NCI Dictionary of Genetics Terms
Welcome to the NCI Dictionary of Genetics Terms, which contains technical definitions for more than 150 terms related to genetics. These definitions were developed by the PDQ® Cancer Genetics Editorial Board to support the evidence-based, peer-reviewed PDQ cancer genetics information summaries.
- A single nucleotide polymorphism, or SNP, that is used to “tag” a particular haplotype in a region of the genome. As a subset of all of the SNPs in the genome, tagSNPs can be extremely useful for testing the association of a marker locus with a qualitative or quantitative trait locus in that it may not be necessary to genotype all of the SNPs. Also called tagging SNP.