Turkiye Klinikleri Pediatri, cilt.34, sa.3, ss.136-139, 2025 (Scopus)
Non-glomerular diseases causing large proteinuria and albuminuria may lead to diagnostic difficulty. Cubilin, in association with megalin and amnionless, is required for proximal tubular reabsorption of proteins including albumin. Mutations in either the CUBN or the AMN gene result in Imerslund-Gräsbeck syndrome characterized by megaloblastic anemia and low molecular weight proteinuria. C-terminal mutations of CUBN, however, result in proteinuria, mainly albuminuria, without B12 malabsorption. Although renal functions remain normal over time, renal biopsy performed with suspicion of glomerular disease may reveal focal segmental glomerulosclerosis in some cases. We describe here an adolescent girl with chronic non-progressive proteinuria that was attributed to biallelic CUBN variants.