Archive for the 'Guest Posts' Category

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Guest post by Razib Khan: My personal genome

I’ve been following Razib Khan’s scholarly and analytical exploration of his family’s genetic history – using data from 23andMe – over at Gene Expression with increasing fascination. When last week he noted that his findings appeared to be (finally) converging on a consensus, I asked if he’d be willing to summarise his journey for Genomes Unzipped readers. Here it is. –DM.

I’ve always been interested in genetics, anthropology, and history. Many may perceive me to be a collector of obscure facts, but summing up infinitesimals does produce something substantial in aggregation. One of the most influential books in my life has been History and Geography of Genes. So with that, the shift from classical markers to uniparental lineages, and now to the dense SNP-chips, has been a boon for my own intellectual interests which reside in part at the intersection of history and population genetics.

However, I’ve never been deeply curious as to the history of my own personal genome. I’m not adopted. All four of my grandparents were ethnic Bengalis, albeit from relatively diverse communal backgrounds. I look typically South Asian. Genealogy has never been a family fascination, and I’m going to be honest and admit that until five years ago I didn’t even know the names of my grandparents (in the Bengali language there are distinctive terms for maternal and paternal grandparents, so this wasn’t needed). Both sides of my family are from the Comilla district of Bengal, and that’s all I really cared about (and I didn’t care that much, I don’t put much stock in “heritage” as determinative).

As for other yields of personal genomics, I was skeptical. My parents have many siblings, and many, many, cousins. I had a general sense of my risks for diseases through an inspection of the pedigree of my family and their medical histories. Additionally, many of the risk alleles have been identified in European study populations, and I wasn’t totally sure about the between-population portability of these inferences. And I won’t even address the fact that effect size of many of the markers isn’t something to shout home about.

But last spring Daniel alerted me to the 23andMe “DNA Day” sale. It was affordable, and at that point enough of the readers of my weblog had been typed that I kept getting questions as to my own background (e.g., my family has the title Khan, so there was a question as to whether I carried the “Genghis Khan haplotype”). So I bit. At the time I recall emailing Dan and being excited that I’d be told I likely had brown eyes and was 75% “European” and 25% “Asian.” When my results came back, I was in for a mild surprise. The proportion to the left are calculated by 23andMe’s “ancestry painting” algorithm. As you can see, I’m more than 25% “Asian.” My initial reaction was that this seemed a touch high, but no worries, I would ask around and see which other South Asians had such a high value. After dozens of instances of “gene sharing,” the answer came back: none.
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Guest post: Barbara Prainsack on public attitudes to DTC genetic testing

Barbara Prainsack is senior author on a paper published last week exploring public attitudes to direct-to-consumer genetic testing. She kindly agreed to summarise the key findings of the paper for our readers.

Much has changed since the first personal genome testing (PGT) companies three launched years ago. Vivid discussions are taking place about the ethical and societal dimensions of especially the direct-to-consumer sector of PGT, and debates continue on how to regulate the field: Advisory commissions in many countries are issuing recommendations, and regulators have stepped in. In the meantime, Harvard’s Personal Genome Project (PGP) has reached over 1,000 participants, and PGT companies have dropped prices considerably and later raised them again. Of the three PGT companies (23andMe, deCODEme, Navigenics) which launched in autumn 2007, only one (23andMe) continues to sell their tests solely DTC (Navigenics offer their tests through doctors, and deCODEme do both), but numerous other companies have joined the DTC market. This shows that there is clearly an ongoing need for raising awareness and facilitating debates about personal genomics.

The launch of Genomes Unzipped (GNZ) last June, and to an even greater extent, the unzipping of the genome data of its core members, mark important steps on that road. One of the largest achievements of GNZ so far is that it has pushed the debate beyond hypothethical scenarios but enables a discussion of an actual scenario of real people publicly sharing their PGT results.

We hope that with findings from a survey published last week we can also make a small contribution to the debate. Early in 2008, our group at the Department of Twin Research and Genetic Epidemiology, and the Centre for Biomedicine & Society at King’s College London, started wondering what the potential market for such tests would be, for what reasons people would take the test, and what they would do with the results. In autumn 2008, we sent out questionnaires about PGT to 6,510 volunteers, aged 17-91, in the TwinsUK registry. 4,050 people responded to the survey, which to the best of our knowing makes ours the largest survey of public understandings of PGT so far.

Continue reading ‘Guest post: Barbara Prainsack on public attitudes to DTC genetic testing’


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