Abstract: FR-PO649
Associations Between Monogenic Causes of Nephrolithiasis and Initial 24-Hour Urine Studies in Pediatric Patients
Session Information
- Pediatric Nephrology - II
November 03, 2023 | Location: Exhibit Hall, Pennsylvania Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Pediatric Nephrology
- 1900 Pediatric Nephrology
Authors
- Ticho, Andrew, University of Wisconsin System, Madison, Wisconsin, United States
- Cannon, Shannon, University of Wisconsin System, Madison, Wisconsin, United States
- Goodman, Rocio, University of Wisconsin System, Madison, Wisconsin, United States
- Paloian, Neil J., University of Wisconsin System, Madison, Wisconsin, United States
Background
In children, testing for monogenic causes of nephrolithiasis offers the potential for early identification of high-risk individuals. The association between positive genetic tests for nephrolithiasis and 24-hour urine (24HU) findings in pediatric patients is unclear. We examined pediatric stone formers at our institution aiming to identify associations between 24HU parameters and the presence of lithogenic genetic variants.
Methods
We performed retrospective review of patients <18 years with nephrolithiasis who underwent genetic testing between 2019-2023 (Invitae Nephrolithiasis Panel, San Francisco, USA). We classified genetic tests as negative, variants of uncertain significance (VUS), and pathogenic (P) variants. Demographic and initial 24HU data were collected. Descriptive and comparative analyses were performed, including Kruskal-Wallis, Mann-Whitney-U and Spearman’s tests, with p<.05 considered significant.
Results
We identified 25 patients with nephrolithiasis who underwent both genetic and 24-hour urine testing, with 57% male and 43% female. The median age at the time of genetic test was 10.4 years. There 21 (60%) positive tests, with 19 (54%) VUS and 2 (6%) P variants (Table 1). Mean 24HU results from the cohort are shown (Table 2). On 24HU, all patients had 1 abnormal metabolic parameter. Six had abnormal values >2 standard deviation from mean for age/sex. There were no significant differences in values on 24HU studies between groups.
Conclusion
In this first study of associations between 24HU and nephrolithiasis genetic testing, we found no differences between pediatric stone formers with known variants and those with negative genetic tests. This suggests that genetic testing should not have an immediate impact on preventive care strategies, excluding conditions like primary hyperoxaluria. However, our study did not measure longitudinal outcomes; genetic disposition to stone disease may require more aggressive preventive care and metabolic management over time, so we recommend larger, longitudinal studies of pediatric patients with monogenic causes of nephrolithiasis.