Bernstein (47,48) acknowledged, however, that not all dysplastic kidneys are associated with obstruction because the many familial multiple malformation syndromes argue for a genetic etiology.
The diverse entities characterized by the metanephric dysgenesis and LUT abnormalities of CAKUT are clustered together into the second category that accommodates their occurrence in sporadic, syndromic, and multiple malformation syndromes, while allowing for combinations of renal and LUT defects that can affect the same kidney.