From Genes to Malformations: Molecular Mechanisms Driving the Pathogenesis of Congenital Anomalies of the Kidney and Urinary Tract.

Congenital Anomalies of the Kidney and Urinary Tract (CAKUT) are among the most common congenital malformations and the leading cause of chronic kidney disease in children. They arise when key steps in kidney development are disrupted, including ureteric bud induction, branching morphogenesis and nephron progenitor differentiation. These processes depend on coordinated transcriptional programs, signaling pathways, ciliary function and proper extracellular matrix (ECM) organization. Advances in whole exome and whole genome sequencing, as well as copy number variation analysis, have expanded the spectrum of known monogenic causes. Pathogenic variants have now been identified in major transcriptional regulators and multiple ciliopathy-related genes. Evidence also points to defects in central signaling pathways and changes in ECM composition as contributors to CAKUT pathogenesis. Clinical presentations vary widely, shaped by modifying effects of genetic background, epigenetic regulation and environmental influences such as maternal diabetes and fetal hypoxia. Emerging tools, including human kidney organoids, gene-editing approaches and single-cell or spatial transcriptomics, allow detailed exploration of developmental mechanisms and validation of candidate pathways. Overall, CAKUT reflects a multifactorial condition shaped by interacting genetic, epigenetic and environmental determinants. Integrating genomic data with experimental models is essential for improving diagnosis, deepening biological insight and supporting the development of targeted therapeutic strategies.