Jerome I. Rotter, an expert in translational genomics, joins JAMA Statistical Editor Roger J. Lewis to dive into Genome-Wide Association Studies (GWAS). They explore the differences between Mendelian and complex diseases, discussing how single base mutations lead to conditions like sickle cell anemia. The conversation covers polygenic diseases, highlighting the genetic variants behind ailments such as type 2 diabetes. They also tackle advancements in GWAS and the significance of SNPs, emphasizing the importance of diverse ethnic inclusion for reliable findings.