Analysis of Underlying Diseases Associated with Kidney Stones in Korean Children and Adolescents

Background: Recently, the prevalence of kidney stones occurring in children and adolescents is increasing worldwide. The renal stones may appear as the clinical manifestations of underlying diseases or as a complication of the treatment. Therefore, this study aimed to analyze the underlying diseases including genetic causes and assess clinical outcomes of Korean children with nephrolithiasis. Methods: From January 2022 to December 2023, we retrospectively analyzed demographic data for patients aged 0 to 18 who were newly diagnosed with kidney stones using ultrasonography who visited Samsung Medical Center. Medical records including sex, gestational age, underlying disease, medication history, genetic analysis, and ultrasonography were retrospectively reviewed. The authors reviewed whether there was the underlying diseases or interventions related to kidney stones, and if such an underlying disease was not confirmed at the time of diagnosis, a genetic test such as whole exome sequencing was performed to distinguish hereditary kidney disease. Results: A total of 102 patients were diagnosed with kidney stones, and the male to female ratio was 1.04. The average age at diagnosis was 76 months. The underlying diseases were prematurity (45.0 %), tubulopathy after chemotherapy in pediatric patients with malignancy (13.8 %), hereditary disease confirmed through genetic testing (13.8%), and congenital anomalies of the kidney and urinary tract (CAKUT) with hydronephrosis or cyst (12.7%). In addition, underlying diseases such as congenital heart disease requiring diuretic treatment (5.9%), epilepsy taking anti-seizure medication that cause stones (3.9%), and inflammatory bowel disease (2.9%) were found. There were two cases in which these underlying diseases were not found. There were 2 cases that required urological surgery, and 1 case had renal function decline of chronic kidney disease stage 3. Conclusion: This study suggests that kidney stone may appear in association with various underlying diseases and be a clinical clue of hereditary disease. Therefore, the screening for stone in patients with relevant underlying disease or the active evaluation of the genetic cause should be considered. The prognosis for surgery or decline in renal function is relatively favorable.