Kidney Function and Volume Progression in Unilateral Autosomal Dominant Polycystic Kidney Disease With Contralateral Renal Agenesis or Hypoplasia: A Case Series

Background

The occurrence of unilateral autosomal dominant polycystic kidney disease (ADPKD) with absence of the contralateral kidney has been described only rarely in the literature. Whether unilateral ADPKD is associated with faster disease progression is not known.

Study Design

Case series.

Setting & Participants

In a prospective cohort of 182 patients with ADPKD, we identified 3 patients with ADPKD and unilateral renal agenesis (2 patients) or severe hypoplasia (1 patient).

Measurements & Outcomes

Genetic analysis of the PKD1 and PKD2 genes was performed for all 3 patients. Serum creatinine levels and kidney volumes based on magnetic resonance imaging were determined twice, with a 6-month interval between measurements. Characteristics of the 3 patients were compared with age- and sex-matched controls from the full cohort.

Results

Genotyping of the 3 patients indicated that each had a different truncating mutation in the PKD1 gene. All 3 patients with unilateral ADPKD had renal volumes and progression rates greater than the mean values of their matched control groups. However, their glomerular filtration rates were well preserved, with estimated single-kidney creatinine clearances much greater than their controls.

Limitations

The number of cases in this study is small and time of follow-up was limited.

Conclusions

Unilateral renal agenesis or hypoplasia in patients with ADPKD might not be as rare as previously thought. Glomerular filtration rate was preserved despite unilateral renal absence, suggesting that renal compensatory mechanisms are well conserved in patients with ADPKD.

Index Words: Autosomal dominant polycystic kidney disease (ADPKD), unilateral renal agenesis (URA), magnetic resonance imaging (MRI), kidney volumetry