: a variant DNA sequence in which the purine or pyrimidine base (such as cytosine) of a single nucleotide has been replaced by another such base (such as thymine)
Cite this Entry
“SNP.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/SNP. Accessed 10 Sep. 2025.
Copy CitationMedical Definition
SNP
noun
: a variant DNA sequence in which the purine or pyrimidine base (as cytosine) of a single nucleotide has been replaced by another such base (as thymine)
Most SNPs occur in places in the genome that aren't used for making proteins—the so-called junk DNA. But the few SNPs that land squarely in a gene or in a regulatory region near a gene can alter characteristics influenced by that gene …—
Christen Brownlee, Science News
Christen Brownlee, Science NewsThe ultimate goal of the pharmaceutical industry is to find the SNPs involved with major diseases and use them to find specific molecular targets for drugs.—Tim Friend, USA Today
Tim Friend, USA Todaycalled also single nucleotide polymorphism
Love words? Need even more definitions?
Merriam-Webster unabridged
Share