Collagen (COL4A) mutations are the most frequent mutations underlying adult focal segmental glomerulosclerosis. - Gast C; Pengelly RJ; Lyon M; Bunyan DJ; Seaby EG; Graham N; Venkat-Raman G; Ennis S (Nephrology, dialysis, transplantation : official publication of the European Dialysis and Transplant Association - European Renal Association, 2016)