A most common and important source of genetic variability is known to be present uniformly throughout the genome is termed Single Nucleotide Polymorphisms or SNPs. Interest in SNPs lies in the fact that these polymorphisms may be responsible for the differences in disease susceptibility, drug metabolism and response to environmental factors between individuals. Even, if they are not directly responsible for the disease, they serve as genetic markers for a nearby locus that might be responsible.
We all know that DNA acts as a genetic material in most of the organisms on this planet earth. However, it is also clear that RNA also acts a genetic material, but only in some viruses. During the evolution, nature has considered DNA over RNA as genetic material, because DNA is more stable and more efficient than RNA.