Fetal dilated cardiomyopathy: an unsuspected presentation of methylmalonic aciduria and hyperhomocystinuria, cblC type.
OBJECTIVE
To report the prenatal presentation with dilated cardiomyopathy of methylmalonic aciduria and homocystinuria, cblC type [cobalamin C (cblC) deficiency] (MIM 277400).


METHODS
We describe a boy with cblC deficiency who presented prenatally with fetal ultrasound findings of dilated cardiomyopathy and growth restriction.


RESULTS
Dilated cardiomyopathy and growth retardation were detected in the third trimester of an initially uncomplicated pregnancy. Investigations were negative for chromosomal and other known causes. Growth restriction persisted but fetal heart function improved. Postnatal biochemical evaluation revealed combined methylmalonic acidemia and homocystinemia. Molecular investigations confirmed cblC deficiency. Initiation of treatment was followed by rapid clinical improvement.


CONCLUSIONS
Prenatal dilated cardiomyopathy can be the presenting sign of cblC deficiency. Inborn errors of metabolism should be considered in the investigation of prenatally diagnosed dilated cardiomyopathy in view of the possible impact on treatment and future reproductive options, in some of these conditions.
De Bie
Isabelle
I
Medical Genetics Division, Department of Pediatrics, Université de Montréal, Centre Hospitalier Universitaire Sainte-Justine, 3175 Côte Sainte-Catherine, Montréal, Québec H3T-1C5 Canada.
Nizard
Sonia Dal Pozzo
SD
Mitchell
Grant A
GA
D000328:Adult; D000592:Amino Acid Metabolism, Inborn Errors / Q000188:drug therapy; D002311:Cardiomyopathy, Dilated / Q000000981:diagnostic imaging / Q000209:etiology*; D018753:Diet, Protein-Restricted; D005260:Female; D005317:Fetal Growth Retardation / Q000000981:diagnostic imaging; D006712:Homocystinuria / Q000150:complications* / Q000175:diagnosis*; D006801:Humans; D006879:Hydroxocobalamin / Q000008:administration & dosage; D007231:Infant, Newborn; D007273:Injections, Intramuscular; D047908:Intracellular Signaling Peptides and Proteins; D008297:Male; D026901:Membrane Transport Proteins / Q000172:deficiency*; D033681:Mitochondrial Membrane Transport Proteins; D024101:Mitochondrial Proteins / Q000172:deficiency*; D011247:Pregnancy; D016216:Ultrasonography, Prenatal; D014815:Vitamins / Q000008:administration & dosage
D047908:Intracellular Signaling Peptides and Proteins; C527938:MMADHC protein, human; D026901:Membrane Transport Proteins; D033681:Mitochondrial Membrane Transport Proteins; D024101:Mitochondrial Proteins; D014815:Vitamins; D006879:Hydroxocobalamin