NPHP1, the gene that encodes the protein nephrocystin-1 has been identified to be mutated in Juvenile Nephronophthisis, an autosomal recessive cystic kidney disorder that is the most frequent genetic cause of the end-stage renal disease (ESRD) in children and young adults. NPHP1 is the major subtype leading to pediatric end-stage renal disease (ESRD). Reports of adult NPHP1 are rare. NPHP1 presents a modular structure well in keeping with its role as an adaptor protein: it harbors an SH3 domain flanked by two glutamic acid-rich regions and a conserved C-terminal nephrocystin homology domain (NHD). Similar to other NPHP protein family members, its N-terminus contains a putative coiled-coil domain (NPHP1CC) that is supposed to play an important role in NPHP1 self-association and/or protein-protein interactions.