Subsequent experiments in mice have confirmed that OCRL deficiency results in LRP2 mis-trafficking and defective endocytosis in the renal proximal tubule (Inoue et al., 2016; Festa et al., 2019), providing strong support for the original hypothesis of an LRP2 trafficking defect underlying the low molecular weight proteinuria seen in Lowe syndrome, and Dent-2 disease. Here, OCRL is linked to oculocerebrorenal syndrome.