The human genome sequence has given us the view of the internal genetic scaffold around which human life is molded. We have inherited this heritage from our ancestors and through it we are connected to all life on earth. The sequencing of the human genome, amongst others, has led to the newer areas of healthcare and medicine. The human population is heterogeneous and consists of populations of immense ethnic diversity. There are considerable allelic differences between human populations as well as individuals within each ethnic group as a result of molecular heterogeneity of the genome. This, in turn, is responsible for differential allelic expression of genes endowing them with polymorphic characters. The molecular diversity within genes is responsible amongst others, of disease resistance or susceptibility or for that matter drug response. The objective of this article is to understand the nuances of the genetic repertoire and correlate it with disease gene identification, genes that have been or can be used as drug targets, identify candidate genes for drug development and recent trends in drug discovery. As regular clinical trials for drugs does not take into account the ethnic variations, it sometimes results in the differential response with respect to the efficacy and / or adverse reaction of the drug. Therefore the diverse ethnic populations of the world pose a challenge to the pharma industry. The concept of the personal medicine seems to be the answer to this problem. But it is a Herculean task requiring immense innovation in technology, is time consuming and is not a financially viable proposition at this point of time. An alternate approach would be to divide the populations in genetic cohorts and design drugs according to their genetic profile and haplotype. In addition, the ethical and legal bindings have also to be taken into consideration.