Changes

<p>한개의 염기서열의 차이를 이용하는 것을 말한다.&nbsp;<br /><br />1번&nbsp;개체 AC<strong>C</strong>ATG<br />2번&nbsp;개체&nbsp;AC<strong>T</strong>ATG&nbsp;<br /><br />두&nbsp;개체간의 염기서열의 차이를 이용하게 된다.<br />예를 들어 특정 질병에&nbsp;잘 걸리는 집단과 잘 걸리지 않은 집단간의 유전자 차이를 비교, 질병의 원인을 규명혹은 마커 발견 할&nbsp;때 유용하게 쓰이게 된다.&nbsp;&nbsp;<br /><br /><font size="3"><strong>[Definition]</strong><br />SNPs are single base pair positions in genomic DNA at which different <br />sequence alternatives (alleles) exist in normal individuals in some <br />population(s), wherein the least frequent allele has an abundance <br />of 1% or greater. &nbsp;<br /></font></p><p><font size="3"><strong>[Narrow scope]</strong> <br />Single base insertion/deletion variants (indels) would not <br />formally be considered to be SNPs. &nbsp;<br /></font></p><p><font size="3"><strong>[Pronunciation]</strong><br />SNP (pronounced 'S' 'N' 'P' or 'SNiP') &nbsp;<br /></font></p><p><font size="3"><strong>[Characteristics of human SNPs]<br /></strong>Understand human DNA polymorphism, about 90% of which is <br />single nucleotide polymorphism (SNP) &nbsp;<br /></font></p><p><font size="3">SNPs could be bi-, tri-, or tetra-allelic polymorphisms. <br />However, in humans, tri-allelic and tetra-allelic SNPs are rare almost <br />to the point of non-existence, and so SNPs are sometimes simply <br />referred to as bi-allelic markers (or di-allelic) &nbsp;<br /></font></p><p><font size="3">The typical frequency with which one observes single base differences in genomic <br />DNA from two equivalent chromosomes is of the order of 1/1000&nbsp;bp = 0.1% &nbsp;<br /></font></p><p><font size="3">cf) non-coding HLA regions show nucleotide diversity levels of 5&ndash;10%&nbsp;<br /><br /><br /></font><font size="3"><strong>[Application]<br /></strong><br /><strong><em>Population genetics and linkage disequilibrium</em> :</strong><br />The study of the genetic composition and inter-relationships between <br />populations. The major research tool it uses is DNA polymorphism.&nbsp;&nbsp;&nbsp; <br /></font></p><p><font size="3"><em><strong>Complex phenotypes and genome variation :</strong><br /></em>Risks of major common diseases such as cancer, cardiovascular disease, <br />mental illness, auto-immune states, and diabetes, are expected to be heavily<br />influenced by the patterns of SNPs one possesses in certain key susceptibility <br />genes yet to be identified. &nbsp;<br /></font></p><p><font size="3"><em><strong>SNP based association studies :</strong></em><br />If a factor contributes an increased risk for disease occurrence, then that factor <br />should be found at higher frequency in individuals with that disease compared to <br />non-diseased controls </font></p>