[Congenital disorder of glycosylation type 1b. Experience with mannose treatment]. / Defecto congénito de glucosilación tipo Ib. Experiencia en el tratamiento con manosa.

Congenital disorders of glycosylation (CDG) are recessively inherited multisystemic disorders resulting from several genetic defects affecting the assembly, transfer or processing of oligosaccharides onto proteins and other glycoconjugates. CDG type Ib is due to a deficiency of phosphomannose isomerase (PMI) encoded by the MPI gene. PMI catalyzes the interconversion of fructose-6-P and mannose-6-P. The clinical phenotype is characterized by gastro-intestinal and hepatic symptoms. In contrast to most CDG patients, there is no neurological affectation. It's a mannose treatable disorder. We report the first recognised case of CDG Ib in Spain. He presented at 6 months with hypoglycaemia, failure to thrive and hypertransaminasaemia. He subsequently developed an enteropathy with subtotal villous atrophy on biopsy. The %CDT was very high and he presented with a type 1 pattern in transferrin isoelectric focusing. PMI activity in fibroblasts was very deficient. Mutations in MPI gene at R219Q and R56fs were found. Clinical and biochemical parameters normalised after treatment with mannose 1 g/kg/day in 5 doses. CDG Ib should be considered in patients with hypoglycaemia, liver disease, enteropathy and hypercoagulability, in the absence of other common causes, and particularly if some of them are combined.

[Neonatal lactic acidosis caused by severe pyruvate carboxylase deficiency]. / Acidosis láctica neonatal debida a deficiencia aislada de piruvato carboxilasa.

A new patient with neonatal lactic acidosis due to pyruvate carboxylase deficiency is described. Since birth he developed vomiting, hypothermia, lethargy, irritability, hypoglycemia and severe metabolic acidosis. During admission a progressive deterioration was observed. Despite different attempted therapies patient died at 4 1/2 months of age. High levels of plasma and urine lactate and pyruvate were detected. Enzymatic studies in cultures skin fibroblasts and postmortem tissues showed a severe deficiency of pyruvate carboxylase.