Last night’s CPC featured a topic suggested by Louise Gillies, ‘Who owns my genetic information?’ Chris Groves introduced the session with a short talk covering the nature of genomics, together with some of the ethical issues raised by the nature of genomic information and the technologies which may help us exploit it. The genetic code, consisting of molecules of DNA each formed of some 3 billion base pairs of 4 kinds of nucleic acids, is found in the chromosomes within each cell of a living creature. Around 0.2% of these base pairs are ‘coding’ DNA, which influence how cells make proteins and thus reproduce themselves and thereby the bodies and characteristics (the ‘phenotype’) of living things. The rest is ‘non-coding’ DNA, which was once thought to be functionless (‘junk’) but is now thought to have other regulatory functions within cells. Thanks to its functions in shaping individual development, DNA is often described metaphorically as a ‘blueprint’ or ‘recipe’ for making individual living creatures.
In humans, the advent of sequencing technologies and powerful computers in the 1990s made possible for the first time a complete sequencing of the human genome as part of the Human Genome Project, a ‘map’ of the base pairs that make up human genetic material. Among the hopes expressed for how genomic science could change the world, many geneticists and clinicians spoke of a new era of preventative medicine, based on population studies that would yield knowledge of the links between genetic variants (‘genotypes’) and medical conditions (‘disease phenotypes’). Clinical genetic tests had been around for a while for single-gene conditions (like Huntingdon’s disease) and also for ‘high-penetrance’ genes that were strongly associated with particular conditions (as in the case of the links between the BRCA1/2 genes and breast cancer, for example). But the capability of fully sequencing individual genotypes (or, alternatively – and less expensively – looking for single nucleotide polymorphisms [SNPs] in regions of the genome known to be significant for particular diseases) meant that genomic components for common conditions (such as diabetes or heart disease) involving perhaps thousands of genes could also be identified.