What are Single Nucleotide Polymorphisms?

Genetics has a vital role to play in developing diagnostic tools and treatments for diseases and genetic disorders. Biomedical researchers are now busy deciphering human genomes, variation in genetic codes, and the coding sequences responsible for human diseases. Many strides have been made and SNPs could soon usher in a revolution in personalized medicine.

In human genome analysis, scientists have found that 99 per cent of individuals have identical DNA sequences. However, they have found a small genetic variation in every person’s DNA. These subtle differences occur when just one nucleotide is altered and the term used is single nucleotide polymorphism (SNP). An example of an SNP is in the alteration of the following DNA sequence: ATTGGCT to AATGGCT - where the second T in the first sequence is replaced with A in the latter sequence.

DNA contains regions known as exons and introns. The former codes for proteins and the latter does not. Most of the SNPs fall in the non-coding region. However, SNPs that are present in the coding region are of great interest to researchers, as they can alter the function of proteins. Biomedical researchers have developed advanced tools to find single nucleotide changes in the human genome.

Most SNPs do not cause disease. They are useful to researchers as a biological marker for analyzing a particular disease. It has been found that these SNPs are present near genes associated with certain diseases. They also determine how humans respond to disease and environmental assaults such as bacteria and viruses. It's this aspect that is giving scientists the hope that one day personalized medicines (rather than the catch-all generic drugs we have today) can be designed; tailored to an individual's own genetic make up.

Genetic studies will also answer questions as to why individuals differ in their abilities to absorb drugs and why an individual may experience adverse side effects to a particular therapeutic. In this context, the recent discovery of SNPs promises to revolutionize not only the process of disease detection, but the practice of preventive and curative medicine as well.

Ncbi. “SNPs: Variations on a Theme.” Retrieved on December 7, 2008 from SNPs: Variations on a Theme.