Timely Diagnosis of PAX2-Related Disorder by Rapid Whole-Genome Sequencing in a Critically Ill Neonate with Bilateral Renal Hypoplasia: A Three-Generation Case Report

Paired box 2 (PAX2) encodes a transcription factor essential for renal and ocular development, and its pathogenic variants cause a broad spectrum of PAX2-related disorders. We report the case of a critically ill neonate with antenatally detected bilateral renal hypoplasia accompanied by severe respiratory failure, suggesting a hereditary renal disorder. Rapid trio whole-genome sequencing identified a heterozygous PAX2 variant (c.187G>A, p.Gly63Ser) in the patient and her father, and extended genetic testing confirmed the same variant in the grandfather, establishing a threegeneration inheritance pattern. Early genomic diagnosis enabled timely nephrology consultation, initiation of peritoneal dialysis, and evaluation for potential extrarenal manifestations. A definitive diagnosis was achieved on the fifth day of life (with a 3-day turnaround time), underscoring the importance of rapid genomic testing and multigenerational genetic analysis in critically ill neonates with congenital renal hypoplasia and life-threatening respiratory failure. Such approaches can reveal hereditary transmission patterns and guide early management and genetic counseling for affected families.