I have recently been thinking about discovering more of my ‘inner self’, specifically, the digital representation of me: my genome. I am genetically curious and keen to explore the potential of personal genomics and the issues surrounding it. Investigating my own DNA seems to be a good way to do it.
After some preliminary research, I’ve discovered that there are a number of things to consider before I go ahead. Whole genome sequencing is not cheap, though it is getting cheaper. Do I want to let a company have my genetic information? Will this affect my insurance? The UK does not have a legal equivalent to the partial protection that the American GINA (Genetic Information Nondiscrimination Act) law provides. Do I want to know if I carry certain disease susceptibility genes? How useful is it to know my genome sequence?
The 3 billion letters of DNA code that comprise the human genome is the blueprint for all of an individual’s hereditary information. This unique code is packaged into 23 pairs of chromosomes; one from each pair is inherited from each parent whose DNA is a mosaic of their ancestors. Our genome is a digital representation of our past, ourselves and arguably an indicator of our future.
The first person to have their genome sequenced and subsequently published was Craig Venter, the American entrepreneur and research scientist, in 2007. Venter’s genome sequence and the methods used to decode it were described in detail in the open access journal PloS One, and the full sequence was deposited into the public database, Genbank.
Shortly after, the genome sequences of James Watson and a small number of other individuals were added to the database. This was the culmination of a decade long process, riddled with scientific and political controversy, infighting and argument. Surely, after all that, knowing something about your DNA must be worth it.
The $1000 genome
Steve Jobs reportedly paid $100,000 to discover his sequence. A number of other wealthy individuals followed suit, including Sergey Brin, one of the founders of Google. In the years since, the cost of sequencing a human genome has plummeted, obliterating Moore’s law (see graph). Last month, Illumina and Life Technologies announced two new systems that could sequence a human genome in a day for the bargain price of $1000. Soon you will be able to have your genome sequenced for the price of a decent laptop.
With the sequencing process becoming cheaper, several personal genomics companies have been springing up offering to decode people. At present, the majority of these commercial outfits provide their customers with a reduced version of their genome, their SNPs (pronounced ‘snips’), in exchange for a small volume of their spit in a tube. These SNPs (single-nucleotide polymorphisms) are variations that occur in the DNA code when one letter in the sequence differs between people or chromosomes. It has been estimated that there are ~10 million SNPs in the genome; they are thought to affect how people develop diseases and respond to pathogens, drugs and vaccines and they can also be used as biological markers. A company will probe your DNA for a selected set of SNPs, then let you know which ones you have. Some companies might even tell you what diseases, traits or ancestry some SNPs are linked to.
Looking into the crystal ball?
So what do you do with all of these letters and SNPs once you’ve downloaded them? What do they mean? Can you predict your future? Well, not really. Knowing that you have a certain SNP or gene that has been linked to Alzheimer’s does not necessarily mean that you are going to develop the disease; it is merely associated with an increased risk of doing so. In addition, our understanding of disease pathways and mechanisms are still limited, it may be that the effects of one gene are counteracted by another. The development of a disease is often due to a large network of genes working together, not a single rogue gene.
Despite this, I admit I’m still curious to know both my genome sequence and what SNP versions I have. I would always rather know something about my genome than not know, equally I respect that many people will not want to know their genetic information.
The real value of genomic data is not in knowing the sequence of one individual, but of many. In order to exploit the full potential of genomics we need to sequence millions of genomes to enable comparison studies that show distinctions between groups with a certain disease and those without. A report in Nature last week revealed that Norway is to be the first country to incorporate genome sequencing into its national healthcare system. Will Britain and other countries do this anytime in the near future? Will people be willing to include their genomic information in a study? This of course raises privacy and data protection issues, I’ll attempt to address this in a future post.
Data science will dominate
An increasing number of genome sequences will result in the production of huge volumes of data. This will need to be analysed, interpreted and explained both at the individual and population level. In order to keep up with this tidal wave of data, more people with skills in bioinfomatics and programming will be required, in addition to people who can explain this data to patients and individuals. Perhaps this will result in more international genomic collaborations as more and more sequences become available. How will we manage all of this information? How will it be regulated?
Thinking about investigating my own genome has raised a number of issues that I have to explore before I decide to go ahead. I’ve added a quick two question poll below, feel free to add your opinions!
Let the personal decoding begin….
More to come…