A human genome in minutes, and what it will mean to you

Based on a presentation by: Hagan Bayley (Prof of Chemical Biology, University of Oxford) – 22/01/13

I attended an excellent seminar last week, which forms part of the University of Liverpool’s ‘Science and Society 2013’ series. The whole series is intended to educate scientists and non-scientists alike about how science can benefit wider society. What better way to kick off my blog than with a summary of the key points of a talk aimed at exploring the very relationship I want to address?

So, first thing’s first – what is a genome? Well, everyone knows that a gene is a piece of DNA that fulfils some kind of function, like encoding a protein. If you imagine that a gene is a word in a sentence, then a genome is one massive sentence made up of those words. In addition, as with all good sentences, the words are separated by spaces. In a genome these are regions of DNA that don’t actually have a function – these spaces can be long, as if someone fell asleep                  on the keyboard! Every ‘character’ in a genome is one of 4 molecules called ‘bases, and it’s the endless number of combinations of these characters that gives us the variety of life we see in the world.

The human genome is 6 billion bases long – as Prof Bayley brilliantly put it, that’s roughly 1,000 copies of War and Peace’ – in other words, it’s long! In spite of this, it’s been sequenced from start to finish; that is, every character in the sentence has been read. Even more impressive than that is the speed at which technology is letting our reading abilities improve. The first human genome took 13 years and $3 billion to sequence before its completion in 2003. Yet, by 2007 the cost had fallen to $70 million. Today, it takes less than $10,000 and 11 days! But where can we go from here?

Well, a company called Oxford Nanopore Technologies has designed a new way of reading a genome. Small pieces of DNA are passed through a microscopic pore on a computer chip. An electrical current is passed across this ‘nanopore’ and, as the DNA passes through, its bases disrupt the current. The 4 bases affect it in different ways, meaning they can be identified by the disruption caused. This fascinating approach to sequencing is incredibly fast, capable of sequencing a human genome in under 2 hours!

So, how will all of this affect us, and should we be happy or wary of these advances? Well, whilst the potential benefits are incredible, the ethical issues that rear their ugly heads are rather numerous:

Medicinal fields are key areas to watch out for – if doctors could read your individual genome they might know how likely a drug treatment would be to work for you. This application could save time, money and, potentially, lives. However, what if someone could tell you that you were likely to develop Alzheimer’s Disease – would you want to know? Moreover, would you want your employer or insurance company to know? Such knowledge could cause huge disruptions to your life. Depending on the news, it could ruin it.

The field of forensic science often revolves around genetic information, as DNA left at a crime scene can be enough to convict a criminal. Being able to sequence a suspect’s genome more quickly and accurately would undoubtedly aid criminal investigations. However, in the UK, the genetic data obtained for suspects in a crime, not just the convicted, remain on a national database, with samples currently numbering at 5 million. As the availability of sequenced genomes grows, who should be kept on such a database? And for how long? Is it even ethical to sequence someone’s genome without their knowledge? In the UK it’s illegal unless it’s part of a medical or criminal investigation but this may not always remain the same.

As you can see from this, admittedly brief, look at some of its implications, it’s not going to be enough just to revel in the glory of faster sequencing. As a worldwide society, we’re going to need to decide how it can be used and how it should be managed. For my money, I think the sequencing technology is fascinating and will improve scientific research no end, which, in turn, will have benefits on the wider society. However, as something of a worrier in life in general, I hate the idea of knowing years in advance what diseases and conditions I’m likely to develop. That’s one application I wouldn’t lament never seeing the light of day. That said, only time will tell how it will play out and this science is most definitely going to affect society in one way or another.

If you’re in the Liverpool area and this has piqued your interest, I strongly suggest booking a place for some of the other talks in the ‘Science and Society 2013’ series:

http://www.liv.ac.uk/events/science-and-society/