Congenital nephrotic syndrome: a novel phenotype of type I carbohydrate-deficient glycoprotein syndrome.
Type I carbohydrate-deficient glycoprotein (CDG) syndrome is a genetic multisystem disorder generally without overt renal problems. We report a neonate with neurological abnormalities and congenital nephrotic syndrome of diffuse mesangial sclerosis type. Serum transferrin isoelectric focusing showed the typical abnormalities of type I CDG syndrome. Normal transferrin focusing findings in other patients with similar renal problems excluded the possibility of a secondary biochemical phenomenon. The diagnosis of type I CDG syndrome was confirmed by demonstration of a deficiency of phosphomannomutase. No evidence of pontocerebellar atrophy was found in imaging or at autopsy. We conclude that congenital nephrotic syndrome may occur in type I CDG syndrome, and that this diagnosis should be considered in patients with congenital nephrotic syndrome. Absence of pontocerebellar atrophy does not exclude the diagnosis of type I CDG syndrome.
van der Knaap
M S
MS
Department of Pediatrics, Free University Hospital, Amsterdam, The Netherlands.
Wevers
R A
RA
Monnens
L
L
Jakobs
C
C
Jaeken
J
J
van Wijk
J A
JA
D018981:Congenital Disorders of Glycosylation / Q000175:diagnosis*; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D009404:Nephrotic Syndrome / Q000151:congenital*; D010641:Phenotype