With the decrease in sequencing costs, personalized genome sequencing will eventually become common in
medical practice. We therefore write this series of three reviews to help non-geneticist clinicians to jump into the fastmoving
field of personalized medicine. In the first article of this series, we reviewed the fundamental concepts in
molecular genetics. In this second article, we cover the key concepts and methods in genetic epidemiology including the
classification of genetic disorders, study designs and their implementation, genetic marker selection, genotyping and
sequencing technologies, gene identification strategies, data analyses and data interpretation. This review will help the
reader critically appraise a genetic association study. In the next article, we will discuss the clinical applications of genetic
epidemiology in the personalized medicine area.