Microarrays and macroconsequences

The National Human Genome Research Institute of the National Institutes of Health is delighted to sponsor this special supplement of Nature Genetics . Within these pages the reader will find a series of state–of–the–art reviews of the technology for production of nucleic acid microarrays in various formats. Examples of their utilization to address interesting biological problems are provided, as is a consideration of the challenging informatics problems presented by the collection of a great deal of data in a short period of time.

As the Human Genome Project hurtles towards completion of the first finished human sequence (now scheduled for 2003), microarray technology offers the potential to open wide new windows into the study of genome complexity. Applied to expression analysis, this approach facilitates the measurement of RNA levels for the complete set of transcripts of an organism. Applied to genotyping, microarrays usher in the possibility of determining alleles at hundreds of thousands of loci from hundreds of DNA samples, allowing the contemplation of whole genome association studies to determine the genetic contribution to complex polygenic disorders. Applied to mutation screening of disease genes with pronounced allelic heterogeneity, the use of microarrays is likely to move the possibility of genetic testing for disease susceptibility of individuals, or even entire populations, into the realm of practical reality.