COL4A5 and hematuria, benign familial, 1: Patients may present with a wide spectrum of phenotypes, ranging from benign familial hematuria (BFH) or thin basement membrane nephropathy (TBMN) to end-stage renal disease (ESRD) resulting from various mutations, though the COL4A5-related BFH and TBMN were considered to be the milder subtypes of AS [5–7].