Genetics is the branch of biology that deals with the mechanisms of heredity and its contribution to the similarities and differences among related organisms. Typically, genetic variation is caused by variation in the order of bases in the nucleotides in genes. Next generation sequencing allows researchers to directly sequence DNA within both coding regions and in the non-coding intron region of genes. Understanding genetic variation that leads to phenotypic changes is important for disease-risk profiling, drug development/selection, toxicity and understanding diversity.