Abstract: A young male was accidentally found renal cysts and renal insufficiency by influenza. He presented with polydipsia and had normal growth and development. The laboratory tests exhibited mild proteinuria, elevated serum creatinine and anemia. A kidney biopsy was performed and revealed chronic tubulointerstitial nephritis and cystic dilatation of renal tubules. A homozygous NPHP1 gene deletion mutation was detected by genetic sequencing. Finally, the patient was diagnosed with NPHP1 deletionrelated nephronophthisis.

Key words: nephronophthisis, renal cyst, renal biopsy