Single nucleotide polymorphism

SNP or single nucleotide polymorphism is a sequence of DNA that varies with single nucleotide adenine (A), guanine (G), cytosine (C), and thymine (T). Within SNPs, a frequency is allocated, and the lowest frequency is observed at the locus. As there is a significant variation between humans' populations, it is possible SNP allele may be found rare in one group or another. 

A single nucleotide can be added, removed, or substituted in a polynucleotide sequence. SNPs may lie within intergenic regions, coding sequences of genes, and non-coding regions of genes. In both, the form an SNP leads to a polypeptide sequence called synonymous or known as a silent mutation. A different polypeptide sequence is generated, then it is known as nonsynonymous.  

A unique color and code are assigned to each Hapologroups in genetic technology. An SNP which is not tested yet or estimated is assigned a black color and + sign if tested confirmation and – if tested non-confirmation. A tested SNP is assigned with green color and (+) symbol. Sometimes it is also referred to as derived when quoted with green color. A tested SNP that is in red is not confirmed.  


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