Single Nucleotide Variant

A single nucleotide variant (SNV) is a small change in the DNA sequence where one building block, called a nucleotide, is different from what is usually found. Think of DNA as a long string of alphabet letters; an SNV is like swapping out one letter for another at a specific position. These tiny changes can affect how genes work and may influence traits or disease risk. SNVs are common in all humans and contribute to genetic diversity. Most have no effect, but some can have important biological or medical implications.