PKHD1 and autosomal recessive polycystic kidney disease: Mutations in DZIP1L are a considerably rarer cause of ARPKD than PKHD1 mutations, maybe due in part to the larger size of PKHD1 relative to DZIP1L. Furthermore, our limited data suggest that the region encoding the N-terminus of DZIP1L may be more susceptible to mutations, a concept supported by in silico data that predict pathogenicity scores to decay toward the C-terminus.