Science medicine and the future: Postgenomic technologies: hunting the genes for common disorders

Abstract

The publication of a draft sequence of 90% of the human genome 1 2 heralds an exciting era in human genetics research. In the past 20 years, efforts have focused on mapping and cloning the genes for about 1000 human genetic disorders. This has led to the development of comprehensive services for prenatal diagnosis, carrier testing, and presymptomatic testing of mendelian disorders such as cystic fibrosis and the muscular dystrophies.3 Although this progress has been important to families affected by these diseases, it has had a limited effect on public health. All this could change if knowledge of 2.9 gigabases of the human genome sequence allows us to identify susceptibility genes for common diseases such as diabetes, asthma, and cancer. It may also lead to the identification of genetic variants that define a patient's response to a particular drug. If the promise of the genome sequence is even partially fulfilled, the next decade will see genetics spreading rapidly beyond the confines of specialist centres to impact on the diagnosis and management of common disorders in primary care. #### Summary points Genetic factors contribute substantially to the risk of developing many common diseases Susceptibility genes for common disorders are being sought by genome scans and association studies in large patient cohorts The publication of the sequence of the human genome and the discovery of millions of single nucleotide DNA polymorphisms have enhanced the prospects for identifying complex disease genes Knowledge of such genes would permit identification of individuals at risk of particular diseases, improved preventive medicine, and tailoring of treatment to specific genetic profiles and disease subtypes Single nucleotide polymorphism genotyping is likely to become part of the routine management of some common diseases within the next decade This article is based primarily on reviews in Nature , Nature Genetics , Science , …