The birth and death of human single-nucleotide polymorphisms: new experimental evidence and implications for human history and medicine.

Extensive, new databases of single-nucleotide polymorphisms (SNPs) provide a powerful resource for disease gene discovery, and they will be even more useful as more frequency data become available. Interesting observed genomic patterns include SNP deserts (regions of low SNP incidence) and lengthy regions of linkage disequilibrium containing only a few haplotypes. A variety of genetic studies will benefit from SNP resources.