western societies have long acknowledged that parental authority cannot undermine the medical interests of a child". As examples, Appell cites the facts that Jehovah's Witnesses cannot deny their own children blood transfusions, however strong their religious opposition, and that "American courts…
dgmacarthur | March 5, 2009Last month I mentioned a US fertility clinic that was offering couples undergoing IVF the opportunity to screen their embryos for sex, and for genes associated with "cosmetic" traits such as eye and hair colour. I used this as an opportunity to note that the genetic complexity of many traits (e.g. height, also discussed yesterday) would make it highly unlikely that embryo screening would be effective for these, although for hair and eye colour such screening is certainly feasible.
The media coverage of this fertility clinic - run by reproductive endocrinologist Jeff Steinberg (pictured) -…
dgmacarthur | February 1, 2009Edited 2/2/09: The cited study discusses pre-natal genetic screening, not only embryo screening; I've updated some wording to reflect this, but it doesn't have any major impact on the overall message.
Razib points to an article suggesting that Australian couples are "flocking" to a US fertility clinic that allows them to screen their potential IVF embryos for sex and even cosmetic traits like skin and eye colour, in addition to variants that predispose to severe disease risk. ("Flocking", in this context, means about 14 couples a month.)
This follows on the heels of a fairly widely-publicised…
dgmacarthur | January 13, 2009Following the dramatic appearance of the field of personal genomics just over a year ago the major players in the field have worked hard to distinguish themselves from their competition: 23andMe has emphasised the intellectual joy of learning about genetics, and also attempted to actively engage its customers in the company's research projects; deCODEme has leaned heavily on the impressive academic credentials of its parent company, deCODE Genetics; Navigenics has committed itself utterly to an image of sober, responsible reflection on the medical information present in its customers' genomes…
dgmacarthur | October 12, 2008
Nature News has an intriguing article
on the next three decades of reproductive medicine: essentially a
series of short musings from scientists working in the field about the
issues we will be facing in 30 year's time.
It's worth reading through in full, but this statement from Susannah Baruch at Johns Hopkins caught my eye:
There's
speculation that people will have designer babies, but I don't think
the data are there to support that. The spectre of people wanting the
perfect child is based on a false premise. No single gene predicts
blondness or thinness or height or whatever the 'perfect…