Alzheimer's disease (AD) is a highly prevalent condition that predominantly affects older adults. AD is a complex multifactorial disorder with a number of genetic, epigenetic and environmental factors which ultimately lead to premature neuronal death. Predictive and susceptibility genes play a role in AD. Early-onset familial AD is a rare autosomal dominant disorder. Genome-wide association studies have identified many potential susceptibility genes for late-onset AD, but the clinical relevance of many of these susceptibility genes is unclear. The genetic variation by susceptibility genes plays a crucial role in determining the risk of late-onset AD, as well as the onset of the disease, the course of the AD and the therapeutic response of patients to conventional drugs for AD. The newer understanding of the epigenetics in AD has also been highlighted. Recent advances in genetics, epigenetics and pharmacogenetics of AD pose new challenges to the future management of AD.