SIX1 mutations cause branchio-oto-renal syndrome by disruption of EYA1-SIX1-DNA complexes.

Urinary tract malformations constitute the most frequent cause of chronic renal failure in the first two decades of life. Branchio-otic (BO) syndrome is an autosomal dominant developmental disorder characterized by hearing loss. In branchio-oto-renal (BOR) syndrome, malformations of the kidney or urinary tract are associated.

Mutations in INVS encoding inversin cause nephronophthisis type 2, linking renal cystic disease to the function of primary cilia and left-right axis determination.

Nephronophthisis (NPHP), an autosomal recessive cystic kidney disease, leads to chronic renal failure in children. The genes mutated in NPHP1 and NPHP4 have been identified, and a gene locus associated with infantile nephronophthisis (NPHP2) was mapped. The kidney phenotype of NPHP2 combines clinical features of NPHP and polycystic kidney disease (PKD).

Confirmation of the ATP6B1 gene as responsible for distal renal tubular acidosis.

Primary distal renal tubular acidosis (dRTA) type I is a hereditary renal tubular disorder, which is characterized by impaired renal acid secretion resulting in metabolic acidosis. Clinical symptoms are nephrocalcinosis, nephrolithiasis, osteomalacia, and growth retardation. Biochemical alterations consist of hyperchloremic metabolic acidosis, hypokalemia with muscle weakness, hypercalciuria, and inappropriately raised urinary pH.