Juvenile nephronophthisis is an inherited disorder, which mainly affects children. Patients with this disease typically develop cysts and fibrosis in the kidney, which can leads to production of large volume of urine (polyuria), excessive liquid intake (polydipsia), and appearance of protein in the urine (proteinuria). Eventually, the symptom will progress to end-stage kidney disease, which will require dialysis or a kidney transplant in order for the patient to survive. Besides the kidney problems, some patients can also develop blindness, liver problems, severe global developmental delay or intellectual disability, and neurologic involvement in which the cerebellum is affected. This disease is caused by pathogenic variants in the NPHP1 gene.