Neonatal hypoglycaemia in severe succinyl-CoA:3-oxoacid CoA-transferase deficiency

Succinyl-CoA:3-oxoacid CoA-transferase (SCOT) deficiency is an inborn error of ketone body utilization, characterized by intermittent ketoacidotic crises and persistent ketosis. The diagnosis was suspected in a patient who presented with hypoglycaemia, ketoacidosis and coma at 4 days of age. The hypoglycaemic tendency was only observed during the first month of life. A novel macromolecular labelling assay in cultured skin fibroblasts using D-3-hydroxy[3-¹⁴C]butyrate supported the diagnosis. Subsequently, 9% residual SCOT activity and undetectable cross-reactive protein were noted in fibroblasts and the patient was found to be homozygous for the G324E SCOT gene mutation. By 7 years of age, recurrent episodes of ketoacidosis superimposed on persistent hyperketonaemia had resulted in over 25 hospitalizations requiring intravenous fluid, glucose and sodium bicarbonate therapy. He has had normal growth but developmental delay and attention deficit–hyperactivity disorder. A continuous intravenous glucose infusion at 38 mol (6.8 mg)/kg per min reduced plasma total ketone levels from greater than 1.5 mmol/L to less than 0.5 mmol/L after 48 h. This indicates that patients with SCOT deficiency do not always manifest ketosis with administration of a sufficient amount of carbohydrates, but that even under such conditions hyperketonaemia is difficult to eliminate completely. The presence of hypoglycaemia does not exclude the diagnosis of SCOT deficiency in infancy.     

Nitration of succinyl-CoA:3-oxoacid CoA-transferase in rats after endotoxin administration

The tyrosine nitration of proteins has been observed in diverse inflammatory conditions and has been linked to the presence of reactive nitrogen species. From many in vitro experiments, it is apparent that tyrosine nitration may alter the function of proteins. A limited number of experiments under in vivo conditions also demonstrate that protein nitration is associated with altered cellular processes. To understand the association of protein nitration with the pathogenic mechanism of the disease, it is essential to identify specific protein targets of nitration with in vivo or intact tissue models. Using anti-nitrotyrosine antibodies, we demonstrated the accumulation of nitrotyrosine in a 52-kDa protein in rat kidney after lipopolysaccharide treatment. The 52-kDa protein was purified and identified with partial sequence as succinyl-CoA:3-oxoacid CoA-transferase (SCOT; EC ). Western blot analysis revealed that the nitration of this mitochondrial enzyme increased in the kidneys and hearts of lipopolysaccharide-treated rats, whereas its catalytic activity decreased. These data suggest that tyrosine nitration may be a mechanism for the inhibition of SCOT activity in inflammatory conditions. SCOT is a key enzyme for ketone body utilization. Thus, tyrosine nitration of the enzyme with sepsis or inflammation may explain the altered metabolism of ketone bodies present in these disorders.     

Two siblings with episodic ketoacidosis and decreased activity of succinyl-CoA:3-ketoacid CoA-transferase in cultured fibroblasts

Summary Succinyl-CoA:3-ketoacid CoA-transferase deficiency leads to a severe ketoacidosis presenting in infancy. We describe two siblings of African ancestry who presented with repeated episodes of ketoacidosis. Both had a positive test for salicylate in the absence of salicylate ingestion. Analysis of urine for organic acids revealed the presence of acetoacetate and 3-hydroxybutyrate. Succinyl-CoA:3-ketoacid CoA-transferase activities in cultured fibroblasts were 11% and 18% of control values.     

Heterozygous protein-S deficiency: a study of a large kindred

Another family with protein-S deficiency is described here. The defect is characterized by a reduced level of total protein-S antigen; in addition, a markedly reduced level of free protein-S antigen was found. We have studied 20 family members. Ten of them showed reduced levels of protein-S antigen. Five of the affected patients manifested 'thrombophilia'. All the symptomatic patients developed the first thrombotic event at a young age. Heparin and oral anticoagulants were useful for the treatment of the acute phase of the thrombotic events, and in 1 symptomatic patient, the life-long oral anticoagulation treatment was effective in preventing relapses. On the other hand, all the symptomatic but untreated family members developed several recurrent thrombotic episodes.     

Mitochondrial acetoacetyl-CoA thiolase deficiency: basal ganglia impairment may occur independently of ketoacidosis

Background

Mitochondrial acetoacetyl-CoA thiolase (T2) deficiency affects ketone body and isoleucine catabolism. Neurological impairment may occur secondary to ketoacidotic episodes. However, we observed neuromotor abnormalities without ketoacidotic events in two T2-deficient families. We hypothesized that the neurological signs were related to the genetic defect and may occur independently of ketoacidotic episodes. We therefore conducted a retrospective review on a French T2-deficient patient series searching for neuromotor impairment.

Methods

In total, 26 cases were retrospectively analysed for clinical, biological and neuroimaging data.

Results

Neurological findings were observed for 6/26 (23%) patients. Among these, two had never experienced ketoacidotic episodes, though they developed extrapyramidal signs with putamen involvement. Two of the other four patients developed neurological abnormalities before the first ketoacidotic crisis, with putamen involvement in one case. The third patient developed extrapyramidal symptoms more than 10 years after the initial decompensation with globus pallidus involvement. The last patient developed extrapyramidal signs immediately after a severe ketoacidotic crisis with putaminal lesions.

Conclusions

Most T2-deficient patients achieved normal neurodevelopment. However, on account of the role of T2 in isoleucine catabolism, these patients are potentially exposed to accumulation of toxic isoleucine-derived metabolites, which may contribute to neurological impairment. Our findings confirm previous observations that neurological symptoms in T2 deficiency may occur unrelated to ketoacidosis. The role of protein restriction as a preventive measure against neurological symptoms could not be established in this study and deserves further evaluation. Long-term follow-up data on children diagnosed by newborn screening may clarify the pathogenesis of this neurometabolic association.

     

Heterozygous carriers of classical phenylketonuria in a sample of the turkish population: Detection by a spectrofluorimetric method

Summary Blood obtained by finger prick from 209 presumed normal homozygotes and 42 heterozygotes for classical PKU was analysed for plasma phenylalanine (Phe) and tyrosine (Tyr) by a fluorimetric method. Subjects were tested near midday and 3 hours after a protein-rich breakfast. The plot of Phe/Tyr (micromolar ratio) against Phe²/Tyr, permitted the detection of 11 heterozygotes among 209 controls. The accuracy of this method was checked by computation of a stepwise multivariate discriminant analysis, using Phe and Tyr (µmol/L), Phe/Tyr micromolar ratio and Phe²/Tyr as variables. Ten of the 11 subjects were recovered with a percentage of correct classification of over 90%, while one case had a percentage of 89.45%. The PKU gene frequency was found to be 1/19. This emphasizes the importance of a screening programme for PKU gene carrier status in Turkey.     

Underestimation of acute pancreatitis: patients with only a small increase in amylase/lipase levels can also have or develop severe acute pancreatitis

BACKGROUND: In most treatment studies on acute pancreatitis, pancreatologists base their diagnosis on amylase/lipase levels more than three times above the upper limit of normal (>3n) and thus exclude patients with smaller enzyme level increases. The recommendations derived from the results of treatment studies do not take into account such patients. Non-pancreatologists frequently believe that only patients with high enzyme levels have a serious prognosis. AIMS: To question the assumption that high enzyme levels indicate severe, and conversely low enzyme levels indicate mild, acute pancreatitis. PATIENTS/METHODS: This retrospective study includes 284 consecutive patients with a first attack of acute pancreatitis. The cause was biliary in 114 (40%) patients, alcoholism in 83 (29%), other in 21 (7%), and unknown in 66 (23%). Patients were divided into two groups according to their serum enzyme levels (amylase: 3n, n = 196; lipase: 3n, n = 233). Renal impairment, indication for dialysis and artificial ventilation, development of pseudocysts, necessity for surgery, and mortality were taken as parameters of severity. RESULTS: The incidence of severity was the same for both the 3n groups. CONCLUSIONS: The severity of acute pancreatitis is independent of the elevation in serum amylase/lipase level (3n) on admission. Patients with only a slight increase can also have or develop severe acute pancreatitis. Patients with 相似文献   

Succinyl-CoA:3-ketoacid transferase (SCOT) deficiency in a new patient homozygous for an R217X mutation

SCOT deficiency presents with persistent excess of ketones leading to ketoacidosis. Here we report patient GS15, homozygous for a novel R217X mutation, who had the first apparent ketoacidotic crisis at 8 months of age. Before confirmation of diagnosis, daily dialysis was the only mechanism by which to normalize her persistent metabolic acidosis of unknown aetiology.     

Ornithine transcarbamylase deficiency: adult onset of severe symptoms

Deficiency of ornithine transcarbamylase, an enzyme in the urea cycle, results in hyperammonemia. The X-linked recessive inheritance results in neonatal death of affected males but a variable symptomatic pattern in females, with onset of symptoms in childhood. We report the cases of two heterozygous women with onset of severe symptoms (encephalopathy and focal neurologic deficits) in adulthood.     

Heterozygous alpha-I antitrypsin deficiency as a co-factor in the development of chronic liver disease: a review

Alpha-I antitrypsin (AIAT) is an acute-phase protein that is produced in liver cells. AIAT deficiency is a hereditary disease which is defined by the hepatic production of an abnormal protein that can not be released into the plasma. This leads to deficiency of plasma AIAT and subsequently to an impaired protection against proteases, resulting in pulmonary disease. Accumulation of the abnormal protein in hepatocytes can lead to liver damage. Serum level measurement, phenotyping and liver biopsy can be used for establishing the diagnosis. Homozygous AIAT deficiency can cause neonatal hepatitis; in adults end-stage liver disease, cirrhosis and hepatocellular carcinoma can develop. There are strong arguments to consider heterozygous AIAT deficiency as an important co-factor in the aetiology of chronic liver disease. Studies have shown that AIAT heterozygosity can be considered a modifier for hepatitis C virus, end-stage liver disease, cirrhosis and hepatocellular carcinoma. The accumulation of AIAT in the hepatocytes occurs more profoundly in a diseased liver, and as a consequence it affects the natural course of the liver disease. Therapeutic options include augmentation therapy (infusion of purified human plasma AIAT) in pulmonary disease; in end-stage liver disease liver transplantation is an option. For the future, other interventions such as gene therapy or strategies to inhibit polymerisation are promising.     

Alcoholic ketoacidosis associated with multiple complications: report of 3 cases

We report 3 patients with alcoholic ketoacidosis (AKA). All had a history of excessive intake and abrupt termination of alcohol. They showed tachypnea, tachycardia, abdominal tenderness, and epigastralgia. Metabolic acidosis with an increased anion gap, decreased PaCO2 and ketonemia were present. One patient whose ratio of 3-hydroxybutyric acid to acetoacetic acid was 4.0 was associated with diabetic ketoacidosis. All patients were successfully hydrated with electrolyte, glucose and thiamine. Complications such as liver dysfunction, lactic acidosis, acute pancreatitis, Wernicke's encephalopathy, rhabdomyolysis and heart failure were present. Attention should be paid to multiple complications in the treatment of AKA.