In addition, COL4A3, COL4A4 or COL4A5 mutations are found in 10–30% of patients with focal and segmental glomerulosclerosis (FSGS) [4, 14], and Dr. Moin Saleem reported that some patients with features consistent with steroid-resistant nephrotic syndrome had COL4A variants on screening with a 70-gene renal panel. Here, COL4A3 is linked to focal segmental glomerulosclerosis.