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.
Definition of a Single Nucleotide Polymorphism, SNP. A SNP is a site in the DNA where different chromosomes differ in the base they have. For example, 30 percent of the chromosomes may have an A, and 70 percent may have a G. These two forms, A and G, are called variants or alleles of that SNP.