Nukleotidpolymorphismus

Nukleotidpolymorphismus, often abbreviated as SNP (Single Nucleotide Polymorphism), refers to a variation at a single nucleotide position in a DNA sequence that occurs at a significant frequency within a population. This means that at a specific location in the genome, most individuals will have one type of nucleotide (like Adenine or Guanine), while a subset of the population will have a different nucleotide (like Cytosine or Thymine). SNPs are the most common type of genetic variation in humans, accounting for over 90% of all variations. They arise through spontaneous mutations during DNA replication or repair.

These variations can occur in coding regions of genes, potentially altering the amino acid sequence of a protein and thus affecting its function. Alternatively, SNPs can be found in non-coding regions, such as regulatory elements that control gene expression, or in intergenic regions with no known function. The presence or absence of a particular SNP, or a combination of SNPs (haplotypes), can be associated with differences in susceptibility to diseases, response to drugs, or physical traits. Therefore, SNPs are widely used in genetic research, including genome-wide association studies (GWAS), to identify genetic factors contributing to common diseases and to develop personalized medicine approaches.