It has been defined as 'the use of genomic information and technologies to determine disease risk and predisposition, diagnosis and prognosis, and the selection and prioritisation of therapeutic options' ( House of Lords Report, 2009).
New technologies are providing:
Genomic information informs diagnosis and therapy.
Automated DNA sequencing can detect sequence variations in the genome in inherited diseases, whilst DNA microarrays can investigate the presence or absence of copy number variation in malformation syndromes, and the expression of genes in conditions such as cancer. The technologies have led to new and more precise molecular classifications of some disease states which can lead to targeted treatment strategies.
Professor Sian Ellard Peninsula Clinical Genetics Service
As well as helping families with inherited diseases, the new technologies have been useful in identifying genetic components of common diseases. Genome-wide association studies (GWAS) compare genetic variants in very large populations of people with a particular disease with those who do not have the condition. Genetic variants found at an increased frequency in people with a particular condition compared with people without the condition are said to be "associated" with the condition. Further studies are undertaken in the area of the genome containing the variant to find genes that may increase susceptibility or give protection to the condition.
For example, in June 2007, the Wellcome Trust Case Control Consortium reported the localisation of 24 new susceptibility loci using the GWAS approach and studying half a million genetic variants in 17,000 people. The conditions were bipolar disorder, coronary artery disease, Crohn's disease, rheumatoid arthritis, and types 1 and 2 diabetes.
By March 2010, 779 areas of the genome implicated in 148 common diseases and traits had been identified in the published literature. Much of this information requires further assessment before its place in clinical management is justified, but there are examples where genomic information has made a real difference to patient care.
Molecular diagnostic tests have led to an improved ability to stratify common diseases, predict risk of future disease and target the use of drugs.
Stratified medicine allows patients to be placed into discrete groups with a view to optimising prevention or treatment of a disease. Personalised Medicine takes this one step further by including a wider spectrum of factors, specific to the individual patient, such as other drugs being taken, the presence of other diseases, and the patient's personal preferences about treatment, so that prevention strategies or treatment can be optimised at a personal level.
Stratified Medicine and Personalised Medicine have always been central to the practice of medicine. What has changed over recent years is the precision with which stratification and personalisation can be done with the improved understanding of the molecular and genetic bases of disease.
Other exciting potential applications of genomic medicine undergoing clinical validation include:
The NHS National Genetics Education and Development Centre has played a key role in developing learning outcomes and resources for genetics teaching and learning. We are currently reviewing learning outcomes and consulting on their amendment to incorporate advances in genomic medicine. Through educational needs assessments, our aim is to identify what is required to increase support for educators and learners in genomic medicine. If you are interested in joining the debate, please contact us for further information.
Last updated: 18 October 2010
