We present four cases with nephrotic syndrome, microcephaly and severe developmental delay. In the differential diagnosis the Galloway-Mowat syndrome, PEHO syndrome, ARC syndrome and the carbohydrate-deficient glycoprotein (CDG) syndrome are considered and discussed. One case may fall into the Galloway-Mowat spectrum and another case was diagnosed with the CDG syndrome. This case is the third report of a nephrotic syndrome as a part of the CDG syndrome. Two remaining cases with cerebellar and brain stem atrophy, and without major histopathological changes in the kidney were left without a definite unifying diagnosis and may well represent a different unknown condition. Although microcephaly and nephrotic syndrome with or without hiatus hernia has been equated with Galloway-Mowat syndrome in the literature, the brain and renal pathology in these reported cases has been very variable. It is likely that this group as a whole is aetiologically heterogeneous.