focal segmental glomerulosclerosis 9 (MONDO_0014539) is any focal segmental glomerulosclerosis in which the cause of the disease is a mutation in the CRB2 gene. Also known as: CRB2 focal segmental glomerulosclerosis, FSGS9, focal segmental glomerulosclerosis caused by mutation in CRB2, focal segmental glomerulosclerosis type 9.