[Encephalopathy with methylmalonic aciduria and homocystinuria secondary to a deficient exogenous supply of vitamin B12].
BACKGROUND
A deficient supply of vitamin B12 can appear early during the first months of life, with haematological and neurological symptoms in the form of progressive encephalopathy.


METHODS
We describe two patients with megaloblastic anaemia and halted somatic and cranial perimeter development, accompanied by neurological involvement. Both of them had an increased rate of excretion of methylmalonic acid, as well as homocysteine, in urine with extremely low serum levels of vitamin B12, as compared to normal values. Both patients were breastfed only. The study of the mothers revealed asymptomatic pernicious anaemia. Treatment with hydroxycobalamine led to clinical recovery and psychomotor development progressively returned to normal.


CONCLUSIONS
Vitamin B12 deficiency due to a shortage of supply from the mother must be taken into account in the differential diagnosis of possibly reversible severe encephalopathies.
Gutiérrez-Aguilar
G
G
Servicio de Neurología, Unitat Integrada Hospital Sant Joan de Deu-Clinic, E-08950 Esplugues de Llobregat, Spain.
Abenia-Usón
P
P
García-Cazorla
A
A
Vilaseca
M A
MA
Campistol
J
J
D000592:Amino Acid Metabolism, Inborn Errors / Q000150:complications / Q000175:diagnosis / Q000473:pathology / Q000503:physiopathology; D001921:Brain / Q000378:metabolism / Q000473:pathology; D002675:Child, Preschool; D005260:Female; D006712:Homocystinuria / Q000209:etiology*; D006801:Humans; D007223:Infant; D008279:Magnetic Resonance Imaging; D008297:Male; D008764:Methylmalonic Acid / Q000652:urine*; D014806:Vitamin B 12 Deficiency / Q000150:complications / Q000175:diagnosis / Q000473:pathology / Q000503:physiopathology
D008764:Methylmalonic Acid