The cost of DNA sequencing has been falling rapidly ever since genetics pioneer Craig Venter famously decoded his own genome back in 2007 – at an estimated cost of $10m. Today’s technologies work mainly by tagging the sequence of DNA bases – A, G, C and T – with fluorescent markers and recording the various colours passing along a single DNA strand. But alternatives to these optical technologies promise to bring costs down well below the much targeted $1000 per genome. In the journal Nature Biotechnology (doi:10.1038/nbt.2147), for example, researchers this week report a step towards a ‘next generation’ sequencing technology achieved through the use of an enzyme to control the movement of DNA through nanopores in an artificial membrane. 

Sequencing with nanopores, the researchers say, has the potential of rapidly reading long strands of DNA without the need for amplification by PCR (polymerase chain reaction), chemical labelling or optical instrumentation – a capability that will surely put genome sequencing more on track towards mainstream commercialisation.

The appetite for knowing about our personal genetic make-up cannot be underestimated. There are companies aplenty already making good money for services involving scanning the genome for common genetic variants – single nucleotide polymorphisms (SNPs) – with tests available for less than $100 that purport to inform both of a predisposition to certain diseases along with information pertaining to individual DNA ancestry. Full genome sequencing will not only be much more accurate and reliable, but it should also provide us with much deeper insights into the nature of inherited diseases, the peculiar characteristics that comprise our individual phenotype and even, ultimately, about our own individual personality traits and behaviours that make us who we are.

Exactly how revealing such technologies can be, however, remains an important philosophical and even, fundamentally perhaps, a religious question. Are we all merely the products of the genes and chemicals that they encode? Or is there more to understand than simply reading off patterns of biochemical signals? As science continues to make progress, the biochemical argument would appear to be gaining ground. Even the old nature versus nurture debate, after all, would now appear to have a scientific basis, with the switching on and off of genes by environmental cues determined at least in part by epigenetics. So would I have my own genome sequenced? Definitely not. Some things in life are better to remain a mystery.

Cath O’Driscoll – Deputy editor