A summary of the new standards follows this preface. The summary and the one-. page chart in Appendix C describe the classes of nonexchange transactions and give an. overview of the recognition criteria for each class.
What are single nucleotide polymorphisms (SNPs)? Single nucleotide polymorphisms, frequently called SNPs (pronounced âsnipsâ), are the most common type of genetic variation among people. Each SNP represents a difference in a single DNA building block, called a nucleotide. For example, a SNP may replace the nucleotide cytosine (C) with the nucleotide thymine (T) in a certain stretch of DNA. SNPs occur normally throughout a personâs DNA.
If a SNP occurs within a gene, then the gene is described as having more than one allele. In these cases, SNPs may lead to variations in the amino acid sequence. SNPs, however, are not just associated with genes; they can also occur in noncoding regions of DNA.Although a particular SNP may not cause a disorder, some SNPs are associated with certain diseases.These associations allow scientists to look for SNPs in order to evaluate an individual's genetic predisposition to develop a disease.n these cases, SNPs may lead to variations in the amino acid sequence. SNPs, however, are not just associated with genes; they can also occur in noncoding regions of DNA. Although a particular SNP may not cause a disorder, some SNPs are associated with certain diseases.