Single nucleotide polymorphism or 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.
In SNPedia, you can learn how these variations in your DNA may trigger diseases as the wiki focuses on the SNPs which are believed to influence your health. There is a fantastic amount of data and you can browse by genes or even medical conditions. The to-do list is really scary.
Anyway, why is it an important and clever idea?
We believe that if we can identify more and more SNPs and we can find out how these variations trigger diseases, then we just constructed the basics of personalized genetics. Imagine a world where you just have your genome sequenced, and after identifying your SNPs (I mean at least all the most popular ones), they can tell you what kind of diseases you have elevated risk for. Isn’t it futuristic? Actually, it should be reality in about 5 years or am I too optimistic again?