Are Genetic Causes of Proteinuric Kidney Disease More Common in Patients with Echogenic Kidneys?

Background: In children with nephrotic syndrome, echogenic kidneys have been associated with increased steroid resistance and worse outcomes, but the association with genetic mutations has not been studied. We hypothesized that genetic causes of proteinuria and/or nephrotic syndrome (NS) will be more common in patients with persistent echogenic kidneys on ultrasound. Methods: We are performing a retrospective cross-sectional study including patients aged 0-21 years old seen at Children’s Hospital at Montefiore Einstein pediatric nephrology clinic between 01/01/2010-12/31/2023. Inclusion criteria are a diagnosis of proteinuria or NS confirmed by chart review with renal ultrasound imaging and genetic testing results available. Exclusion criteria include patients with kidney transplant at the time of diagnosis of NS or proteinuria or with systemic secondary causes (eg. Lupus). The primary outcome is the presence or absence of pathogenic mutations between subjects with echogenic vs. non-echogenic kidneys. Results: In a preliminary analysis of 72 subjects, 72% had echogenic kidneys and 35% had positive genetic testing. Using a Mann Whitney U test, subjects with positive genetic mutations had a statistically significant lower eGFR at diagnosis (p < 0.05). In contrast, there was no statistical difference between in eGFR at diagnosis between subjects with echogenic vs. non-echogenic kidneys. Additional data collection and detailed chart review is ongoing. Conclusion: This study may help us better understand how to identify patients with genetic causes NS and improve our screening protocols for genetic causes of NS/proteinuria.