[Two patients with mitochondrial respiratory chain disease]. / Twee patiënten met een mitochondriale myopathie.

A 23-year-old woman and a 13-year-old boy were diagnosed with mitochondrial respiratory chain disease. The woman had muscle pain, fatigue and bilateral ophthalmoplegia--symptoms consistent with Kearns-Sayre syndrome. The boy had aspecific symptoms; eventually, reduced activity of complex 1 was found to be the cause of the mitochondrial respiratory chain disease in the boy and his mother, who had suffered from unexplained fatigue and muscle pain for 15 years. Mitochondrial diseases often involve several organ systems. Diagnosis can be difficult, because laboratory tests such as serum and urinary lactate and creatine kinase have low sensitivity and specificity. Biochemical assessment of muscle biopsy can reveal reduced oxidation ATP synthesis and sometimes specific abnormalities in individual protein complexes. DNA analysis may be helpful in demonstrating mitochondrial or nuclear mutations or deletions. The goal of treatment is to increase mitochondrial ATP production, improve clinical symptoms and enhance stamina. Replacement of the following substances (also referred to as cofactors) may be attempted: co-enzyme Q10, antioxidants (lipoic acid, vitamins C and E), riboflavin, thiamine, creatine and carnitine. Evidence regarding the optimal treatment approach is lacking; one usually has to rely on observing effects in the individual patient.

Hyperlipidemia in glycogen storage disease type III: effect of age and metabolic control.

While the presence of hyperlipidaemia in glycogen storage disease (GSD) type Ia and Ib is generally accepted, few investigators have adequately assessed lipid profiles of GSD III in children, in whom the presence of hyperlipidaemia may be most prominent. We analysed the lipid profiles in 44 GSD III patients from 6 months to 30 years of age. Hypertriglyceridaemia and hypercholesterolaemia were common in children younger than 3 years of age. Hypertriglyceridaemia correlated negatively with age, and may reflect increased severity of hypoglycaemia in this younger population. The presence of hyperlipidaemia during childhood in these patients identifies another GSD population that could be at risk for early cardiovascular disease (CVD). Consequently, the outcome of clinical trials investigating the vascular effect of hyperlipidaemia in GSD applies to types other than GSD I.

[Deficiency of the fatty-acid oxidising enzyme medium-chain acyl-CoA dehydrogenase (MCAD) in an adult, detected during a neonatal screening programme]. / Defïciëntie van het vetzuuroxidatie-enzym middenketen-acyl-coënzym-A-dehydrogenase (MCAD) bij een volwassene, opgespoord tijdens een proefproject voor neonatale screening]

In a trial running since October 2003 in the Dutch provinces of Friesland, Groningen, Drenthe and Overijssel neonatal screening for medium-chain acyl-CoA dehydrogenase (MCAD) deficiency has been added to the regular newborn screening programme for phenylketonuria, congenital hypothyroidism and adrenogenital syndrome. One of the questions to be answered by this trial is the cause of the strong variation in clinical expression of the disorder. Underdiagnosing is an important factor in this phenomenon, as shown by the data of a family of which the case histories of the two oldest children were discussed in this journal in 1965. Both children died at a very young age. Recently, MCAD deficiency was diagnosed in the youngest child of this family, now a 34-year-old woman. This family history illustrates the variable clinical expression of MCAD deficiency, which can cause death but can also run a milder or even subclinical course. Moreover, this family history shows that the underdiagnosis of MCAD deficiency in deceased children may be a cause of the apparently limited clinical detection rate of this disease, for which a simple treatment consisting of life-style and dietary measures is available after diagnosis.

Neutropenia, neutrophil dysfunction, and inflammatory bowel disease in glycogen storage disease type Ib: results of the European Study on Glycogen Storage Disease type I.

OBJECTIVE: To investigate the incidence, the severity, and the course of neutropenia, neutrophil dysfunction, and inflammatory bowel disease (IBD) in glycogen storage disease (GSD) type Ib. METHOD: As part of a collaborative European Study on GSD type I, a retrospective registry was established in 12 European countries that included all patients with GSD-I who were known at the centers and were born from 1960 to 1995. Of a total of 288 patients with GSD-I, 57 who had GSD-Ib form the basis of this study. RESULTS: Neutropenia (defined as an absolute neutrophil count <1 x 10(9)/L) was found in 54 patients. In 64% of the patients neutropenia was documented before the age of 1 year, but in 18% of the patients neutropenia was first noted between the ages of 6 and 9 years. Neutropenia was persistent in 5 patients and intermittent without any clear cyclical course in 45. Neutrophil function was investigated in 18 patients with neutropenia and was abnormal in all. Perioral infections were reported in 37 patients, perianal infections in 27 patients, and protracted diarrhea in 23 patients. Findings on colonoscopy and radiologic studies in 10 of 20 patients suspected to have IBD were abnormal in all. All patients with IBD, perioral infections, and perianal infections had neutropenia. CONCLUSIONS: Intermittent severe neutropenia is frequently found in patients with GSD-Ib. The study also indicates that IBD in GSD-Ib is underdiagnosed; up to 77% of the patients studied had evidence of IBD, all of whom had neutropenia. IBD was not detected in those with normal neutrophil counts. These findings support the notion that neutropenia and/or neutrophil dysfunction in GSD-Ib and IBD are causally related.

Glycogen storage disease type Ia: recent experience with mutation analysis, a summary of mutations reported in the literature and a newly developed diagnostic flow chart.

UNLABELLED: We studied the glucose-6-phosphatase (G6Pase) gene of 30 unrelated glycogen storage disease type Ia (GSD Ia) patients using single strand conformational polymorphism (SSCP) prior to automated sequencing of exons revealing an aberrant SSCP pattern. In all patients we could identify mutations on both alleles of the G6Pase gene, indicating that this method is a reliable procedure. A total of 14 different mutations were identified. R83C (16/60), 158delC (12/60), Q347X (7/60), R170X (6/60) and deltaF327 (4/60) were found most frequently. Nine other mutations accounted for the other 15 mutant alleles. Two DNA-based prenatal diagnoses were performed successfully. At present, 56 mutations in the G6Pase gene have been reported in 300 unrelated GSD Ia patients and an overview of these mutations is presented. Evidence for a clear genotype-phenotype correlation could be established neither from our data nor from those in the literature. With increased knowledge about the genetic basis of GSD Ia and GSD Ib and the high detection rate of mutations, it is our opinion that the diagnoses GSD Ia and GSD Ib can usually be based on clinical and biochemical abnormalities combined with mutation analysis instead of enzyme assays in liver tissue obtained by biopsy. A newly developed flowchart for the diagnosis of GSD I is presented. CONCLUSION: Increased knowledge of the genetic basis of glycogen storage disease type I provides a DNA-based diagnosis, prenatal DNA-based diagnosis in chorionic villus samples and carrier detection.

Liver transplantation for glycogen storage disease types I, III, and IV.

UNLABELLED: Glycogen storage disease (GSD) types I, III, and IV can be associated with severe liver disease. The possible development of hepatocellular carcinoma and/or hepatic failure make these GSDs potential candidates for liver transplantation. Early diagnosis and initiation of effective dietary therapy have dramatically improved the outcome of GSD type I by reducing the incidence of liver adenoma and renal insufficiency. Nine type I and 3 type III patients have received liver transplants because of poor metabolic control, multiple liver adenomas, or progressive liver failure. Metabolic abnormalities were corrected in all GSD type I and type III patients, while catch-up growth was reported only in two patients. Whether liver transplantation results in reversal and/or prevention of renal disease remains unclear. Neutropenia persisted in both GSDIb patients post liver transplantation necessitating continuous granulocyte colony stimulating factor treatment. Thirteen GSD type IV patients were liver transplanted because of progressive liver cirrhosis and failure. All but one patient have not had neuromuscular or cardiac complications during follow-up periods for as long as 13 years. Four have died within a week and 5 years after transplantation. Caution should be taken in selecting GSD type IV candidates for liver transplantation because of the variable phenotype, which may include life-limiting extrahepatic manifestations. It remains to be evaluated, whether a genotype-phenotype correlation exists for GSD type IV, which may aid in the decision making. CONCLUSION: Liver transplantation should be considered for patients with glycogen storage disease who have developed liver malignancy or hepatic failure, and for type IV patients with the classical and progressive hepatic form.

A convenient diagnostic function test of peripheral blood neutrophils in glycogen storage disease type Ib.

Neutrophils from patients suffering from glycogen storage disease type Ib (GSD-Ib) show several defects. one of which is a decreased rate of glucose utilization. In this study, we established experimental conditions to show the stimulation of the neutrophil respiratory burst by extracellular glucose. With phorbol-myristate-acetate as stimulus of the burst, the activity of the NADPH oxidase in GSD-Ib neutrophils hardly increased on addition of glucose. In control and GSD-type Ia neutrophils, a clear increase was observed. The lack of response to extracellular glucose in GSD-Ib neutrophils is correlated with the inability to raise intracellular glucose-6-P levels on glucose addition, thereby limiting the activity of the generation of NADPH in the hexose-monophosphate shunt. Our study shows the usefulness of this test for the diagnosis of neutrophil function abnormality in GSD-Ib patients.

Abnormal glutathione conjugation in patients with tyrosinaemia type I.

Previous studies have suggested that tyrosinaemia type I may be associated with reduced glutathione availability due to conjugation of tyrosinaemia-associated reactive intermediates with glutathione. In the present study, the glutathione/ glutathione S-transferase system of two tyrosinaemia patients and three healthy controls were characterized by administering the racemic sedative drug bromisoval, a probe drug for assessing glutathione conjugation activity in vivo. Furthermore, concentrations of glutathione and glutathione S-transferase class alpha (GSTA) isoenzymes as well as the glutathione S-transferase class mu phenotype were assessed in the blood of six tyrosinaemia patients. The excretion of bromisoval mercapturates in healthy children was comparable to that observed in healthy adults. Tyrosinaemia patients were found to have a very high urinary recovery of bromisoval mercapturates (> or = 60% of the dose compared to about 30% for healthy, age-matched children and adults), which could be attributed mainly to a higher urinary excretion of the mercapturate derived from S-bromisoval. Healthy children and adults predominantly excrete the (R)-bromisoval mercapturate. The differences in amount excreted as well as in stereoselectivity of the urinary excretion of bromisoval mercapturates in tyrosinaemia patients are possibly related to an increased activity of specific glutathione S-transferase isoenzymes. Plasma glutathione and blood cell glutathione disulphide concentrations in tyrosinaemia patients were normal. Low blood cell glutathione concentrations were in general found only in two patients with a poor clinical condition. These results indicate that, in contrast to previous suggestions, reduced glutathione availability is not a generalized problem in (stabilized) tyrosinaemia patients.

Type IIIb glycogen storage disease associated with end-stage cirrhosis and hepatocellular carcinoma. The Liver Transplant Group.

Type III glycogen storage disease (GSD) is a disorder of carbohydrate metabolism caused by a deficiency of debranching enzyme. Different subtypes with different clinical pictures have been recognized. During childhood and early adulthood, the symptoms generally regress, and normal adulthood appears possible in most patients without symptoms or signs of cirrhosis. We report on an adult patient with GSD who developed endstage cirrhosis and a small hepatocellular carcinoma. She had GSD subtype IIIb, i.e., there were no signs of cardiomyopathy, myopathy, or neuropathy. She underwent a successful transplantation, representing the first case treated this way for this indication to our knowledge, and she is doing well after 1 year. Debranching enzyme activity was absent both in the liver and in the leukocytes before transplantation. The debranching enzyme activity remained absent in the leukocytes after transplantation. We conclude that patients with GSD type III may develop end-stage cirrhosis and hepatocellular carcinoma and therefore need hepatological follow-up during adulthood.

Folate-responsive homocystinuria and megaloblastic anaemia in a female patient with functional methionine synthase deficiency (cblE disease).

This first detailed report of a female patient with functional methionine synthase deficiency due to the cblE defect describes treatment with several vitamins and cofactors and clinical progress for 17 years. Before treatment, major findings were microcephaly, psychomotor retardation, episodic reduced consciousness, megaloblastic anaemia, increased plasma free homocystine (> 20 mumol/L), low plasma methionine (< 10 mumol/L) and increased excretion of formiminoglutamate. On high-dose folic acid, biochemical abnormalities such as formiminoglutamate excretion and homocystinuria nearly normalized, but clinical and haematological abnormalities remained. On replacement of folate with methylcobalamin, alertness, motor function, speech and the electroencephalogram improved, biochemical features were similar, but the mean corpuscular volume increased. The best control was observed on a combination of folate and methylcobalamin. At 17 years of age she remains severely mentally retarded. In cultured fibroblasts methionine synthesis was reduced (0.03 nmol/mg/per 16 h, controls 2.4-6.9); methionine synthase activity was normal under high reducing conditions but decreased on limiting the reducing agent, dithiothreitol, to 5 mmol/L (18% of total, controls 51-81%); formation of methylcobalamin was low (4.5% of total cobalamins, control 57.5%) and complementation studies indicated the cblE defect. Methionine formation showed only minor increases in cells grown in folate- or cobalamin-supplemented medium. Serine synthesis, which was low in normal medium, increased with cobalamin supplementation. These studies suggest further heterogeneity within cblE mutants, show the difficulty of establishing the enzyme defect in vitro, and indicate a role for folate in addition to cobalamin in treatment.

Hereditary tyrosinemia type I: a new clinical classification with difference in prognosis on dietary treatment.

Hereditary tyrosinemia type I (McKusick 27670) is a heterogeneous disease with poor prognosis, yet there are few reports of the long-term prognosis. It is therefore difficult to decide on the treatment for individual patients. We have conducted an international survey of patients with tyrosinemia type I and examined the probability of survival on dietary treatment and the causes of death in 108 patients with tyrosinemia type I. The survival after the onset of symptoms varied with the age at onset; the earlier the symptoms developed the poorer the outlook. Liver failure and recurrent bleeding (67%), hepatocellular carcinoma (17%) and the porphyria-like syndrome with respiratory failure (10%) were the most common causes of death. The 1- and 2-yr survival probability after the onset of symptoms in patients in whom symptoms developed before 2 mo, between 2 and 6 mo and after 6 mo were 38%/29%, 74%/74% and 96%/96%, respectively. On the basis of these survival rates, a new classification--which is important with respect to choices in treatment--is proposed: very early (onset of symptoms < 2 mo), early (2 to 6 mo) and late presenting form (> 6 mo).

X-linked liver glycogenosis: localization and isolation of a candidate gene.

X-linked phosphorylase kinase (PHK) deficiency causes X-linked liver glycogenosis (XLG) which is the most frequent liver glycogen storage disorder in man. Recently we assigned XLG to the Xp22 chromosomal region by linkage analysis in two families segregating XLG. In this study a further localization of XLG in Xp22 was performed by extending the number of Xp22 markers, by extension of the number of family members from the two families of our previous study and by linkage analysis in four additional XLG families. Two-point linkage analysis revealed lod scores of 4.60, 5.73, 5.28, 8.62 and 5.14 for linkage between XLG and the DNA markers pXUT23 and pSE3.2-L(DXS16), pD2(DXS43), pTS247-(DXS197) and pPA4B(DXS207), respectively, all at 0% recombination. Linkage heterogeneity was not observed in this set of families. Multipoint linkage analysis increased the lod score for linkage between XLG and Xp22 to 16.79 relative to DXS197/DXS207. The position of the XLG gene was confirmed by analysis of recombinational events locating the XLG gene between DXS85 and DXS41. The XLG gene could not be mapped more precisely in this chromosomal region of approximately 20cM because of the absence of recombinational events between the XLG gene and the Xp22 markers. As we have previously shown that the rabbit liver alpha subunit of PHK (PHKA2) hybridizes to human Xp22, we isolated a human PHKA2 cDNA from a human hepatoma lambda gt11 cDNA library. Fluorescent in situ hybridization mapped human PHKA2 to Xp22. As this physical mapping coincides with the genetic mapping of XLG by linkage analysis, PHKA2 most probably harbours the mutation(s) responsible for XLG.

The long-term outcome of patients with glycogen storage disease type Ia.

Forty-one patients (16 females and 25 males) over 10 years of age from five different European centres were studied retrospectively. Of those patients 19 were below the 3rd percentile for height. Hypoglycaemia was still reported in 6 patients. Hepatomegaly was present in 39 out of 40, while 11 out of 27 reported patients had marked hepatomegaly (> 10 cm below the costal margin in the midclavicular line). Adenomas were detected in 11 out of 39 patients, alpha-1-fetoprotein was reported to be within normal limits in a total of 22 patients of whom 6 had adenomas. Blood cholesterol concentration was elevated in 31 out of 38 patients, in 7 greater than 10.0 mmol/l. Blood triglycerides were elevated in 29 out of 34 patients, in 8 patients greater than 4.0 mmol/l. Blood uric acid concentration was elevated in 19 out of 35 patients, 12 of them being treated with allopurinol. Mental development was reported to be normal in 32 out of 37 patients. Since limited information on treatment was available no significant differences between treatment groups could be detected. In order to evaluate the effect of treatment, 20 patients (10 females and 10 males) of one centre were studied before and after at least 5 years of treatment. This treatment consisted of frequent feedings during the day together with nocturnal gastric drip feeding. Patients were divided into responders (n = 16) and non-responders (n = 4) depending on their (change in) SDS (standard deviation score) for height. Liver adenomas were detected in 3 patients, of which one was a non-responder. Alpha-fetoprotein was normal in all patients.(ABSTRACT TRUNCATED AT 250 WORDS)

The long-term outcome of patients with glycogen storage diseases.

In this retrospective study from five centres, 139 patients over 10 years of age with glycogen storage disease types I, III, VI and IX are described. Almost half of the patients with glycogen storage disease type Ia had retarded growth and most had hyperlipidaemia. One-third of the patients had adenomas, although none of these showed malignant transformations. With increasing age the growth, liver size and hyperlipidaemia of patients with glycogen storage disease type III improve. However, there was a high incidence of myopathy and cardiomyopathy. Patients with glycogen storage disease types VI and IX had a normal growth pattern after childhood. Hepatomegaly and hypercholesterolaemia, however, were still present in half of the patients.

Urinary excretion of deuterated metabolites in patients with tyrosinemia type I after oral loading with deuterated L-tyrosine.

1. The metabolic fate of orally given deuterated L-tyrosine, 50 mg/kg body weight, was investigated in seven patients with tyrosinemia type I in order to obtain evidence that the primary defect is at the level of fumarylacetoacetase. 2. The absence of fumarylacetoacetase could be proved in liver biopsy specimens obtained from four patients. 3. All patients excreted deuterated succinylacetoacetate and deuterated succinylacetone was detected in six out of seven. The total amount of these compounds was rather low; maximal 8.3% of the dose. The peak of the excretion occurred 3-6 h after loading, indicating an endogenous formation of the metabolites. 4. All patients excreted deuterated 4-hydroxyphenyl acids, probably reflecting secondary 4-hydroxyphenylpyruvate dioxygenase deficiency connected with liver damage. 5. No evidence for other secondary routes of tyrosine metabolism was found.

Deficiency of fumarylacetoacetase in a patient with hereditary tyrosinemia.

A patient is described with type I tyrosinemia characterized by urinary excretion of succinylacetone together with increased excretion of tyrosine, p-hydroxyphenyllactic, p-hydroxyphenylpyruvic and p-hydroxyphenylacetic acids. Fumarylacetoacetase was measured in a liver biopsy and found to be very low compared to control liver. Furthermore the mass spectra of succinylacetone and fumarylacetoacetate (methoxime-TMS derivatives) are reported. Control jejunal mucosa, leucocytes and fibroblasts showed no enzyme activity; hence the prenatal diagnosis of this disease by measuring the fumarylacetoacetase activity in cultured amniotic fluid cells is not possible at present.