Single Nucleotide Polymorphism

What is SNPs?
Single nucleotide polymorphisms or SNPs (pronounced "snips") are DNA sequence variations that occur when a single nucleotide (A,T,C,or G) in the genome sequence is altered. For a variation to be considered a SNP, it must occur in at least 1% of the population. SNPs, which make up about 90% of all human genetic variation, occur every 100 to 300 bases along the 3-billion-base human genome. Two of every three SNPs involve the replacement of cytosine (C) with thymine (T). SNPs can occur in both coding (gene) and noncoding regions of the genome. Many SNPs have no effect on cell function, but scientists believe others could predispose people to disease or influence their response to a drug.


The International HapMap Project
The International HapMap Project is a multi-country effort to identify and catalog genetic similarities and differences in human beings. Using the information in the HapMap, researchers will be able to find genes that affect health, disease, and individual responses to medications and environmental factors. The Project is a collaboration among scientists and funding agencies from Japan, the United Kingdom, Canada, China, Nigeria, and the United States.

The goal of the International HapMap Project is to compare the genetic sequences of different individuals to identify chromosomal regions where genetic variants are shared. By making this information freely available, the Project will help biomedical researchers find genes involved in disease and responses to therapeutic drugs.

For more information about the HapMap Project, visit http://www.hapmap.org/thehapmap.html.en and http://www.hapmap.org/whatishapmap.html


Latest Deveplopment In The International HapMap Project
On October 27th at the American Society of Human Genetics 2005 Annual Meeting, the Wellcome Trust, the National Institutes of Health and the National Human Genome Research Institute offered a two-hour tutorial on effective HapMap usage. The session included an introduction to the HapMap, use of the HapMap for association studies, tag SNP selection, improving analyses using chips with pre-selected SNPs and a guide to the HapMap Web pages.

For more information, visit http://www.genome.gov/17015048


My Thoughts
After reading the about the International Hap Map Project, I'm impressed by the efforts that the scientists from around the world put in to identify the genetic variants that occur in human beings, which differentiates the appearance of human beings, the likelihood of suffering from disease, as well as the responses to substances that we encounter everyday in our life.