Single-nucleotide polymorphism
= Single-nucleotide polymorphism
{wiki=Single-nucleotide_polymorphism}
Single-nucleotide polymorphism (SNP) is a variation at a single position in a DNA sequence among individuals. In other words, it's a change in a single nucleotide—the building blocks of DNA (adenine \[A\], cytosine \[C\], guanine \[G\], or thymine \[T\])—that can occur in the genome. SNPs can manifest in several ways, typically as a substitution of one nucleotide for another.