Asymptomatic critical hypoglycaemia: a dangerous presentation of glycogen storage disease type Ib in infancy

We report the case of a 3-month-old boy who presented with a 3-day history of respiratory tract infection and poor feeding. He was incidentally found to have profound hypoglycaemia, high-anion-gap lactic acidosis, ketonuria, hyperlipidemia, hepatomegaly, growth failure and neutropenia. Glycogen storage disease type Ib (GSD Ib), an autosomal recessive metabolic defect of the microsomal transporter glucose-6-phosphate-translocase, was suspected and confirmed by genetic testing. Treatment consisted of initial intravenous glucose and fluids to correct his lactic acidosis, followed by a strict dietary protocol consisting of soy-based infant formula enriched with glucose polymers from cornstarch and overnight gastrostomy feeds. CONCLUSIONS: GSD I should be considered in all young children presenting with hypoglycaemia and lactic acidosis. Presence of neutropenia further confirms GSD Ib. Even critical hypoglycaemia can be clinically unapparent in affected children.     

多羧酶缺乏患儿的临床与生化特点研究

目的了解多羧酶缺乏患儿的临床与生化特点及治疗情况。方法对5例多羧酶缺乏患儿进行临床观察，血生化、影像学和视听诱发电位检查及治疗反应的随访。结果1例为婴儿型多羧酶缺乏，表现为反复发作呼吸困难，嗜睡、昏迷，严重尿布疹。伴严重酸中毒，乳酸、血氨增高。4例为晚发型，其中脊髓受累2例，阵发性肌张力不全1例，惊厥和智力、运动倒退1例。部分患儿伴视力异常，智力、运动发育落后，皮疹、秃发和轻度酸中毒和乳酸升高。MRI示脊髓、脑白质、丘脑和桥脑均受累。视听诱发电位有传导延迟。治疗后表现均迅速改善或消失。结论多羧酶缺乏患儿临床多样，伴不同程度酸中毒、乳酸血症，经生物素治疗效果显著。     

Methylmalonic acidemia mimicking diabetic ketoacidosis in an infant

Methylmalonic acidemia (MMA) is an inherited organic acidemia usually present with recurrent episodes of acute illness. A typical episode is ushered in with ketonuria and vomiting, followed by acidosis, dehydration, and lethargy, leading, in the absence of aggressive treatment, to coma and death. We report an infant with MMA presented with diabetes symptoms. A 13-month-old girl complained of polydipsia, diuresis, and loss of weight. She had clinical signs of diabetic ketoacidosis such as dehydration, deep sighing respiration, smell of ketones, lethargy, and vomiting. Laboratory analysis showed hyperglycemia with acidosis and ketonuria. She was treated with parenteral fluid, electrolyte, and insulin infusion. Two days after her discharge, after having a meal rich in protein, she was brought unconscious with hepatomegaly, severe acidosis, ketonuria, and mild hyperammonemia. The absence of hyperglycemia and the presence of neurologic findings suggested organic acidemia. MMA was diagnosed because of methylmalonic aciduria and elevated C3 carnitine esters. Cranial magnetic resonance imaging (MRI) showed increased uptake of radiocontrast material in the basal ganglia bilaterally. A homozygous mutation in exon 4 of the MMAA gene was found in mutation analysis and confirmed the diagnosis of cblA-deficient MMA. Neurologic regression was improved with treatment of low-protein diet, vitamin B12, and l-carnitine. In patients born to consanguineous parents who admit during infancy with severe acidosis refractory to treatment, organic acidemias should be kept in mind, even they have high blood glucose. The definitive diagnosis is important because it may allow a specific treatment and a favorable evolution to prevent the sequelae.     

Severe complex I deficiency in a case of neonatal-onset lactic acidosis and fatal liver failure

We report a newborn admitted to our service on the 2nd day of life because of hypotonia and metabolic acidosis. A progressive hepatocellular dysfunction dominated the clinical picture and the patient died at 13 months of age because of severe hepatic failure. Persistent lactic acidosis, high ketone bodies levels and high-normal lactate/pyruvate and 3-hydroxybutyrate/acetoacetate molar ratios in plasma were found. Investigation of a liver biopsy revealed low activities of all the mitochondrial respiratory chain enzymes but in particular a marked decrease of complex I (NADH cytochrome c reductase) activity. All respiratory chain enzyme activities were normal in cultured skin fibroblasts. Mitochondrial DNA analysis failed to detect any major rearrangements. Although only a few cases have been reported so far, it is becoming clear that liver should be considered as one of the organs involved in oxidative phosphorylation disorders. The finding of unexplained progressive liver failure with poor neurological conditions, lactic acidaemia and ketonuria strongly warrants investigation for a respiratory chain disorder. Moreover, the finding of normal respiratory enzyme activities in a tissue other than liver does not rule out the existence of an oxidative phosphorylation disorder in patients with hepatocellular disease of unexplained origin.     

Biotin-reversible neurodegenerative disease in infancy

Two siblings with consanguineous parents began having myoclonic jerks at age 5 months after introduction of mixed feeding. There was later developmental regression. The elder girl died without diagnosis aged 1 year, after prolonged continuous hyperventilation. The younger sibling did not have metabolic acidosis when first investigated for myoclonus and hypotonia aged 5 months. At 9.5 months, when intermittently decerebrate and hyperventilating, she had a metabolic acidosis with elevated blood lactic, pyruvic and beta-hydroxybutyric acids, and beta-hydroxyisovaleric aciduria. On the assumption that she had beta-methylcrotonyl-CoA carboxylase deficiency she was started on biotin, 10 mg daily. Within 36 h there was dramatic clinical and biochemical improvement. Previously defective eye movement control and gaze became normal, hyperventilation ceased, and excessive organic acid excretion in urine was abolished. She remains on long-term biotin and at age 2 years her development appears normal in all respects. Fibroblast culture however revealed normal quantities of the enzymes beta-methylcrotonyl-CoA carboxylase, propionyl-CoA carboxylase and pyruvate carboxylase. Irrespective of niceties of enzyme and organic acid biochemistry, the clinician must be aware of biotin-reversible regressive brain disease which may present before manifest metabolic acidosis.     

Biochemical and clinical observations in four patients with fructose-1,6-diphosphatase deficiency

Three boys and one girl suffering from inherited fructose-1,6-diphosphatase (FDPase) deficiency are reported. All four patients had less than 25% residual hepatic FDPase activity. While in two out of three patients the enzyme deficiency was also expressed in leucocytes, one patient had a normal enzyme activity. Remarkably, three patients had pronounced neonatal hyperbilirubinaemia requiring exchange transfusion.     

Neonatal diabetes mellitus

Neonatal diabetes mellitus is a rare form of insulin dependent diabetes mellitus that present within the first month of life, lasting at least two weeks and requiring insulin therapy. Intrauterine growth restriction, failure to thrive, fever, dehydration, hyperglycemia and acidosis with or without ketonuria are the clinical features of the disease. We report four cases of neonatal diabetes mellitus; two of them had a transient course.     

Juvenile gout in methylmalonic acidemia

Methylmalonic acidemia (MMA) is an inborn error of metabolism caused by either deficiency of the enzyme methylmalonyl‐CoA mutase or a defect in adenosyl‐cobalamin synthesis. Chronic kidney disease is its common complication and, in combination with persistent acidosis, leads to hyperuricemia. Symptomatic hyperuricemia or gout, however, has not been reported in MMA. We herein report two pediatric cases of MMA caused by MMAB mutations (cblB defect) with renal tubular acidosis, chronic kidney disease, hyperuricemia, and gout. The clinical findings of gout in these cases included recurrent first metatarsophalangeal arthritis and/or tophi. The patients responded to treatment with colchicine and allopurinol.     

Isovaleric acidaemia: cranial CT and MRI findings

Isovaleric acidaemia is an inborn error of leucine metabolism due to deficiency of isovaleryl-CoA dehydrogenase, which results in accumulation of isovaleric acid in body fluids. There are acute and chronic-intermittent forms of the disease. We present the cranial CT and MRI findings of a 19-month-old girl with the chronic-intermittent form of isovaleric acidaemia. She presented with severe metabolic acidosis, hyperglycaemia, glycosuria, ketonuria and acute encephalopathy. Cranial CT revealed bilateral hypodensity of the globi pallidi. MRI showed signal changes in the globi pallidi and corticospinal tracts of the mesencephalon, which were hypointense on T1-weighted and hyperintense on T2-weighted images.     

Acute Shoshin beriberi syndrome immediately post–kidney transplant with rapid recovery after thiamine administration

Pediatric kidney transplant surgery is usually well tolerated, despite suboptimal physical conditioning that may result from uremia and nutritional deficiencies that accompany end‐stage kidney failure. Nutritional supplementation is used to overcome such deficiencies, especially for children needing dialysis. Thiamine, a water‐soluble vitamin also known as vitamin B1, is a critical cofactor in energy metabolism and may be competitively inhibited by the antimetabolite oxythiamine, a uremic toxin that accumulates in kidney failure. We report a case of a thiamine deficiency syndrome leading to overwhelming cardiac dysfunction, metabolic instability, and hemodynamic compromise, after otherwise uneventful kidney transplant surgery. Prior to transplant, this 14‐year‐old boy was treated with peritoneal dialysis and received thiamine supplementation. Post‐transplant, the patient first developed hyperglycemia, then lactic acidosis, and subsequently hemodynamic instability despite escalating treatment with volume resuscitation and inotropic medication. He made a rapid and complete recovery after administration of IV thiamine. This is the first reported case of Shoshin beriberi syndrome in a pediatric kidney transplant recipient. Inadequate dialysis may have been a key factor, with toxin accumulation and thiamine transporter downregulation contributing to his status. Functional thiamine deficiency should be considered as a potential treatable cause of early post‐transplant hemodynamic instability.     

Biotin-reversible neurodegenerative disease in infancy

Two siblings with consanguineous parents began having myoclonic jerks at age 5 months after introduction of mixed feeding. There was later developmental regression. The elder girl died without diagnosis aged 1 year, after prolonged continuous hyperventilation. The younger sibling did not have metabolic acidosis when first investigated for myoclonus and hypotonia aged 5 months. At 9.5 months, when intermittently decerebrate and hyperventilating, she had a metabolic acidosis with elevated blood lactic, pyruvic and β-hydroxybutyric acids, and β-hydroxyisovaleric aciduria. On the assumption that she had β-methylcrotonyl-CoA carboxylase deficiency she was started on biotin, 10 mg daily. Within 36 h there was dramatic clinical and biochemical improvement. Previously defective eye movement control and gaze became normal, hyperventilation ceased, and excessive organic acid excretion in urine was abolished. She remains on long-term biotin and at age 2 years her development appears normal in all respects. Fibroblast culture however revealed normal quantities of the enzymes β-methyl-crotonyl-CoA carboxylase, propionyl-CoA carboxylase and pyruvate carboxylase. Irrespective of the niceties of enzyme and organic acid biochemistry, the clinician must be aware of biotin-reversible regressive brain disease which may present before manifest metabolic acidosis.     

Intravenous glycerol therapy should not be used in patients with unrecognized fructose-1,6-bisphosphatase deficiency

BACKGROUND: In Asian countries, glycerol solution that contains fructose (5%) is often used for management of brain edema. However, glycerol and fructose may cause severe hypoglycemia and metabolic acidosis in patients with fructose-1,6-bisphosphatase (FBPase) deficiency, even under stable conditions. The aim of the present study was to determine whether glycerol solution was used for brain edema during acute metabolic decompensation of hypoglycemia and metabolic acidosis in patients with unrecognized FBPase deficiency in Japan and to examine a long-term prognosis of the patients who had this kind of severe metabolic decompensation with or without glycerol therapy. METHODS: A retrospective study of 20 children with FBPase deficiency was conducted, based on their medical records. RESULTS: Six of the 20 children were given glycerol solution for the presence or possibility of brain edema during acute metabolic decompensation of hypoglycemia and metabolic acidosis; two of the six patients administered with glycerol were given dialysis. In four patients treated with glycerol alone without dialysis, two had no brain edema before glycerol administration but it developed later after the administration. These four patients treated with glycerol alone died or developed severe neurological complications. Fourteen patients who were not treated with glycerol solution had no brain edema and showed good prognosis. CONCLUSIONS: Glycerol solution, which contains fructose in Asian countries including Japan, should not be used as an osmotic agent for treatment of brain edema in patients who have hypoglycemia and retention-type metabolic acidosis, until FBPase deficiency is ruled out by measuring blood concentration of lactate.     

Type B lactic acidosis and insulin-resistant hyperglycemia in an adolescent following cardiac surgery.

OBJECTIVE: To report the presence of type B lactic acidosis and insulin-resistant hyperglycemia following cardiopulmonary bypass in a pediatric patient. DESIGN: Case report. SETTING: Tertiary referral children's hospital pediatric intensive care unit. PATIENT: Fourteen-year-old child with hyperlactatemia and hyperglycemia following cardiac surgery. INTERVENTIONS AND RESULTS: We report a patient who following cardiopulmonary bypass for repair of his congenital heart disease developed type B lactic acidosis and hyperglycemia resistant to insulin therapy. Resolution of his hyperlactatemia and hyperglycemia occurred approximately 24 hrs postoperatively without apparent ill effect. CONCLUSIONS: Type B lactic acidosis is a phenomenon that may occur in the pediatric population in conjunction with insulin-resistant hyperglycemia. We observed that its resolution corresponded to improvement in the patient's hyperglycemia.     

Recurrent acidosis with hypoglycemia in an infant: fructose-1,6-diphosphatase deficiency

A seven months old infant presented with recurrent episodes of acidosis and hypoglycemia triggered by fasting and febrile infections. The diagnosis of fructose-1,6-diphosphatase deficiency was made by demonstrating the enzyme deficiency in a liver biopsy specimen. Fructose-1,6-diphosphatase is a key enzyme of gluconeogenesis. Fructose-1,6-diphosphatase deficiency results in hypoglycemia and lactic acidosis during episodes of fasting. Diagnosis is made preferably by liver biopsy. Treatment includes elimination of fructose and sucrose from the diet and avoidance of fasting. Acute attacks are treated by intravenous infusion of glucose and bicarbonate if necessary.     

Biochemical and histologic pathology in an infant with cross-reacting material (negative) pyruvate carboxylase deficiency

An infant with the acute neonatal form of pyruvate carboxylase deficiency (cross-reacting material negative) presented with severe intractable lactic acidosis within 4 h after birth. He also had hyperammonemia, hypercitrullinemia, and hyperlysinemia. Plasma glutamine was not elevated. He had a rapidly deteriorating clinical course with severe liver dysfunction, repeated septicemia and seizures; he was comatose and was on a ventilator throughout; death occurred at 8 wk of age. Skin fibroblast study confirmed the enzyme deficiency. Detailed biochemical parameters and histopathology of the brain and liver are presented. The evidence from this infant suggests that disturbances of intracellular oxaloacetate levels as a result of the primary enzyme defect might also contribute to deficiency in ATP generation which may explain the various other biochemical changes and liver pathology.     

Vitamin B1 deficiency as cause of a severe lactic acidosis and ileus symptoms

A 2-year-old boy presented with severe lactic acidosis and ileus symptoms after 3 weeks of parenteral nutrition. Diagnosis of thiamine deficiency was made only when further complications had occurred. This case shows the importance of sufficient substitution of thiamine during parenteral nutrition. In lactic acidosis of unknown etiology thiamine deficiency must be considered.     

Severe Lactic Acidosis and Renal Involvement in a Patient with Relapsed Burkitt's Lymphoma

We describe an 8-year-old patient with relapsed Burkitt's lymphoma who developed complex metabolic problems, including renal diabetes insipidus and severe lactic acidosis. The lactic acidosis responded temporarily to chemo-and radiotherapy but not to bicarbonate or thiamine administration. These metabolic changes were most likely due to the lymphomatous infiltration of the kidneys. Severe lactic acidosis, without evidence of thiamine deficiency, seems to be a very rare event in children with cancer.     

Pyruvate-carboxylase deficiency with urea cycle impairment

We report a case of pyruvate-carboxylase deficiency (EC 6.4.1.1, McKusick 26615) with neonatal onset of lactic acidosis, hyperammonemia, and citrullinemia. The patient developed signs of severe liver damage and died at 13 days of age after increasing metabolic acidosis and severe bleedings. The pyruvate-carboxylase activity in fibroblasts was less than 1% of controls, but normal activities of propionyl-CoA carboxylase (EC 6.4.1.3) and 3-methylcrotonyl-CoA carboxylase (EC 6.4.1.4) were found. To prepare for early prenatal diagnosis of pyruvate-carboxylase deficiency, the activity of the enzyme has been measured in chorionic villus samples.     

Pyruvate-Carboxylase Deficiency with Urea Cycle Impairment

ABSTRACT. We report a case of pyruvate-carboxylase deficiency (EC 6.4.1.1, McKusick 26615) with neonatal onset of lactic acidosis, hyperammonemia, and citrullinemia. The patient developed signs of severe liver damage and died at 13 days of age after increasing metabolic acidosis and severe bleedings. The pyruvate-carboxylase activity in fibroblasts was less than 1% of controls, but normal activities of propionyl-CoA carboxylase (EC 6.4.1.3) and 3-methylcrotonyl-CoA carboxylase (EC 6.4.1.4) were found. To prepare for early prenatal diagnosis of pyruvate-carboxylase deficiency, the activity of the enzyme has been measured in chorionic villus samples     

Neonatal congential lactic acidosis with pyruvte carboxylase deficiency in two siblings.

ABSTRACT. The authors report 2 familial cases of neonatal congenital lactic acidosis with pyruvate carboxylase deficiency in the liver. In both cases, disorders started immediately after birth and were characterized by major neurological symptoms, acute metabolic acidosis with hyperketonemia and hyperammonemia. Course was rapidly fatal despite intensive care, bicarbonate therapy and several therapeutic attempts with biotin and thiamine. Hyperlactacidemia was associated with dramatic increase in lactate/pyruvate ratio, without anoxia, in contrast with decreased /3 hydroxybutyrate/ acetoacetate ratio. This unusual metabolic pattern may be assumed to result from decreased oxaloacetate synthesis as a result of pyruvate carboxylase deficiency, and impairment of oxaloacetate dependent mitochondria1 redox shuttles. Post mortem enzymatic study of the liver and kidney showed biotin unresponsive total deficiency of pyruvate carboxylase. Other gluconeogenic enzyme activities were normal.