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A patient with severe pyruvate carboxylase deficiency presented at age 11 weeks with metabolic decompensation after routine immunization. She was comatose, had severe lactic acidemia (22 mM) and ketosis, low aspartate and glutamate, elevated citrulline and proline, and mild hyperammonemia. Head magnetic resonance imaging showed subdural hematomas and mild generalized brain atrophy. Biotin-unresponsive pyruvate carboxylase deficiency was diagnosed. To provide oxaloacetate, she was treated with high-dose citrate (7.5 mol/kg(-1)/day(-1)), aspartate (10 mmol/kg(-1)/day(-1)), and continuous drip feeding. Lactate and ketones diminished dramatically, and plasma amino acids normalized, except for arginine, which required supplementation. In the cerebrospinal fluid (CSF), glutamine remained low and lysine elevated, showing the treatment had not normalized brain chemistry. Metabolic decompensations, triggered by infections or fasting, diminished after the first year. They were characterized by severe lactic and ketoacidosis, hypernatremia, and a tendency to hypoglycemia. At age 3(1/2) years she has profound mental retardation, spasticity, and grand mal and myoclonic seizures only partially controlled by anticonvulsants. The new treatment regimen has helped maintain metabolic control, but the neurological outcome is still poor.

We report on 4 children from 2 unrelated families who appear to have the lethal ARC syndrome (arthrogryposis, renal tubular dysfunction, and cholestasis) together with the additional findings of nephrogenic diabetes insipidus and cerebral anomalies, including deafness. With increased survival time in our patients, paucity of the intrahepatic bile ductules and cholestasis progressed to cirrhosis, growth was severely impaired, and severe mental retardation became apparent. No evidence was found for peroxisomal, chromosomal, or mitochondrial disorders. We propose to amend the ARC mnemonic to ARCC-NDI (A-Arthrogryposis, R-renal Fanconi, C-cerebral, C-cholestasis, NDI-nephrogenic diabetes insipidus) to name the major manifestations of this syndrome, several of which have not been appreciated.

Glycogen debranching enzyme and acid alpha-glucosdase are responsible for glycogen degradation in human. The formal enzyme is a multifunctional enzyme with two independent catalytic activities occurring on a single polypeptide, while the latter is a lysosomal enzyme which matures through extensive glycosylation and phosphorylation and proteolytic processing. Deficiency of glycogen debranching enzyme and acid alpha-glucosidase cause glycogen storage disease type III and II, respectively. Baculovirus/insect expression system was used to produce both GDE and GAA. Both enzymes were found to be catalytically and antigenically active. The majority of recombinant GDE is present in the medium (70%). Uptake experiment indicated that GAA produced in the insect cells could not be absorbed into the GSD type II patient fibroblasts through mannose-6-phosphate receptor mediated endocytosis. Uptake experiment combined with immunoblot analysis indicated there are differences in the posttranslational modification and processing between insect cells and mammalian cells.

Fryns syndrome is an autosomal recessive multiple congenital anomaly syndrome characterized by diaphragmatic hernia, unusual facies, and distal limb hypoplasia. It was first reported as a lethal condition. We report on a three-year-old survivor with Fryns syndrome, and provide a review on the outcome of other survivors. Patients who survive the neonatal period represent 14% of reported cases. Characteristics of survivors include less frequent diaphragmatic hernia and milder lung hypoplasia, absence of complex cardiac malformation, and neurologic impairment. Multiple central nervous system abnormalities have been reported in Fryns syndrome, including agenesis of the corpus callosum, Dandy-Walker abnormality, cerebellar heterotopias, cerebellar hypoplasia, enlarged ventricles, and hypoplasia of the olfactory bulbs. Our patient exhibited profound mental retardation. He had malformations of gyration and sulcation, particularly around the central sulcus, and hypoplastic optic tracts beyond the optic chiasm. Understanding of long-term outcome of survivors is important for counseling of families with Fryns syndrome. Careful brain examination is advised; however, a normal radiological brain examination does not preclude developmental delay. The spectrum of individual outcome and of associated anomalies indicates that individual evaluation, imaging for structural brain malformation, is strongly advised. © 1995 Wiley-Liss, Inc.

A 40-year-old woman presented with pro found muscle weakness resulting in failure to wean from a ventilator and persistent lactic acidosis after having recovered from a pneumonia complicated by adult respiratory distress syndrome, myocardial infarction, renal failure and shock. She had a 28 year history of chronic anemia and exercise intolerance. Anemia and thrombocytopenia persisted after admission. Nonobstructive hypertrophic cardiomyopathy was present. A stroke-like episode occurred. A mitochondrial myopathy with deficiencies in complexes IV and II was demonstrated, but no DNA defect has yet been found. This patient represents a distinct clinical presentation of a mitochondrial disorder characterized by late onset mitochondrial myopathy, chronic anemia, cardiomyopathy, and lactic acidosis. © 1994 Wiley-Liss, Inc.