[Analysis of single nucleotide polymorphisms (SNPs)].

Single nucleotide polymorphisms (SNPs) are DNA sequence variations occurring when a single nucleotide in the genome differs in paired chromosomes. Some SNPs in the coding region change the amino acid sequence of a protein, and others in the coding region do not affect the protein sequence. SNPs outside the coding region may also affect transcription factor binding, gene splicing, or mRNA degradation. With or without such impacts on the biological function of gene products, SNPs are strongly useful as markers to examine linkage disequilibrium and to explore genetic polymorphisms in the research of population genetics and medical science. Knowledge about SNPs is expected to help in identifying susceptibility genes for complex diseases, drug susceptibility genes, and histocompatibility genes for transfusion or transplantation. Recent breakthroughs in DNA technology, such as high-throughput universal SNP microarrays and next-generation sequencers, have made it possible to carry out comprehensive analyses of DNA at the whole genome level, resulting in the implementation of a genome-wide association study(GWAS). In GWAS, SNPs are used as high-solution markers in gene mapping related to diseases versus normal traits. The outcomes of GWAS provide a number of supportive findings for the promotion of personalized medicine based on genome informatics. This article presents a review of SNP analysis with respect to its scientific significance and current progress.