Chronic kidney disease (CKD) affects about 10% of the world population, with high morbidity and mortality. Genetic kidney diseases are increasingly recognized across all age groups and represent over 20% of all the causes of CKD. Accurate diagnosis allows necessary and unnecessary diagnostic procedures to be defined, avoids unnecessary treatments, improves prognosis prediction, identifies other family members for genetic counseling, and defines risks for living donor kidney transplantation. The research group coordinated by the Principal Investigator has recently developed an algorithm for the genetic diagnosis in pediatric and adult patients with CKD. The application of this personalized diagnostic algorithm on a local study led to a global diagnostic yield of 70%, suggesting that this strategy has the potential to substantially improve the diagnostic approach to patients with rare kidney disorders. The aim of this study is to validate and implement these results by extending its application in a multicentric study involving nephrology units that are referral centers for rare kidney diseases at national level.

Inclusion Criteria:

• proteinuria and/or hematuria in the absence of immune deposits on renal biopsy or immune-mediated glomerulopathy resistant to treatment (e.g., steroids, immunosuppressive drugs);
• family history of kidney diseases and/or consanguinity;
• extrarenal involvement;
• ultrasound evidence of at least two cysts in each kidney or hyperechogenic kidneys or nephrocalcinosis;
• persistent metabolic abnormalities (metabolic acidosis or alkalosis without kidney function impairment; calcium phosphate metabolism abnormalities) after exclusion of secondary causes;
• availability of clinical information.
• signed informed consent form

Exclusion Criteria:

• Refusal by the patient, parents, or legal guardian to provide informed consent.