Resolving Severe Oligohydramnios as an Early Prenatal Presentation of Renal Coloboma Syndrome - a Report of Two Generations

Renal coloboma syndrome (RCS) is an autosomal dominant disorder associated with the PAX2 gene. With variable expressivity, renal and ocular abnormalities are reported in a majority of individuals affected. We highlight a mother and her newborn with RCS, both presenting prenatally, showing self-resolving severe oligohydramnios as an early prenatal finding.

Identification of candidate PAX2-regulated genes implicated in human kidney development

PAX2 is a transcription factor essential for kidney development and the main causative gene for renal coloboma syndrome (RCS). The mechanisms of PAX2 action during kidney development have been evaluated in mice but not in humans. This is a critical gap in knowledge since important differences have been reported in kidney development in the two species. In the present study, we hypothesized that key human PAX2-dependent kidney development genes are differentially expressed in nephron progenitor cells from induced pluripotent stem cells (iPSCs) in patients with RCS relative to healthy individuals. Cap analysis of gene expression revealed 189 candidate promoters and 71 candidate enhancers that were differentially activated by PAX2 in this system in three patients with RCS with PAX2 mutations. By comparing this list with the list of candidate Pax2-regulated mouse kidney development genes obtained from the Functional Annotation of the Mouse/Mammalian (FANTOM) database, we prioritized 17 genes. Furthermore, we ranked three genes—PBX1, POSTN, and ITGA9—as the top candidates based on closely aligned expression kinetics with PAX2 in the iPSC culture system and susceptibility to suppression by a Pax2 inhibitor in cultured mouse embryonic kidney explants. Identification of these genes may provide important information to clarify the pathogenesis of RCS, human kidney development, and kidney regeneration.

Minor dysmorphic features in a patient with papillorenal syndrome – A Case Report

Papillorenal syndrome, also known as renal coloboma syndrome, is characterised by congenital optic disc anomalies and renal abnormality. The syndrome causes mutations in the PAX2 gene, which plays a critical role in embryogenesis. Other related anomalies are less commonly observed. To our knowledge, ours is the first case reported in the literature in which Papillorenal syndrome accompanied various dysmorphic features. Keywords: Renal coloboma syndrome; PAX2-related disorder; coloboma of optic nerve, multicystic dysplastic kidney; eye abnormalities Continuous...

PAX2 variant associated with bilateral kidney agenesis and broad intrafamilial disease variability

Pathogenic variants in PAX2 have previously been associated with renal coloboma syndrome. Here we present a novel variant c.68T>C associated with bilateral kidney agenesis, minimal change nephropathy, ureteropelvic junction obstruction, duplex kidney with hydronephrosis of upper pole system and bilateral kidney hypoplasia within the same family. Additionally, two family members were found to have optic nerve abnormalities further supporting the impact of the PAX2 variant. This is the first report of a PAX2 variant associated with bilateral kidney agenesis.