COL4A4 and glomerular disorder: It is known that mutations in LAMB2 can cause FSGS, (33) the GBM provide a mechanical foothold for its adjacent cells such as podocyte, LAMB2 and COL4A4 are the components of the GBM, the mutation of COL4A4 may cause glomerular disease through the same or different functional pathway, some mechanism study need to be further studied.