The list of rare inherited disorders with renal involvement is rapidly growing. Many are single gene diseases affecting children, but cases are not restricted to pediatrics and diagnosis is often difficult and delayed. The expanding use of next-generation sequencing techniques is expected to discover new diseases, to challenge the definition of rarity, to accelerate and shake up our diagnostic paradigms, to promote 'deep phenotyping', and ultimately improve disease ontology. Rare renal diseases are exemplary of a transition from pediatric to adult-type care and pluridisciplinary approach, necessitating cooperation between geneticists, nephropediatricians, adult nephrologists, other physicians, nurses, social workers, and dietitians. They have raised new ethical issues, not only in genetic counseling, but also in public health, regarding equity, and distribution of care. Patient's organizations have grown and have been very active to promote information and research. Efforts are underway to create interoperable patient's registries and ultimately worldwide networks gathering patients, researchers, clinicians, pharmaceutical industry, and health authorities. Progress in genetics and pathophysiological mechanisms will hopefully increase the number of efficient orphan medicinal products. Finally, new frontiers set by rare nephropathies may improve the understanding, treatments, and outcomes of more frequent renal diseases.