There is genetic heterogeneity for DD, with ∼50%–60% of patients harbouring pathogenic variants in CLCN5 (chloride channel 5 gene; classified as Dent disease 1, DD1), some 15% with pathogenic variants in OCRL (oculo-cerebrorenal syndrome of Lowe gene, classified as Dent disease 2, DD2) and the remaining 25%–35% of patients having neither identifiable CLCN5 nor OCRL variants. The gene discussed is OCRL; the disease is Dent disease.