What are SNPs? SNPs are single-nucleotide substitutions of one base for another

1. What are SNPs? • SNPs are single-nucleotide substitutions of one base for another • Each SNP location in the genome can have up to four versions: one for each nucleotide, A, C, G and T. • A SNP and its distribution in a population might look like this:

2. Not all single-nucleotide changes are SNPs • To be classified as a SNP two or more versions of a sequence must each be present in at least one percent of the general population • SNPs occur throughout the human genome - about one in every 300 nucleotide base pairs which means about 10 million SNPs within the 3-billion-nucleotide human genome

3. SNPs are NOT The Same As Disease Causing Mutations • Both are single-nucleotide differences in a DNA sequence - but SNPs should not be confused with disease-causing mutations • Some tell-tale differences are: • 1. SNP must be present in at least one percent of the general population - no known disease-causing mutation is this common • 2. most disease-causing mutations occur within a gene's coding or regulatory regions - SNPs are not necessarily located within genes and they do not always affect protein function

4. SNPs are divided into two main categories:

5. Personalized Medicine • Individuals with the same disease respond differently to drug treatment – differences in gene expression mostly due to SNPs • Pharmacogenetics first emerged around the 1950s - scientists began to notice that different responses to drugs ran in families and ethnic groups • Pharmacogenetics aims to figure out how people's genetic variations correlate with their responses to a specific medication

6. SNP Analysis and Pharmacogenetics Activity Pharmacogenomics: Drugs Designed For You module can be found at: http://gslc.genetics.utah.edu/teachers/tindex/ Pages 2 and 3 of Teacher Guide gives ideas for classroom implementation, extensions, adaptations, and assessments Students get S1-4

7. Adaptation • Include Microarray Analysis • Once researchers have established that a SNP pattern is associated with a particular drug response they can use SNP microarray technology to test an individual for that SNP to determine the drug dosage genomic DNA from an individual is hybridized to an array loaded with various SNPs • The sample DNA will hybridize with greater frequency only to specific SNPs associated with that person Those spots on the microarray will then fluoresce with greater intensity • Ask students to genotype patients and recommend dosage

8. Extension Snipping Away at the Problem – gives background information http://learn.genetics.utah.edu/units/pharma/phsnipping/ Beyond the Stethoscope Activity – online activity http://learn.genetics.utah.edu/units/pharma/phmedcare/