Description of 4 COL4A3-cIgAN families with the 4 cIgAN (P1‒4). (a) Family trees. (b) Evolution of repeated kidney biopsy for patients 1 to 4 (P1‒P4). C1, presence of extracapillary proliferation; E1, presence of endocapillary hypercellularity; ESKD, end-stage kidney disease; FSGS, focal segmental glomerulosclerosis; M1, presence of mesangial hypercellularity; RASB, renin–angiotensin system blockers; S1, presence of segmental glomerulosclerosis or adhesion; T1, presence of tubular atrophy/interstitial fibrosis.