Author Archive for Luke Jostins

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Inbreeding, Genetic Disease and the Royal Wedding

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?

The genome hasn’t failed

On Monday, the Guardian published an article by plant geneticist Jonathan Latham entitled “The failure of the genome”. Ironically given this is an article criticising allegedly exaggerated claims made about the power of the human genome, Latham does not spare us his own hyperbole:

Among all the genetic findings for common illnesses, such as heart disease, cancer and mental illnesses, only a handful are of genuine significance for human health. Faulty genes rarely cause, or even mildly predispose us, to disease, and as a consequence the science of human genetics is in deep crisis.

[…] The failure to find meaningful inherited genetic predispositions is likely to become the most profound crisis that science has faced. [emphasis added]

The claim that human genetics is in crisis is not novel. Latham made an extended version of this argument in a blog post at the Bioscience Resource Project in December last year, which Daniel critiqued at length at the time, and which contained a schoolboy statistical error corrected by Luke. And Latham is by no means the only genome-basher out there: the 10 year anniversary of the sequencing of the human genome triggered a spate of “genome fail” pieces (see Nicholas Wade, Andrew Pollack, Matt Ridley, and a particularly horrendous example from Oliver James, for instance).

We suspect for most of our readers Latham’s rather hysterical critique will fall on deaf ears, but it is part of a bizarre and disturbing trend that needs to be publicly countered. Here are several of the places where Latham’s screed gets it patently wrong:

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Analysing your own genome, bloggers respond to the FDA and more reporting on bogus GWAS results

Razib Khan, more known for his detailed low-downs of population biology and history, has written an important post on Gene Expression, explaining in careful detail exactly how to run some simple population genetic analysis on public genomes, as well as on your own personal genomics data. The outcome of the tutorial is an ADMIXTURE plot (like the one to the left), showing what proportion of your genome comes from different ancestral populations. This sort of analysis is not difficult, but it can often be hard to know how to start, so Razib’s post gives a good landing point for people who want to dig deaper into their own genomes.

This tutorial also ties in to some political ideas that Razib has been talking about since the recent call to allow access to genomic information only via prescription. If you are worried about losing access to your genome, one option is to ensure that you do not require companies to generate and interpret your genome. As sequencing, genotyping and computing prices fall, DIY genetics becomes more and more plausible. Learn to discover things about your own genome, and no-one will be able to take that away from you. [LJ]

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People Have A Right To Access Their Own Genetic Information

This week has seen another FDA meeting seeking guidance on how to regulate direct-to-consumer (DTC) genetic tests in the US. The meeting itself has been covered by GNZ bloggers Daniel at Genetic Future and Dan at Genomics Law Report, and its apparent outcome has sparked furious debate elsewhere. The discussion among the “independent” panel convened at the meeting appeared to converge on the proposal that all health-related genomic tests should be ordered and reported through physicians. However, the outcomes of the meeting in terms of FDA policy remain unclear, and one FDA official has indicated that decisions about the availability of genetic tests will be made on a test-by-test basis.

There is no doubt that the appropriate regulation of personal genomics tests is a complex issue, and there is a diversity of opinion about how best to achieve it within GNZ (as there is throughout the genomics community). However, there are several points we agree on:

  • Individuals have a fundamental right to access information about themselves, including genetic information. While it is important to also consider the accuracy, interpretation, validity and utility of tests, this underlying principle should guide policy.
  • There is currently no evidence that DTC genetic tests pose a danger to consumers. A recent study of over 2,000 participants in DTC testing concluded that “testing did not result in any measurable short-term changes in psychological health”. In the absence of any evidence of harm there is no justification for restricting individual autonomy.
  • DNA does not have magical powers, and does not require special treatment simply by virtue of being DNA. Genetic exceptionalism – the idea that genetics must be treated as special under the law – is an inappropriate basis for policy-making. Tests should be regulated appropriately based on their predictive power, utility and potential for harm, all of which are related concepts.
  • As DNA sequencing becomes cheaper, the line between medical and non-medical testing will continue to blur. Excessive regulation of health-related genetic tests could also unncessarily hinder the ability of people to access their entire genome sequences for other purposes (such as genetic genealogy).
  • Most clinicians do not have the appropriate knowledge to interpret genomic tests, particularly in healthy individuals. This point is almost universally agreed, even by the FDA, and has certainly been the experience of some of the GNZ members upon taking our genetic results to doctors. Physicians in general are therefore a strange choice for ‘guardians of the genome’.
  • Most early adopters of DTC genetic tests are sufficiently well-informed to understand the implications of a genomic test and interpret the results correctly. Putting a general physician between these informed individuals and their own genomes is paternalistic and unnecessary.

While the outcome of the FDA’s deliberations remain uncertain, it is clear that there will be intensive lobbying against any attempt at excessive legislation. In the worst case scenario, the fledgling and innovative personal genomics market could be crushed by the FDA. However, there is still plenty of room for a measured approach that enforces test accuracy, punishes false claims and promotes informed choices by consumers, without reducing the ability of responsible companies to continue to operate and innovate.

We urge others in the genomics community to make their voices heard on these issues. Let the FDA – and, if you’re based in the USA, your political representatives – know that regulation of genetic testing should be based on evidence, not fear, and that any attempt to unreasonably restrict your access to your own genetic information is unacceptable.

Inbreeding around the world, gene-environment interactions and sales of genetic tests

The picture above shows the relatedness of parents across different populations throughout the world; for reference, 0.065 is the average value for a first cousin mating. It comes from a paper out in pre-publication this week at the European Journal of Human Genetics, which estimates the level of inbreeding (or “consanguinity”) of parents by looking for sections of the genome where individuals inherit an identical piece of DNA from each parent. Such “runs of homozygosity” are a sure sign of inbreeding, as both parents will have inherited the bit of DNA from a recent common ancestor: the number and length of these sections can be used to find out how many generations ago the common ancestor lived, i.e. how closely related the parents were (cousins share a grandparent, second cousins a great-grandparent, and so on). In the plot above, we can see a high degree of cousin-marriage in Middle-Eastern cultures, and somewhat more sadly, high degrees of inbreeding in the Native American populations, due to the collapse in their population sizes. [LJ]

For those interested in gene-by-environment interactions the latest issue of Trends in Genetics includes a review article by Carole Ober and Donata Vercelli on the challenges of this area, illustrated by examples from asthma research. In particular they highlight the difficulties of moving G-by-E studies from examination of known candidate genes to genome-wide association. More interactions, this time of the protein-by-protein kind, are the subject of an article by Soler-Lopez et al. in this month’s Genome Research. They looked for interactions relating to Alzheimer disease using a combination of computational and experimental strategies, identifying 66 genes that putatively interact with known AD-related genes. The authors focus on the potential roles of neuronal death regulation and pathways linking redox signalling to immune response in AD pathology. [KIM]
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Defining a complete genome, innovative sequencers, and the mess ahead for personalised medicine

The Archon X Prize for Genomics offers a $10 million prize to to the first team that can sequence 100 human genomes within 10 days or less at a total cost of $10,000, with strict criteria for accuracy and completeness. However, given that there aren’t currently any gold standard genomes that could be used to confirm that a team has met the Prize’s requirements, and the complexity of judging the winner is far greater than for any previous award from the X Prize Foundation. To help refine the validation process, the Prize Foundation has just announced a collaboration with Nature to crowd-source ideas, which can be submitted via comments on the current plan over at Nature Precedings. If you’re interested in helping to define the state of the art in human genome construction, head over and have your say. [DM]

This week MIT’s Technology Review released this year’s TR50, a list of the 50 most innovative companies. Biomedical companies make a good showing, with 8 in total. Excitingly, three of these companies have been chosen for innovations in DNA sequencing technology; Complete Genomics, for developing the service approach to sequencing human genomes, Life Technologies for aquiring the new Ion Torrent machine, and Pacific Biosciences for their single-molecule sequencing machines. [LJ]

Over at Forbes, Matthew Herper pointed out the announcement of an exciting new targeted drug for cystic fibrosis that showed greater than expected results in clinical trials, as well as the announcement by Life Technologies of an impending upgrade to their Ion Torrent sequencing platform (also comprehensively dissected by Keith Robison here and here). This all sounds like good news, but Herper warned in a separate post that the implications of recent developments in genomics and pharmaceuticals might be heading towards a chaotic impact:
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Predicting lupus outcomes, US biomedical funding battles and telling children about genetic disease

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]

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Ulcerative colitis genetics, Nature on the human genome

Yes, it’s Friday Links time yet again here at Genomes Unzipped.

A paper in Nature Genetics this week reports the results of a large meta-analysis of GWAS studies into ulcerative colitis, which more than doubles the number of loci known for the disease from 18 to 47. This pushes the proportion of heritability explained from 11 to 16%, and sheds more light on the shared and non-shared pathways between ulcerative colitis and Crohn’s disease, along with the interplay with other immune and inflammatory disorders.

The lead author is a Genomes Unzipped contributor, but he emphatically refused to contribute to this Friday Links post, on the grounds that he doesn’t want to blow his own trumpet. So, instead, here is a quote from the Sanger Institute’s press release:

“The genomic regions we have identified give us an insight into the biology underlying ulcerative colitis,” says Dr Carl Anderson, from the Wellcome Trust Sanger Institute and first author on the paper. “These important initial discoveries are the building blocks on which we can begin to derive better IBD treatments, though much further work is needed before these become a clinical reality.” [LJ]

Nature has a special issue this week devoted to the decade of progress since the publication of the human genome sequence. Eric Lander, who was first author on the original Human Genome Project paper, has a long and thoughtful commentary on the subsequent impact of that publication across a wide range of fields. Elaine Mardis accompanies Lander’s piece with a discussion of the astonishing advances in sequencing technology over the last decade (including a figure that emphasises the tremendous impact of the development of the Solexa/Illumina Genome Analyzer platform, which boosted sequencing capacity by eight orders of magnitude in a single year!).

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A decade of genomics, 60 new genomes, parenthood and sharing genetic data, and more on data return

To celebrate 10 years since the back-to-back publications of complete human genomes in Science and Nature, Science has published series of articles looking back at the last 10 years of genomics, and forward to the future. The article contains short essays from Francis Collins and Craig Venter, the former talking about some of the successes of medical sequencing (including giving a name and photograph to the exome-sequenced IBD patient I discussed a few weeks ago), and the latter discussing how far we still have to go before genomics can reach its potential. Baylor’s Richard Gibbs talks about how the large-scale technical discipline of genomics and the biological subject of genetics are starting to re-merge, after the Human Genome Project saw the two diverging, and there is an oddly inspiring comment from theologian Ronald Cole-Turning about how genomics is redefining our vision of humanity.

Of particular interest is an article by Eliot Marshall on why genomics hasn’t yet had a large effect on medical practice, and what needs to be done to allow the genomic revolution to trickle into medical care. He argues that scientists and doctors need to meet each other half way; scientists need to focus more on showing the direct clinical utility of genomics, whereas doctors need to be more ready to accept new technologies and discoveries, and adapt the way they practice medicine to make full use of them. [LJ]

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Cluster Sequencing with Oxford Nanopore’s GridION System

More on nanopore sequencing this week. I mentioned in my Genetic Future post that the UK sequencing company Oxford Nanopore is somewhat of a dark horse, and an agreement with Illumina has required complete silence about their potential DNA sequencing machines. However, this wasn’t strictly true; Illumina has signed an agreement for the exonuclease sequencing technology, and on that we aren’t likely to hear anything until it is ready.

However, Oxford Nanopore still can, and does, talk about other aspects of their technology. And today, they have released information on their website on the GridION platform, which will be used to run all their nanopore technology (including DNA sequencing and protein analysis). In effect, these are details about the sequencing machine, but with no new specifics about the sequencing process itself.

Here are a few first impressions.

Sequencing in Clusters

The machines are small and low-cost; I expect they will cost the same or less than an Ion Torrent machine. Like the Ion Torrent, MiSeq and GS Junior, the Nanopore machines should be suitable to sit on the bench of a small lab, running small projects and with small budgets and floorspace.

However, this isn’t the full story. Each individual machine is rocking the VCR-machine-circa-1992 look, and the reason for this becomes clear when you see many of them together. The boxes are designed to fit together in standard computing cluster racks, and Oxford Nanopore refer to each of the individual machines as “nodes”. The nodes connect together via a standard network, and can talk to each other, as well as reporting data in real time through the network to other computers. When joined together like this, one machine can be designated as the control node, and during sequencing many nodes can be assigned to sequence the same sample.

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