# Pediatric Bilateral Hypoplastic Kidney Complicated With C1q Nephropathy: A Case Report

## TL;DR

A child with underdeveloped kidneys and kidney disease showed improvement over time with careful monitoring and treatment.

## Contribution

This case report highlights the favorable outcome of C1q nephropathy with mild kidney changes in a child with hypoplastic kidneys.

## Key findings

- The patient's hematuria resolved and proteinuria decreased by age seven.
- Kidney function was preserved at age 12 with only mild proteinuria.
- C1q nephropathy with mild mesangial proliferation can have a favorable prognosis without steroid treatment.

## Abstract

Progressive kidney dysfunction is often observed in children with bilateral hypoplastic kidneys. While glomerulopathy can exacerbate hypoplastic kidney progression, only IgA nephropathy and post-streptococcal acute glomerulonephritis have been noted in such cases. Herein, we present a case of a four-year-old female patient with bilateral hypoplastic kidney, kidney dysfunction, and significant proteinuria (urinary protein/creatinine ratio > 1 g/gCr), prompting referral owing to persistent hematuria since two years of age. Enalapril was initiated; however, urinary findings exhibited no improvement despite stable symptoms and kidney function. Subsequently, a kidney biopsy was performed at six years of age, and C1q nephropathy was diagnosed. Given the presence of only mild mesangial proliferation, steroids were not administered; enalapril treatment was continued. By seven years of age, the patient's hematuria had resolved, and proteinuria levels had decreased. On the latest follow-up at 12 years of age, kidney function was preserved with only mild proteinuria. This case report highlights the favorable prognosis of asymptomatic C1q nephropathy characterized by mild mesangial proliferation, even in patients with hypoplastic kidneys, renal dysfunction, and significant proteinuria. It emphasizes the significance of timely pathological evaluation for guiding appropriate interventions in such patients.