There are several entities which differ in etiology, heredity and clinical symptoms.
note: many authors point out that cystic dysplasia Potter type II and IV result from a similar defect i.e. obstruction. They are seen as variants on a continuum rather then separate entities.
Minor cortical or glomerular microcysts are associated with miscellaneous sydromes and metabolic disorders e.g. trisomy 13, trisomy 18, Zellweger syndrome, several subtypes of chondrodysplasias. Renal cystic dysplasia is a cardial feature of autosomal recessive Meckel syndrome (characteristic trias: polydactyly, encephalocele, polycystic kidneys).