Uric Acid Based Renal Stones: Clinical, Metabolic and Genetic Characterization

Inclusion Criteria: * ⦁ Patients with unilateral renal stones (denovo or recurrent) who are candidates for endoscopic treatment (percutaneous nephrolithotomy). * Patients with preoperative NCCT findings of renal stone with stone density equal or less than 600HU. * Patients with dominant uric acid composition will be included as proven by postoperative stone analysis Exclusion Criteria: * ⦁ Patients with anatomical abnormalities precipitating stone disease e.g. ureteric stricture, ureteropelvic or ureterovesical junction obstruction, Urinary diversion, History of ureterovesical re-implantation * Patients with non-uric acid stones as proven by post-operative stone analysis.