PAX2 Mutation-Related Renal Hypodysplasia: Review of the Literature and Three Case Reports

Abstract

Paired box 2 (<i>PAX2</i>)-related disorder is an autosomal dominant genetic disorder associated with kidney and eye abnormalities and can result in end stage renal disease (ESRD). Despite reported low prevalence of <i>PAX2</i> mutations, the prevalence of <i>PAX2</i> related disorders may have been underestimated in past studies. With improved genetic sequencing techniques, more genetic abnormalities are being detected than ever before. Here, we report three patients from two families with <i>PAX2</i> mutations identified within 1 year. Two patients were adults with chronic kidney disease and were followed for decades without correct diagnoses, including one with ESRD who had even undergone kidney transplant. The third patient was a neonate in whom <i>PAX2</i>-related disorder manifested as oligohydramnios, coloboma, and renal failure that progressed to ESRD within 1 year after birth. The phenotypes of <i>PAX2</i> gene mutation were shown to be highly variable, even within the same family. Early detection promoted genetic counseling and guided clinical management. The appropriate time point for genetic study is an important issue. Clinicians must be more alert for <i>PAX2</i> mutation when facing patients with congenital kidney and urinary tract anomalies, chronic kidney disease of unknown etiology, involvement of multiple systems, and/or a family history of renal disease.