COL4A4 and focal segmental glomerulosclerosis: In addition, the development of NGS has revealed that FSGS can arise from mutated genes previously only implicated in AS and congenital urogenital anomalies (for example, COL4A3, COL4A4, PAX2 or SALL2) and will further accelerate the discovery of novel podocyte genes or genetic variants linked to FSGS.