Development of steroid-resistant nephrotic syndrome in a child with CAKUT-syndrome

BACKGROUND. One of the congenital anomalies of the kidneys and urinary tracts (CAKUT) is renal hypodysplasia/aplasia type 3 (PHDA3), caused by pathogenic variants in the GREB1L gene not associated with steroid-resistant nephrotic syndrome (SRNS). PGDA3 leads to chronic kidney disease (CKD). Variants in the UMOD gene associated with autosomal dominant tubulointerstitial kidney disease (ATKD-UMOD) also lead to CKD. The association of the GREB1L/UMOD genes with SRNS has not been previously described.THE AIM: to demonstrate a rare clinical case of SRNS in a child with CAKUT-syndrome.PATIENTS AND METHODS. A patient with CAKUT in the form of PGDA3 and ADTBP-UMOD is observed in the department of nephrology for 2 years. Post-infectious development of SRNS required a revision of the genetic screening.RESULTS. On the whole-genome sequencing were found a variability in the genes that cause CAKUT, with no candidate genes for SRNS.CONCLUSION. The described case stands out with clinical polymorphism of CAKUT and the variability of UMOD and GREB1L gene variants not associated with the development of SRNS. Infectious etiology of the development of SRNS is assumed. The patient has an intensive development of CKD stage 4, requiring a long-term follow-up in dynamics.