Single Nucleotide Polymorphisms (SNPs) are variations that occur at a single nucleotide base within the DNA sequence of an organism. SNPs are considered the most common and smallest form of genetic variation found in the genomes of individuals from the same species.
Each SNP arises due to a single DNA base substitution, where one nucleotide (adenine [A], thymine [T], cytosine [C], or guanine [G]) is replaced by another. The substitution may occur with different frequencies in the population, resulting in two or more forms of the SNP, known as alleles. For example, at a given SNP locus, one individual may have an A nucleotide, while another individual may have a T nucleotide.
SNPs are scattered throughout the genome and can have different effects on gene function or protein structure. Some SNPs are silent, meaning they do not cause any change in the amino acid sequence of a protein. However, others can result in amino acid substitutions, potentially affecting protein function or altering gene expression levels.
SNPs are important genetic markers in genetic studies and are utilized in various applications such as disease association studies, genetic ancestry determination, and personalized medicine. By examining the presence or absence of specific SNPs in an individual's genome, researchers can gain insight into genetic predisposition to diseases or identify population-specific genetic variations. SNPs are often assayed using high-throughput genotyping technologies, allowing for the efficient analysis of large numbers of SNPs across samples.
