Alport syndrome (AS) is associated with pathogenic variants in COL4A3, COL4A4 or COL4A5 and may present with proteinuria (some with FSGS on biopsy), and more commonly haematuria.6 The renal histology is characterised by an alteration of the glomerular basement membrane. Here, COL4A4 is linked to focal segmental glomerulosclerosis.