What are single nucleotide polymorphisms (SNPs)?

Single nucleotide polymorphisms, commonly referred to as SNPs, are variations at a single nucleotide position in the genome. This means that at a specific location in the DNA sequence, there are two or more variations that occur among individuals in a population. These small changes can have significant implications for genetic diversity, evolution, and individual susceptibility to diseases.

SNPs can influence how humans respond to drugs, susceptibility to environmental factors, and risk of developing certain diseases. They are the most common type of genetic variation among people and are used in a variety of genetic studies, including genome-wide association studies (GWAS) that search for connections between specific genetic variants and diseases.

This definition distinguishes SNPs from other genetic phenomena such as mutations that affect entire genes or duplications of genes, both of which involve larger segments of DNA rather than individual nucleotides. Additionally, SNPs are not proteins; they are specific locations in the DNA that may lead to different forms of a gene or trait but are fundamentally alterations in the DNA sequence itself.