A SNP (Single
Nucleotide Polymorphism) is a single change of a unique nucleotide that can ocurr in the DNA sequence. To be considered a SNP, one of these variations has to take place in at least 1% of the population.
The SNPs cause the 90% of the human genomic variations and appear every 100-300 bases along the human genome.
As we already know, only a 1-2% of the genome encode for proteins so, the greatest part of the SNPs are located out of the coding region of DNA.
There are different databases where we can find SNPs of genomes from different species like, for instance, NCBI dbSNP or The SNP Consortium LTD .
Why are SNPs important?
We can find SNPs anywhere in the genome, and depending on where they are located they give us different kind of information.
SNPs found in the coding region of the genome:
They are of great interest because they can alter the biological functions of the proteins.
SNPs found in the noncoding region of the genome:
Studying the fragments of DNA with SNPs related with a trait disease will let us know which is the role of the genetic factors of the disease and evalue the importance of the non-genetic ones. Moreover, it will also let us study the interpersonal differences according, for instance, to the treatment response or the secondary effects that affect some people.
For these reasons, SNPs suppose a revolution in the medical area for the detection and prevention of diseases.
But SNPs are not only important for those reasons. When studying the evolution of species and the history of human populations, these polymorphisms are very useful to check diversity.
Comparing SNPs in genomes from different species we can understand which are the changes that have ocurred along the evolution and predict the ancestral state, it means, to determine the original SNP from which mutations have taken place.
The goal of our project is to create a program that shows us the SNP surrounded by the sequence upstream and downstream by introducing up to 90 identification numbers (rs) of the human genome.
We think that this program will be of great interest because it will let us do further studies, like compare those sequences with genomes from other species and try to locate the corresponding SNP.
With this information we will be able to find which is the ancestral state if a nucleotide change has ocurred.
