PAX2 and posterior urethral valve: We found unilateral or bilateral (cystic) KHD not combined with PUV to be the hallmark CAKUT phenotype in carriers of a PAX2 LOF variant with all CKD stages, because this CAKUT type was almost exclusively found and significantly more frequent in patients with versus those without PAX2 LOF variants (101/104 [97%] vs. 174/294 [59%], P < 0.0001, Figure 4a and Table 3).