SLC3A1 and kidney disorder: In four patients (three adults and one child), we detected 12 variants in three genes known to be associated either with monogenic forms of proximal renal tubulopathy (SLC3A1) or with monogenic syndromes involving proximal tubule dysfunction (LRP2, CUBN), as well as in novel genes not related to monogenic nephropathies (SLC17A1, SLC9A3, and PDZK1).