This book offers expertly selected information to the readers regarding the field of Pharmacogenetics. The main purpose of the fast developing field of Pharmacogenetics is to identify the genetic factors responsible for the inter-individual variation of drug reaction. These factors make it convenient to classify the patients according to their treatment needs and hence, catalyze drug development and encourage customized, secure and effective treatments. This book provides a wide range of examples discussing various drugs for distinct diseases which reflect different stages of assessment and application. This book is comprehensive and a great source of information to scientists, professionals, practitioners and students alike, since it discusses not just the fundamentals of pharmacogenetics but also focuses on the applications of pharmacogenetics and latest developments in this field along with discussion on its limitations and proposal of ideas to overcome them.