I have no strong family history of any disease, despite having 7 blood aunts and uncles and countless cousins. So when I sent my spit off to 23andMe at the start of the Genomes Unzipped project, I was expecting something very similar to Caroline’s experience: a 5% increase in risk here, a 2% decrease in risk there, nothing that would really tell my anything about my health.
However, this was not my experience. Along with a pretty interesting Y haplogroup, I also had three unexpected and potentially worrying health results. I am a cystic fibrosis carrier, a hemochromatosis compound heterozygote, and have a strongly elevated risk of age-related macular degeneration. This cocktail of genetic disease certainly was not what I came to the test expecting!
After some thinking, I decided to take my test results to my GP, and see if there was any advice or testing he would recommend. In the end, my GP referred me to a clinical geneticist, which started a cascade of appointments which in turn led to a number of important changes in how I treat my own health.
What was most interesting is how the whole experience got me thinking about my health as something I am in charge of. I have since made a number of important life-style changes, some of them directly related to my genotyping results, some more generally to improve my overall health.
The point of this post is just to go through some of the experiences, what I have learned about specific conditions, and what changes I have made to my life since. In some sense, I feel like my experience is a case-study in what good outcomes can come from personal genomics, both for specific conditions, and more generally for how genetic data can change your own approach to your health.
Continue reading ‘A case study in personal genomics’
Today is, of course, the day of the Royal Wedding, with new blood entering the British royal line, and the hope of new heirs to our throne. And of course the question on the lips of all British geneticists is: will there be any new royal genetic diseases in this crop? The European royal lines have always been prone to the odd loss-of-function mutation. An unlucky mutation in Queen Victoria’s Factor IX gene caused a nasty case X-linked Haemophilia B in her male descendants (a mutation that was only mapped in 2009 by sequencing the bones of the murdered Romanov branch). Luckily for them, this mutation hasn’t been observed in any of Victoria’s descendants lately; while it can hide undetected in women, this obviously doesn’t apply to William. More systemic genetic problems have been the result of heavy inbreeding; Charles II of Spain, with his distressingly bushy family tree (left), suffered from severe Habsburg jaw, along with a host of other genetic complaints.
In terms of inbreeding, there has been a bunch of digging around in the press to find the closest common ancestor of William and Kate: Channel Four turned up fourteen and fifteenth cousinships, and the Daily Mail managed to find a eleventh cousinship. For comparison, William’s parents Diana and Charles were also 11th cousins, and the Queen and Prince Philip were a far more regal 2nd cousins once removed. Eleventh cousins share on average 60-parts-per-billion of DNA, or about 180bp (although with wide variation due to the spotty nature of meiotic recombination: in fact, 99.5% of 11th cousins will share no stretches of DNA through recent descent at all, while the remaining 0.5% will typically share tens of thousands of bases). Given that the average person harbours about 10 recessive diseases, this gives about a 1 in 1.6 million chance of Kate and Will’s offspring developing a royal disease due to a piece of DNA shared between them. So, not very likely then.
In fact, eleventh cousins is a pretty low degree of relatedness, by the standard of these things. A study of inbreeding in European populations found that couples from the UK are, on average, as genetically related as 6th cousins (the study looked at inbreeding in Scots, and in children of one Orkadian and one non-Orkadian. No English people, but I would be very suprised if we differed significantly). 6th cousins share about 0.006% of their DNA, and thus have about a 0.06% chance of developing a genetic disease via a common ancestor. Giving that the Royal Family are better than most at genealogy, we can probably conclude that the royal couple are less closely related than the average UK couple, and thus their children are less likely than most to suffer from a genetic disease. Good news for them, bad news for geneticists, perhaps?
There are a pair of papers in PLoS Genetics that shine some light on the effect of common GWAS variants on complex traits. The first investigates the effect of 22 common variants on sub-phenotypes of systemic lupus erythematosus, in how well a model including clinical measures plus GWAS variants can predict specific complications of lupus, over a model including just clinical outcomes. In some cases, there is little improvement (GWAS variants add nothing to prediction of renal failure, for instance), but in many there is a measurable improvement (such as for hameatological disorder and oral ulcers, the former of which is largely unpredictable from clinical outcomes). The second paper is a breakdown of the effect of the common obesity-associated variant FTO on BMI across age ranges; we see an interesting effect, whereby the variant that causes an increase in BMI in older children actually causes a fall in BMI in children under the age of 2. [LJ]
It’s budget battle season in the United States, and biomedical research funding looks likely to be caught in the crossfire. President Obama has proposed a $745 x 106 increase in the NIH budget, bringing it to $31.8 x 109 in total. This wouldn’t quite keep up with inflation, leading to a slight decrease in grant success rates from America’s largest biomedical research funder. The Republican-controlled House of Representatives, by contrast, has slashed the NIH budget by $1.6 x 109 in their proposed budget (bill HR1), which would be a heavy blow to research funding. Of course, scientists, non-crazy editorial writers and activist groups have been rallying around protecting research funding (in the NIH and beyond). Unfortunately I wouldn’t expect a speedy resolution, as veteran US politics blogger Nate Silver likens the whole situation to Zugzwang. [JCB]
Continue reading ‘Predicting lupus outcomes, US biomedical funding battles and telling children about genetic disease’
A quick note about the Reader Survey; we are going to stop taking responses at the end of Saturday (Pacific Time). If you haven’t already done so, please fill out the survey now.
A couple of interesting articles this week on the Personal Genome Project and public genomics in general. Mark Henderson at the Times has an opinion piece (behind a paywall, I’m afraid) about Misha Angrist‘s book Here Is A Human Being (see also this review from The Intersection), and in the Duke Magazine Mary Carmichael has an in-depth feature on the work of George Church, with some interesting history of the early days of the PGP.
One aspect that comes out of these articles is how those who take part in public genomics projects are starting to own the unknown unknowns. They accept that they cannot anticipate all the risks of making their data public, but are willing to take the risk of exposing themselves to these unknown risks, and in doing so turn them into knowns. Another aspect is the sheer number of individuals who want to sign up to have their data published online: 15,000 people have expressed interesting in being part of the PGP, despite initial NIH concerns the no-one would want to take part at all. This also chimes with research presented at ASHG this year, showing that members of the public are more concerned with contributing to scientific knowledge, and, crucially, getting access to their own genetic data than they are about the potential risks that such data could expose them too. [LJ]
Continue reading ‘Friday Links’
The story behind this post is that my wife recently gave birth to our first son and we experienced a funny story about genetics the day following the birth. Before I start I should say, to reassure the reader, that I have no doubt that I am indeed the father of my child. But as you will see, a non-geneticist might have become worried when faced with the same situation.
Firstly, my wife has a negative rhesus type. This has important medical implications because if the baby were to have a positive rhesus type, she would create antibodies against this marker which could be life-threatening for any subsequent child of positive rhesus type. Basically this is a relatively big deal, but there are ways to deal with this, and therefore knowing the blood type of the baby is essential.
The day after the birth, while we are both lying on our bed, very tired, a midwife comes by and asks us whether we know the rhesus status of the baby. We answer negatively, she checks her notes and says, “Ah, good news, the baby is rhesus negative. The father must also be rhesus negative then!” Well, I am not…
Continue reading ‘Rhesus, paternity tests and 23andMe’
Two exciting-looking new science blogging collectives have been announced this week. The Public Library of Science launched a new blogging collective, including personal genomics blogger Misha Angrist, and the Guardian newspaper has launched its Guardian Science Blogs network, including Dr Evan Harris, ex-MP for Oxford West and long time supporter of the role of science in public policy. I’m pretty excited about these new blogs, but it does stand to increase my RSS load significantly. [LJ]
In this month’s issue of European Journal of Human Genetics, Yang, Visscher and Wray contribute to the discussion around the aetiology of common complex diseases. They demonstrate that the existence of a large number of sporadic cases (instances where a patient has no first, second, or third-degree relatives with the disease) is not incompatible with a polygenic model of disease. A little less hot-off-the-press are two opinion pieces on genetic testing regulation from the August issue of Nature. Arthur Beaudet argues that stringent government regulation should be applied to genotyping/sequencing, and interpretation should be the exclusive domain of the medical profession. Gail Javitt takes a different view, arguing that genetic tests to be treated in the same way as other medical tests and that the level of regulation imposed should be determined by medical relevance of the outcome. [KIM]
Finally, Procreation News; our very own Daniel MacArthur and Ilana Fisher have recently given birth to a baby boy (the picture to the left may be a little out of date). Daniel made the announcement on Twitter, and also had this to say:
After careful inspection, I’ve decided that my six-day-old son is the most remarkable human being to have ever lived.
Due to double blinding, neither we nor Daniel know whether he has an actual or placebo baby, so we can’t yet assess the significance of this claim. Watch this space! [LJ]