In 104 pediatric carriers of a PAX2 LOF variant with CAKUT, hallmark kidney manifestations were (cystic) KHD (97% vs. 59% in patients with CAKUT and wildtype PAX2, P < 0.0001) and albuminuria (significantly more severe than in patients with (cystic) KHD and wildtype PAX2, P < 0.0001), suggesting a proteinuric effect of PAX2 LOF variants. This evidence concerns the gene PAX2 and congenital anomaly of kidney and urinary tract.