The SNP initiative at NIH began in 1998. A SNP, short for single nucleotide polymorphism, is a difference in a single chemical subunit of DNA - in other words, a single base of DNA sequence that varies among people. SNPs can be used as the markers on a genetic map. The single letter spelling differences can be detected by PCR (polymerase chain reaction). Previous genetic mapping efforts, with microsatellites as the markers, have been helpful in the search for genes where a single mutation can cause a disease - like cystic fibrosis and Huntington's disease. But many common diseases, like diabetes, heart disease, and psychiatric disorders, have been more difficult to study because they result from the effects of multiple genes. SNPs will be an important tool for mapping these and other "multi-gene" disorders.
Collins F.S., Brooks L.D., Chakravarti, A. A DNA polymorphism discovery resource for research on human genetic variation. Genome Res, 8: 1229-31. 1998. [Full Text]
Last Reviewed: May 28, 2013