News tagged with single nucleotide polymorphisms

Related topics: genetic variation

Mechanism affecting risk of prostate cancer is found

A research group at Biocenter Oulu in Finland has identified a mechanism related to a transcription factor that binds much more strongly onto a particular SNP variant, thereby initiating a genetic programme which enhances ...

Jan 10, 2014
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Family history doubles aortic stenosis risk

The risk of aortic stenosis doubles when a first degree relative had the disease, according to research presented at ESC Congress 2013 today by Dr. Mattis F. Ranthe from Denmark. The study of 4.2 million people from Danish ...

Sep 01, 2013
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Single-nucleotide polymorphism

A single-nucleotide polymorphism (SNP, pronounced snip) is a DNA sequence variation occurring when a single nucleotide — A, T, C, or G — in the genome (or other shared sequence) differs between members of a species (or between paired chromosomes in an individual). For example, two sequenced DNA fragments from different individuals, AAGCCTA to AAGCTTA, contain a difference in a single nucleotide. In this case we say that there are two alleles : C and T. Almost all common SNPs have only two alleles.

Within a population, SNPs can be assigned a minor allele frequency — the lowest allele frequency at a locus that is observed in a particular population. This is simply the lesser of the two allele frequencies for single-nucleotide polymorphisms[1]. There are variations between human populations, so a SNP allele that is common in one geographical or ethnic group may be much rarer in another.

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