The advent of next-generation gene sequencing has greatly accelerated the discovery of new causative disease genes and has allowed comprehensive genetic testing to become a first-line diagnostic tool in many fields of medicine, including nephrology. As a result of the rapid progress in genetic medicine, a picture of tremendous genetic heterogeneity is emerging for many phenotypically uniform disease entities. In some disorders, genetic abnormalities have been identified unexpectedly in cellular structures and pathways hitherto unknown to be involved in the pathophysiology of the disease.