Abstract: Objective To explore the clinical characteristics of nephronophthisis caused by different NPHP gene variations. Methods The clinical data of nephronophthisis caused by different NPHP gene variations in 3 children were retrospectively analyzed. Results All of the 3 cases were female and had manifestations of anemia. Case 1 had extrarenal manifestations such as visceral inversion and abnormal liver function. Renal pathology of case 2 and 3 showed glomerular fibrosis, destruction of the integrity of the tubular basement membrane, tubule atrophy and infiltration of inflammatory cells in the renal interstitium. Case 1 and 2 had a family history of kidney disease. The younger brother of case 3 carried the same variation but did not have any clinical manifestations. NPHP gene variations were identified in all 3 cases by genetic testing. In case 1 , there were heterozygous variants of c. 388 A>C p.K 130 Q and c. 1465 G>A, p.V 489 M in NEK 8 /NPHP 9 gene, both of which were newly discovered. Case 2 had whole deletion of NPHP 1 gene. In case 3 , there was a homozygous variation of c.3218 T>G, p.L1073 * in NPHP3 gene, and the same homozygous variation site was found in her younger brother. All 3 patients had received renal transplantation and were under follow-up. Conclusions Nephronophthisis is a kind of clinical and genetic heterogeneous disease with no specific clinical manifestations, and genetic testing is helpful for diagnosis. Renal transplantation is an effective treatment for the progression from nephronophthisis to end-stage renal disease. The heterozygous missense variation of c.388A>C p.K 130 Q and the heterozygous variation of c.1465 G>A, p.V 489 M are newly discovered NPHP gene variants

Key words: NPHP gene variation; end-stage renal disease; nephronophthisis; renal transplantation