Potential of genetic translational research in gastroenterology.

The concept that genetic variation underlies inter-individual differences in drug response and contributes to the risk of developing common, complex disorders is expanding rapidly. Consequently the interest in genetic translational research has increased. Polymorphic DNA markers, either microsatellites or single nucleotide polymorphisms (SNPs), are used to assess genetic identities and track genetic differences between individuals. Given their abundance and stability, SNPs hold great promise as markers for mapping disease susceptibility loci for common, complex disorders by association studies. For this purpose the development of inexpensive, accurate, high-throughput methods for scoring large numbers of SNPs from hundreds of patients and controls is critical. Furthermore, gene expression profiling using DNA microarrays is likely to become a useful diagnostic tool enabling classification of disease phenotype based on molecular basis of disease pathogenesis, revealing information that cannot be obtained by histological assessment. Moreover, identification of differentially expressed genes in affected versus control tissue or over time in affected tissue will lead to better understanding of the mechanisms underlying disease and ultimately to the development of more effective drug therapies. To illustrate the potential of genetic translational research, several examples in the field of gastroenterology are described.