The human genome comprises some 20,000 genes, or 3 billion base pairs. Variation in this genetic sequence is common and some of these variants affect gene function or the protein transcribed from it. Human characteristics are determined by the interaction of the genome with environmental challenges, and differences between us thus result from variation in those challenges and in the genome itself. This is true of human susceptibility to disease, and survival from it. Genetic variation influences human behaviours which may predispose to health or disease; the risk of contracting an infectious disease, or of suffering diseases such as cancer or myocardial infarction; the development of complications; the response to any treatment administered; and thus the outcome of the disease state. Genetic studies can help shed light on the mechanisms which underpin disease processes, whilst perhaps suggesting ways in which treatment might be ‘personalised’, and novel therapeutic targets for drug development.
More sophisticated approaches to such endeavours are required, given the failure to identify the bulk of gene variants of influence using conventional strategies.
Key words: gene, polymorphism, survival, genome