Just as I was sitting down, deciding what to write this post on, someone asked me on twitter "What are SNPs"?
Every profession and area of study has a bunch of acronyms and field specific terms that can be very confusing to those outside the field. Genetics is no different and SNP is one of our worst.
SNP stands for Single Nucletide Polymorphism.
No clearer, huh?
Okay, lets start at the end. Polymorphisms are when there is more that one version of a gene in the population - think eye colour and have a look at my post here.
When we talk about Single Nucleotide Polymophisms it means that at one specific position in the genome, some individuals will have one nucleotide and some individuals will have a different nucleotide.
There are a huge number of positions where this occurs and they're all categorised in a database. Many of the differences have no apparent function, others cause changes but neither option is better than the others. Other rare SNPs may be involved in genetic diseases.
SNPs are very useful in genetics for a number of reasons. One of the big uses in is Genome Wide Association Studies, which allow us to find regions of the genome which are associated with certain traits or diseases. The SNPs themselves may not actually be involved, but nearby regions maybe. We'll talk more about this when I get onto recombination.
Another reason why it's important to know about SNPs is in looking for the genetic mutation causing someone's disease. When their gene is sequenced and compared to the human reference genome, a number of different mutations may come up. It's important to be able to rule out the ones that we know are common and are therefore unlikely to be causing the disease.
So that's it, SNPs demystified. They're just single nucleotide substitutions, we just gave them a complicated name.
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