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Background Pyruvate dehydrogenase complex (PDHc) deficiencies are an important cause of primary lactic acidosis. Most cases result from mutations in the X-linked gene for the pyruvate dehydrogenase E1α subunit ( PDHA1 ) while a few cases result from mutations in genes for E1β ( PDHB ), E2 ( DLAT ), E3 ( DLD ) and E3BP ( PDHX ) subunits or PDH-phosphatase ( PDP1 ). Aim To report molecular characterization of 82 PDHc-deficient patients and analyze structural effects of novel missense mutations in PDHA1. Methods PDHA1 variations were investigated first, by exon sequencing using a long range PCR product, gene dosage assay and cDNA analysis. Mutation scanning in PDHX , PDHB, DLAT and DLD cDNAs was further performed in unsolved cases. Novel missense mutations in PDHA1 were located on the tridimensional model of human E1 protein to predict their possible functional consequences. Results PDHA1 mutations were found in 30 girls and 35 boys. Three large rearrangements, including two contiguous gene deletion syndrome were identified. Novel missense, frameshift and splicing mutations were also delineated and a nonsense mutation in a mosaic male. Mutations p.Glu75Ala, p.Arg88Ser, p.Arg119Trp, p.Gly144Asp, p.Pro217Arg, p.Arg235Gly, p.Tyr243Cys, p.Tyr243Ser, p.Arg245Gly, p.Pro250Leu, p.Gly278Arg, p.Met282Val, p.Gly298Glu in PDHA1 were predicted to impair active site channel conformation or subunit interactions. Six out of the seven patients with PDHB mutations displayed the recurrent p.Met101Val mutation; 9 patients harbored PDHX mutations and one patient DLD mutations. Conclusion We provide an efficient stepwise strategy for mutation screening in PDHc genes and expand the growing list of PDHA1 mutations analyzed at the structural level.

Background Deficiency of mitochondrial trifunctional protein (MTP) is caused by mutations in the HADHA and HADHB genes, which have been mostly delineated at the genomic DNA level and have not been always elucidated. Aim To identify mutations in a French cohort of 52 MTP deficient patients and the susceptibility of mutations generating premature termination codons (PTCs) to the nonsense mRNA mediated decay (NMD). Methods Mutation screening in fibroblasts was performed at the cDNA level and real-time RT-PCR was used to compare the levels of the different PTC-bearing mRNAs before and after a treatment of fibroblasts by emetine, a translation inhibitor. Results A mutation detection rate of 100% was achieved. A total of 22 novel mutations were identified, including a large-sized genomic deletion in HADHB gene. A high proportion of all identified mutations were non-sense, frameshift and splicing mutations, generating (PTCs), distributed essentially on HADHA coding regions. We could demonstrate that the majority of mutations resulting in PTCs conform to the established rules governing the susceptibility to NMD. Conclusion Our results emphasize the value of cDNA analysis in the characterization of HADHA and HADHB mutations and further strengthen the model of haploinsufficiency as a major pathomechanism in MTP defects.

A 22 year-old woman with tyrosinemia type I (HT1) married her first cousin who is heterozygous for the same FAH mutation for which the patient is homozygous. During her pregnancy she was treated with diet (prescribed tyrosine intake 300 mg/day), and nitisinone (60 mg/day). Median plasma tyrosine levels were 560 μmol/L (range: 375-838, n = 21) and nitisinone 51 μmol/L (range: 41-57, n = 3) during pregnancy. She gave birth to a clinically healthy girl affected with tyrosinemia type 1. Birth was normal (birth weight 2615 g) and the baby had normal liver function, normal plasma alpha-fetoprotein concentrations, low urinary excretion of phenolic acids and no detectable succinylacetone. At birth, the baby had hypertyrosinemia (860 μmol/L in blood cord) and nitisinone levels of 14 μmol/L. Following molecular confirmation of the diagnosis of HT1 specific treatment began on day 15 by which time she had detectable urinary succinylacetone.

In a series of 137 patients with methylmalonic acidaemia (MMA) and propionic acidaemia (PA) diagnosed since the early 1970s, we report in more detail 81 patients (51 MMA and 30 PA) diagnosed between 1988 and 2005. In this series, 14% of patients died at initial access revealing the disease before or despite treatment, 18% died later, and the remainder (68%) are still alive. All patients were treated with the same protocol of enteral feeds with a low-protein diet adjusted to individual tolerance, carnitine, antibiotics, and only occasional use of an amino acid (AA) mixture. There was intensive follow-up and monitoring using measurements of urinary urea. Thirty-nine patients with severe forms, followed for more than 3 years, are analysed in particular detail. Of the 17 PA patients, 6 had moderate disability (all neonatal-onset forms), whereas 11 were normal or slightly delayed in their mental development. Four presented with cardiomyopathy, of whom 2 died. Of the 22 MMA patients, 13 presented in the neonatal period, of whom 3 died later, 2 are in renal failure and only 5 are still alive and have a normal or slightly delayed mental development. In the 9 patients with late-onset forms, there were no deaths and all patients but one have normal mental development. Among the 39 patients, only 40% were given an AA supplement at 3 years, and 50% between 6 and 11 years. The actual intake of natural protein was 0.92, 0.78 and 0.77 g/kg per day at 3, 6 and 11 years, respectively, in patients without AA supplementation, whereas it was 0.75, 0.74 and 0.54 g/kg per day in the group who received small quantities of AA (0.4-0.6 g/kg per day). In both groups, feeding disorders were frequent: 55% at 3 years, 35% at 6 years and 12% at 11 years. Many patients were given a food supplement by tube overnight or were even exclusively tube fed: 60% at 3 years, 48% at 6 years and still 27% at 11 years. Growth velocity was near the normal values. Plasma valine and isoleucine were low to very low, as were leucine and phenylalanine but to a lesser extent. Albumin, vitamins, trace elements and markers of bone metabolism were within the normal values. IGF1, 24-hour urine calcium and body mass density were low. Body composition showed a normal to low lean mass and a normal to high fat mass.

Organic acidurias comprise many various disorders. Methylmalonic aciduria (MMA) and propionic aciduria (PA) are the most frequent diseases and the two organic acidurias for which we have better knowledge of the long-term outcome. Comparing the outcome of patients born before and after 1990, it appears that better neonatal and long-term management have improved the survival rate. Less than 20% of the patients died in either the neonatal period or before the age of 10 years. However, most surviving patients showed poor nutritional status with growth retardation and about 40% present some kind of visceral or neurological impairment. The developmental outcome may have improved in MMA patients, with IQ higher than 75 in about 40% patients aged more than 4 years. Conversely, poor intellectual development is the rule in PA patterns, with 60% having an IQ less than 75 and requiring special education. Successful liver and/or renal transplantations, in a few patients, have resulted in better quality of life but have not necessarily prevented neurological and various visceral complications. These results emphasize the need for permanent metabolic follow-up whatever the therapeutic strategy.

Branched chain organic acidurias are a group of disorders that result from an abnormality of specific enzymes involving the catabolism of branched chain amino acids (leucine, isoleucine, valine). Maple syrup urine disease (MSUD), isovaleric acidaemia (IVA), propionic aciduria (PA) and methylmalonic aciduria (MMA) represent the most commonly encountered abnormal organic acidurias. All these four disorders present in neonates as a neurologic distress of the intoxication type with either ketosis or ketoacidosis and hyperammonaemia. There is a free interval between birth and clinical symptoms. MMA, PA and IVA present with a severe dehydration, leuconeutropenia and thrombopenia which can mimic sepsis. All these disorders can be diagnosed by identifying acylcarnitine and other organic acid compounds in plasma and urine by gas chromatography mass spectrometry or tandem MS-MS. These disorders are amenable to treatment by removing toxic compounds and by using special diets and carnitine.

The cobalamin type C deficiency is a rare condition that results from impaired biosynthesis of both methylcobalamin (MeCbl) and adenosylcobalamin (AdoCbl). Hemizygous mutations of the HCFC1 gene explain the majority of clinically and biologically compatible cblC patients without MMACHC mutations (OMIM 309541). We report a family with two maternal half-brothers with multiple congenital anomalies and HCFC1 gene mutation in the second Kelch domain. Both presented with dysmorphic features (flat profile, cleft lip for one), increased nuchal translucency, prenatal onset microcephaly and hypospadias. Additionally to early onset intractable epilepsy and profound neurocognitive impairment, this familial observation suggests that HCFC1 gene should be considered in boys with midline malformations, even without proven cobalamin C deficiency.

A case of holocarboxylase synthetase (HCS) deficiency of late-infantile onset is presented and compared with the common manifestations in previously reported patients. Our patient had her first episode at 20 months followed by recurrent episodes of metabolic acidosis with ketolactic acidosis responding dramatically to a short trial of biotin and thiamin. The main clinical findings were metabolic acidosis with alteration in consciousness and respiration, which are in accordance with findings in earlier reported patients with both neonatal-onset and infantile-onset forms of HCS deficiency. The diagnosis of HCS deficiency was made only at the age of 5.5 years during a metabolic work-up when organic acid analysis was performed. This revealed elevated urinary excretion of the characteristics metabolites, 3-hydroxypropionate, 3-hydroxyisovalerate and methylcitrate, suggesting multiple carboxylase deficiency (MCD). MCD was demonstrated in fibroblasts of our patient, but only when the cells were grown in a medium with a very low biotin concentration of 10(-10) mol/L. Kinetics studies of reactivation of deficient propionyl-CoA carboxylase activity with biotin in intact fibroblasts revealed a midly decreased reactivation rate and only a 3-5 times higher biotin requirement as compared with controls. These findings are in accordance with a mild form of HCS deficiency. This child responded to 10 mg/day of biotin with normal lymphocyte carboxylase activities and adequate school performance at 10 years of age.

Primary persistent hyperinsulinaemic hypoglycaemia of infancy is rare. Diazoxide treatment remains the mainstay of medical therapy in long-term management. We reviewed 77 cases of primary persistent hyperinsulinism in neonates and infants who were treated with diazoxide and studied criteria predictive of therapeutic efficacy. The only criterion identified was age at manifestation. All but 1 of the 31 neonatal cases were unresponsive to diazoxide. Responsiveness increased with age: 12 of 39 early-infantile cases, and all seven late-infantile cases were diazoxide-responsive. In responders, a diazoxide dose of 10-15 mg/kg per day was always effective, suggesting an "all or none" response. Diazoxide-resistant hyperinsulinism is characterized by its severity with higher plasma insulin levels. The analysis of 46 surgically treated patients showed that the efficacy of diazoxide is not related to the aetiology of the pancreatic lesions. In six cases, after many years of management, diazoxide treatment was stopped without recurrence of hypoglycaemia. CONCLUSION: Diazoxide is an efficient treatment in the long-term management of most persistent hyperinsulinaemic hypoglycaemia of infancy revealed in infants and children but is usually ineffective in neonatal forms. Drug efficacy does not correlate with anatomical lesions. Medical treatment can sometimes be stopped after many years of management without recurrence of disease manifestations.

We report 8 cases of severe cytochrome c oxidase deficiency with onset in the neonatal period. Clinical symptoms were heterogeneous: antenatal cerebral malformations, neurological distress with ketoacidosis, severe myopathy, or isolated respiratory control failure. Lactic acid was elevated in blood and/or CSF in 7 cases. Muscle biopsy (7 patients), liver biopsy (4 patients), and cultured skin fibroblasts (7 patients) were used to assess the cytochrome c oxidase deficiency. Among the patients, the enzymatic defect differed in the level of residual activity, expression in different tissues and subunit composition in muscle (as analysed by immunohistochemistry). Southern blot analysis of the mitochondrial DNA was normal in 7 patients. The heterogeneity of cytochrome c oxidase deficiency was therefore demonstrated by these clinical presentations and by the biochemical assessment of the enzyme defect. This reflects, most probably, the diverse nature of the causal mutations.

We report our cumulative experience for the prenatal diagnosis of succinic semialdehyde dehydrogenase (SSADH) deficiency in seven 'at-risk' pregnancies from four unrelated families. Prenatal diagnosis was performed by determination of 4-hydroxybutyric acid (4-HBA) concentration in amniotic fluid using isotope-dilution gas chromatography-mass spectrometry in conjunction with assay of SSADH activity in biopsied chorionic villus and/or cultured amniocytes. In three of four pregnancies predicted as affected, confirmation was obtained by demonstration of deficient SSADH activity in fetal tissues. Our results suggest that determination of 4-HBA concentration in amniotic fluid combined with enzyme determination in cultured or biopsied tissue represents a reliable method for the prenatal diagnosis of SSADH deficiency.

MCAD deficiency is the most common fatty acid oxidation disorder, with the prevalence varying from 1/10,000 to 1/27,000 in the countries adjacent to France. As the High Authority for Health has recently proposed including MCAD deficiency in the panel of diseases neonatally screened for in France, a consensus was written for the management of MCAD deficiency diagnosed either clinically or by neonatal screening. Patients may present acutely with hyperammonemia, hypoglycemia, encephalopathy, and hepatomegaly, mainly after a prolonged fast of intercurrent infection. Sudden death related to heartbeat disorders may also occur. The diagnosis of MCAD deficiency is suspected on the plasma acylcarnitine and/or the urinary organic acid profile. The diagnosis is confirmed by molecular biology and the enzymatic activity for patients who are not homozygous for the main mutation c.985AG. However, some MCAD-deficient individuals may remain asymptomatic throughout life. The mainstay of treatment consists in avoiding prolonged fast and prescribing l-carnitine for patients who exhibit a deficiency in plasma carnitine. This management has radically modified the natural history of MCAD deficiency. This consensus will allow homogeneous management of these patients once the neonatal screening of MCAD deficiency has been introduced in France.

Sjögren-Larsson syndrome (SLS) is a neurocutaneous autosomal recessive disease caused by fatty aldehyde dehydrogenase (FADH) deficiency. This enzyme is involved in the biosynthesis pathways of some fatty acids, phytanic acid, and leukotrienes. The main features of the disease are its association with congenital ichthyosis, mental retardation, and spastic tetraplegia.We report on the diagnostic and therapeutic management of 2 cases of SLS.The diagnosis of SLS was suspected in the first patient at 2 years of age before the clinical triad appeared and confirmed at 4 years of age by the culture of fibroblasts and the peak of lipids on 1.3 ppm spectroscopy. After 3 months of treatment with zileuton, an inhibitor of leukotriene synthesis, moderate clinical efficacy for pruritus and ichthyosis was observed. The second patient was diagnosed at 1 year of age with the association of psychomotor retardation and congenital ichthyosis, in accordance with acute Guillain-Barré syndrome. Diagnosis was confirmed with enzymology, and cerebral spectro-MRI featured an abnormal lipidic peak. Zileuton therapy was initiated at the time of diagnosis and was effective for pruritus after 6 months of treatment.We report 2 cases of SLS with delayed diagnosis, due to non neonatal symptoms. Treatment with zileuton shows partial efficacy especially in pruritus. The uncommon association of this rare dysmyelinating disease with Guillain-Barré syndrome in the second patient is discussed.

Niemann-Pick type C disease (NPC) is a rare, neurovisceral, autosomic recessive, lysosomal lipid storage disorder associated with impaired intracellular lipid trafficking leading to accumulation of cholesterol and glycosphingolipids in the brain, the liver, the spleen and also the lung. NPC has a very heterogenous clinical presentation from perinatal period to adulthood. The perinatal presentation is visceral. In the early-infantile, late-infantile and juvenile period, a wide range of aspecific and progressive neurologic symptoms varies according to the age at onset, but four signs have a great diagnostic value : prolonged neonatal cholestasis, splenomegaly, cataplexy and vertical supranuclear gaze palsy. The diagnosis confirmation requires a fibroblast culture and molecular genetic testing of NPC1 and NPC2 genes. The recent approval of a specific treatment, reducing neurological disease progression, makes essential an early diagnosis of NPC.

The clinical and morphologic findings of three patients with metabolic acidosis, methylmalonic aciduria, and homocystinuria are presented. The clinical evolution of the patients was similar and was characterized in the first weeks of life by failure to thrive, hypotonia, and lethargy associated with pancytopenia and hepatic dysfunction, eventually progressing to severe respiratory insufficiency and renal failure consistent with a hemolytic-uremic syndrome. The patients died at 40, 45, and 75 days of age. Biochemical analyses and complementation studies revealed a congenital anomaly of vitamin B12 metabolism (cobalamin C disease). Postmortem morphologic findings in all three cases were dominated by a thrombotic microangiopathy of the kidneys and lungs, diffuse hepatic steatosis, and megaloblastic changes in the bone marrow. A severe gastritis with striking cystic dysplastic mucosal changes and total absence of parietal and chief cells was a consistent finding in all three cases, the rest of the gastrointestinal tract appearing essentially normal. Cobalamin C disease is an intracellular defect of cobalamin metabolism with possible recessive inheritance that can result in multiorgan failure early in life, with a thrombotic microangiopathy and unusual changes in the gastric mucosa.

Diabetes mellitus is occasionally observed in patients with skeletal muscle respiratory chain deficiency, suggesting that skeletal muscle mitochondrial dysfunction might play a pathogenic role in type 2 diabetes (T2D). In support of this hypothesis, decreased muscle mitochondrial activity has been reported in T2D patients and in mouse models of diabetes. However, recent work by several groups suggests that decreased muscle mitochondrial function may be a consequence rather than a cause of diabetes, since decreased mitochondrial function in mice affords protection from diabetes and obesity. We review the data on this controversial but important issue of potential links between mitochondrial dysfunction and diabetes.

Hyperargininaemia is a rare inborn error of metabolism due to a defect in the final step of the urea cycle. Infantile onset is the most common presentation with recurrent vomiting and psychomotor delay associated with spastic paraparesis; chronic hyperammonaemia is often overlooked. Neonatal and early-onset presentations are very uncommon and their clinical course not well-described. We report on a 3-week-old hyperargininaemic girl who presented with neurological deterioration associated with liver failure and 47-day ammonia intoxication before diagnosis could be made and treatment started. Despite appropriate but delayed treatment, our patient exhibited severe psychomotor delay at age 1 year. Conclusion Early identification and management of this rare but potentially treatable affection is crucial as delayed management may result in poor neurological outcome.

International audience; BACKGROUND: Cobalamin C disease is the most common inborn error of cobalamin metabolism with an autosomal recessive mode of inheritance and mutations within the MMACHC gene. Clinical features, including systemic, haematological and neurological abnormalities, usually occur in the first year of life. Adolescent and adult onset presentations are rare. METHODS: We report on the clinical, molecular and imaging features in three patients aged 40, 42 and 42 years at the last follow-up. We examine these cases together with eight previously described cases to determine the clinical and molecular features of the disease in adults. RESULTS: Mean age at onset of clinical symptoms was 26 years; clinical features included predominant neurological disturbances and thromboembolic complications. White matter abnormalities on brain MRI were sometimes observed. Most patients (eight of nine patients investigated) were compound heterozygotes for the 271dupA mutation and a missense mutation. Intramuscular or intravenous hydroxycobalamin therapy stopped the progression of the disease and resulted in a better clinical outcome and favourable biological status in 7/9 treated cases, while the two untreated patients died quickly. CONCLUSIONS: As cobalamin C disease and related disorders of homocysteine metabolism are treatable conditions, homocysteinaemia should be included in the investigations of patients with progressive neurological deterioration, unexplained psychiatric disturbances or recurrent thromboembolic events.

This paper describes MRI aspects of a leukodystrophy due to the Mitochondrial Neurogastrointestinal Encephalomyopathy syndrome in an adolescent girl investigated for nocturnal recurrent emesis leading to major cachexia.

Background Synonymous mutations within exons may cause aberrant splicing by disrupting exonic splicing enhancer (ESE) motifs in the vicinity of non consensus splice sites. Mutational analysis of PDHA1 revealed only one silent single nucleotide substitution in exon 5 in two unrelated boys and a girl (c.483C>T and c.498C>T variants, respectively). For both patients, pyruvate dehydrogenase complex activity was low and the immunoreactive E1alpha protein was defective in cultured fibroblasts. Methods and results One of the boys was a somatic mosaic for the c.483C>T variant, as shown by the variable ratio of mutant to normal alleles in fibroblast, lymphocyte and single hair root DNA. Transcript analysis in fibroblasts from the three patients revealed the presence of both normal and truncated cDNAs, with the splicing out of exon 5 predicted to result in a frame shift and premature termination (p.Arg141AlafsX11). The treatment of fibroblasts with emetine before harvesting to prevent nonsense mRNA-mediated decay increased the amount of mutant mRNA. In silico analysis revealed that each variant disrupted a putative SRp55 binding site and that the intron 5 donor splice site (5′ss) contained a weak splicing signal. Transient transfection of COS-7 or Hela cells with hybrid minigene constructs containing wild-type or mutant PDHA1 exon 5, followed by RT-PCR demonstrated that each variant resulted in the incomplete inclusion of PDHA1 exon 5, and that this defect was corrected following the restoration of a perfect consensus sequence for the 5′ splice site by site-directed mutagenesis. Conclusion These two synonymous mutations expand the spectrum of rare PDHA1 splicing mutations, all of which are located in non canonical splice sites.

We report on a 1-year-old boy, with carbohydrate-deficient glycoprotein (CDG) syndrome type I due to phosphomannomutase deficiency. Radiologic examination of the skeleton revealed previously unreported bone abnormalities that could be included in a dysostosis multiplex: wide ribs, squared iliac wings, horizontal acetabular roofs, widening and modeling abnormalities of ischial and pubic bones, dorsolumbar kyphosis, and slight hook-like dysplasia of the first lumbar vertebrae. Wormian bones were also present. We suggest that these features may be due to hypoglycosylation of bone proteins and that CDG syndrome type I should be included in the differential diagnosis of dysostosis multiplex.

Thiamin deficiency can lead to various clinical presentations, such as classical beriberi, Wernicke's encephalopathy, acute thiamin deficiency syndrome (ATD) and cardiovascular shock (Nakasaki et al 1997; Remond et al 1999; Romanski and MacMahon 1999; Svahn et al 2003). Characteristics of total parenteral nutrition (TPN)-induced ATD include a history of TPN with 10-30 days without vitamin supplementation, severe lactic acidosis refractory to massive doses of bicarbonate, α-ketoacid accumulation in plasma and urine, resolution of clinical and metabolic features within a few hours following the injection of thiamin, and rapid progression of the disease and fatal outcome without thiamin supplementation. The diagnosis can be confirmed by demonstrating a low thiamin concentration in a total blood sample (Kitamura et al 1996). To date, only two cases of ATD during TPN in the neonatal period have been reported (Matern et al 1996). Here, we report on a series of 11 neonates with strongly suspected or confirmed severe lactic acidosis related to ATD during TPN, collected from 1973 to 2001 following a French collaborative study (Table 1). The ages of the patients ranged from birth to 3.5 months of life. In all cases, the underlying disease for which TPN was investigated was bowel intolerance or malformation. There were no features of primary haemodymamic or septic distress. Clinical features appeared from 11 to 29 days (average = 17.8 days) after the beginning of TPN without thiamin supplementation (or after the end of thiamin supplementation), and included tachypnoea, hypotension, tachycardia, haemodynamic distress, vomiting, agitation, hypotonia and lethargy. Only one patient did not present anv clinical features during the 7-day period of thiamin deficiency-related lactic acidosis.

Phenylketonuria (PKU) is an inherited metabolic disease affecting about one birth out of 15 000. From 1978, a national systematic neonatal screening was set up in France with a regional organisation. French rational and guidelines have been established by the national PKU group with the collaboration of all the physicians responsible for the regional centres. These guidelines specify the minimal diagnosis procedures leading to an optimal treatment of all patients. A low-phenylalanine diet must be started as soon as possible in the neonatal period for all newborns whose phenylalanine levels are above 10 mg/dl. The dietary control must keep the phenylalanine plasma levels between 2 and 5 mg/dl until 10 years of age. After this age, several data argue for a progressive and controlled relaxation of the diet, keeping the phenylalanine level below 15 mg/dl until the end of the adolescence and below 20 to 25 mg/dl in adulthood. All PKU patients must be followed up for life, in order to screen those who may not bear the diet relaxation and in order to strictly prevent maternal PKU deleterious consequences.

The authors report 7 years of follow-up evaluation of a patient with coenzyme Q 10 (CoQ 10 ) deficiency. Initial symptoms of exercise intolerance and hyperlactatemia improved markedly with substitutive treatment. However, CoQ 10 supplementation did not prevent the onset of a cerebellar syndrome. A switch to idebenone treatment resulted in clinical and metabolic worsening, which disappeared with subsequent CoQ 10 treatment. CoQ 10 defects may cause progressive neurologic disease despite supplementation.

Congenital disorders of glycosylation type I (GDG-I) is a class of genetic multisystem disorders characterised by defective glycosylation of glycoproteins. The characteristics and mechanisms of failure to thrive and intestinal diseases present in CDG-I are anectodal.The aim of this study was to analyse 7 CDG-I (4 CDG-Ia, 2 CDG-Ib and 1 CDG-Ix) with important digestive symptoms and failure to thrive in order to characterise the mechanisms implied.Four children had no skin abnormality or dysmorphia (1 CDG-Ia, 2 CDG-Ib, 1 CDG-Ix). An encephalopathy with cerebellar hypoplasia was present only in the 4 CDG-Ia. Failure to thrive and diarrhea were present during the first month of life in 6 and appeared at 5 years in one CDG-Ia associated to mild or severe hepatopathy in all patients. One CDG-Ia, 1 CDG-Ib, 1 CDG-Ix had an exsudative enteropathy. A positive steatorrhea was present in 3 patients. Five patients had an abnormal small bowel biopsy. Abnormalities were variable: moderate inflammation of the chorion without villous atrophy in 2, intra-enterocyte fat accumulation without villous atrophy in 2, and partial villous atrophy with lymphangectasia in 1. In 2 CDG-Ia the intestinal biopsy was normal. Enteral nutrition in 4 and parenteral nutrition in 2 were effective in 4 patients and 1 patient with an exsudative enteropathy respond to a free fat diet (CDG-Ix).The digestive symptoms with failure to thrive is a common feature of CDG-I and could be the first symptoms. The diagnostic should be suspected if no other cause is found. Mechanisms of the intestinal symptoms appear to be multiple such as inflammation, abnormal enterocyte lipid transport or intestinal permeability related to the abnormal glycosylation of intestinal mucosa glycoproteins.

Through a report of 4 late-onset cases with mitochondrial DNA (mtDNA) depletion, we address the specificity of the clinical entities associated with a very low residual amount of mtDNA. Three of the patients met the diagnostic criteria of Kearns Sayre syndrome, which has never been associated with mtDNA depletion. The fourth patient had an isolated skeletal myopathy. Deleted mtDNA molecules were found by long-range polymerase chain reaction (PCR) only in the Kearns Sayre syndromes, which strengthens the clinical differences between the two types of patients. All patients had extremely low residual amounts of mtDNA as shown by Southern blot analysis. Using an original method based on competitive PCR, we were able to measure the number of mtDNA copies per diploid genome. These results demonstrated the severity of the depletion in the patients by comparison not only to normal controls but also to patients with mtDNA disorders. Despite the severity of the depletion, in situ hybridization using two mtDNA transcripts revealed a normal steady-state level of transcription. Such compensation provides clues to the striking contrast between the severity of mtDNA depletion and the late onset and slowly progressive disease.

Hereditary tyrosinemia type I is a disease with a severe prognosis. Main causes of death are acute liver failure, neurologic crises and hepatocarcinoma. NTBC, which acts as an inhibitor of the 4-hydroxyphenylpyruvate dioxygenase, prevents the formation of toxic metabolites involved in hepatic, renal and neurologic lesions.Results of NTBC therapy used in three infants with type I tyrosinemia who presented with acute liver failure are reported. The diagnosis relied on the finding of high plasmatic levels of tyrosine and methionine, and abnormal urinary excretion of succinyl acetone and delta aminolevulinic acid. Treatment with NTBC was initiated within 2 to 8 days from onset of symptoms. Signs of liver failure resolved after 3 weeks therapy. After 12 to 39 months of follow-up, outcome remains favorable.The results reported here highlight the efficiency of NTBC in type I tyrosinemia with early acute onset. However, the long term outcome needs to be determined with regards to prevention of hepatocarcinoma and toxicity of the drug.

The age of discovery and initial symptoms of cow milk allergy can vary. Lactic acidosis is exceptionally associated to this allergy.A 32-day-old girl was admitted for a severe malaise with metabolic acidosis and hyperlactacidemia. There were no neonatal or family problems; breastfeeding was stopped on the 25th day. Fever was noted on the 29th day and her mother reported behavior anomalies followed by a severe malaise with unconsciousness between the 29th and 32nd day. At admission, the infant showed a severe neurological distress, hypotonia and lethargy. Infection and neurological imaging were normal. A compensated metabolic acidosis with hyperlactacidemia (5.96 mmol/L) was noted. There was no argument for esophageal reflux nor vagal hypertony; mitochondrial cytopathy was also excluded. After a 24 hours fast, the clinical state gradually improved and normalized at h48. The infant was discharged with a milk protein hydrolysate formula. Her mother attempted to reintroduce cow milk on the 59th and 64th day, but this was immediately followed by allergic manifestations which supported the diagnosis of cow milk allergy.Neurological distress and hyperlactacidemia exceptionally reveal this type of intolerance. The mechanism of hyperlactacidemia remains unclear; it is possibly the consequence of severe changes of the intestinal mucosa, an exclusive glycolytic tissue.

We report a case of a large blue mongolian spot which led to early diagnosis of Hurler's syndrome. This association is uncommon and should be recognized by dermatologists for early diagnosis and management.A male infant from Guinea, born to first-cousin parents, was seen at the age of 4.5 months for multiple, particularly extensive blue mongolian spots. Growth was +2 SD for age and the infant's psychomotor development was normal. A slight thickening of the skin was noticed without real dysmorphism. The blue spots extended over the entire posterior aspect and part of the anterior aspect of the trunk and involved all four limbs and the eyelids. The elbow and knee joints were moderately stiff and liver enlargement was palpated. The skin biopsy showed fusiform cells with melanin pigment tattooing the cytoplasm. No vacuolized epidermal cells were observed. Blood cell counts and liver and kidney tests were normal. Tests were positive for vacuolized lymphocytes and Gasser lymphocytes. Urine was positive for mucopolysaccharides and the enzymology study showed an alpha-L-iduronidase deficiency in serum and leukocytes, confirming the diagnosis of Hurler's disease. As no HLA compatible donor was available, no bone marrow graft was attempted. The child is a candidate for organoid gene therapy.Mongolian spots predominate in Asian, American Indian and black population (90% of the cases) compared with Caucasians (10%). The pathogenesis and pathogenic associations are unknown. The incidence of large widespread mongolian spots is also unknown and no precise criteria are available to define this entity. A few cases of extended mongolian spots associated with type 1 gangliosidosis and about 20 cases associated with Hurler's disease have been reported in the literature. The association with Hurler's disease is probably not fortuitous and several hypotheses have been put forward. Bone marrow transplantation can improve prognosis if performed early before onset of irreversible visceral disorders, emphasizing the importance of early diagnosis in children.

OBJECTIVE To assess the prevalence of in vivo detectable abnormalities of lactate metabolism in mitochondrial disorders. DESIGN Retrospective study in a metabolic investigation unit. PATIENTS 28 patients with a respiratory chain disorder identified from biochemical or genetic analyses, or both, and 133 age matched controls. Controls were children in whom causes of secondary hyperlactataemia and/or disorders, affecting the energy pathways could be excluded. METHODS Lactate and pyruvate were measured in blood, together with other intermediary metabolism indices, before and one hour after four meals each day. Lactate and creatinine in a 24 hour urine sample collected at the same time were analysed. When basal hyperlactataemia was not evident, an intravenous glucose or pyruvate loading test was performed as a provocative test. RESULTS Abnormal lactate metabolism was found in 25 of 28 patients thus demonstrating the potential usefulness of these investigations in the diagnosis of mitochondrial diseases. Moderate lactate accumulation was present in relatively mild disease, associated with a mitochondrial DNA mutation and combined respiratory complexes deficiency. By contrast, high lactate concentrations were observed in very young children, with severe disease, isolated complex deficiency, and no apparent mitochondrial DNA defect.

The marrows of patients with lysinuric protein intolerance (LPI) are generally considered as normal, even though autoerythrophagocytosis has been observed in some of them.Lysinuric protein intolerance was recognized in two 12 and 15-year-old brothers who had been diagnosed following an immuno-hematological investigation. Clinical history had been characterized by a neonatal macrophage activation syndrome (hepatosplenomegaly, pancytopenia, hypofibrinogenemia and hypertriglyceridemia). A putative diagnosis of familial lymphohistiocytosis had been ruled out because of unusual clinical and immunological course. Both brothers had displayed chronic aversion to high-protein foods, failure to thrive, osteoporosis and developmental delay. Metabolic investigations had revealed chronic hyperammonemia while cationic aminoaciduria (lysine, arginine and ornithine) was only present during L-citrulline supplementation. Bone marrow examinations had been performed during the neonatal period and during later metabolic investigations. They both displayed a peculiar red cell and granulocytes phagocytosis by histiocytes and granulocytes precursors.This aspect of bone marrow could be considered as a specific sign of LPI. This report suggests that appropriate metabolic investigations should be performed in any unexplained macrophage activation syndrome.

Pregnant women with hyperphenylalaninemia are at high risk of spontaneous abortion and of giving birth to infants with congenital malformations, microcephaly and mental defect. Among mothers whose phenylalaninemia is greater than 1200 mumol/L (20 mg/100 mL), 95% have at least one child with mental retardation. A low phenylalanine diet with a good control of phenylalaninemia, started before conception, reduces this risk, better results being obtained when plasma phenylalanine levels are maintained below 360 mumol/L (6 mg/100 mL) as compared with levels maintained between 360 to 600 mumol/L (6-10 mg/100 mL). Thus, systematic contraception and planned pregnancies must be recommended in all hyperphenylalanemic young women. This implies early information of phenylketonuric teenage girls and their parents. In addition, efforts must be made to join and inform all women having had hyperphenylalaninemia at birth, whether they received a dietary treatment or not. It is also important that general practitioners, pediatricians and obstetricians be aware of the high recurrence risk in hyperphenylalanemic women who gave birth to a microcephalic or malformed infant.

A retrospective study was performed on the clinical outcome and long-term treatment of 17 patients with propionic acidaemia diagnosed during the last 20 years in our hospital. The study group consisted of 12 patients with early onset type of disease and 5 patients with late onset. Seven (41%) patients died, five with early onset and two with late onset. The deceased early onset patients had a median survival of 0.4 years while the deceased late onset patients died at the age of 2.8 and 4 years respectively. Median age of the living early onset patients was 5.2 (1-9.25) years, the late onset patients were 4, 7 and 23 years old. Patients were all treated with natural protein restriction and in most cases carnitine and metronidazole were added. The early onset patients were almost all treated with daily home tube feeding. The mean natural protein intake of early onset patients (6.3 +/- 1.5 g/day) was significantly lower than the natural protein intake of late onset patients (17.6 +/- 5.3 g/day). Supplemental protein intake was higher in early onset patients. The general neurological outcome of our study group was satisfactory with a better outcome for early onset patients. As to growth, many patients showed a failure to thrive, this was particularly for height. The strong protein restriction during the first years of life probably contributed to this.The prognosis for patients with propionic acidaemia appeared to be satisfactory in terms of survival and outcome characteristics such as neurological and mental development. Despite these results the authors feel that the prognosis and quality of life of these patients might be improved with liver transplantation or possibly somatic gene therapy in the future.

This paper underscores the contribution of routine morphological examination of skeletal muscle in patients with lactic acidosis. Mitochondrial disorders are by far the most common causes of primary lactic acidosis, in which muscle biopsy analysis helps in diagnosis and in the search for the molecular anomalies. Thus, we focus our attention on one particular point: the contribution of the morphological study of muscle biopsy in primary lactic acidosis due to mitochondrial disorders, especially mitochondrial respiratory-chain diseases.

Carnitine-acylcarnitine translocase deficiency is a newly recognized inborn error of metabolism that involves transport of long-chain fatty acids into mitochondria, which in turn impairs mitochondrial beta-oxidation, and ketogenesis. We report a new familial example; the affected twins had neonatal distress, hyperammonemia, and transient intracardiac conduction defects. Clinical and biochemical analysis of both our patients and the two previously reported patients revealed that this inherited defect could be manifested during the neonatal period without any of the signs classically associated with fatty oxidation defects. In contrast, all four patients had sustained and "isolated" hyperammonemia, which could be misinterpreted as being caused by urea cycle defects. We conclude that carnitine-acylcarnitine translocase deficiency is a potential differential diagnosis in neonates with unexplained neonatal hyperammonemia. Cardiac and muscle involvement may represent further early pivotal symptoms.

Dietary treatment of maple syrup urine disease remains difficult; chronic nutritional support in the child does not always avoid acute crises so that liver transplantation may represent an alternate choice in some cases.Two gypsy cousins were born by an interval of 4 days; both had maple syrup urine disease and were similarly treated from the first days of life. They were given exchange transfusions followed by diet restricted in the branched chain amino acids, maintaining normal growth and plasma leucine concentrations under 7 mg/100 ml. Laura, at 10 years, was retarded at school. Compliance to school attendance was limited by her diet problems. Helen suffered at 7 yr 3 mo from liver failure due to hepatitis A virus infection which required liver transplantation. Protein intake was normal 1 week later. At 10 years, she presented with the same degree of school retardation as her cousin, and was placed in the same class.Liver transplantation may be effective for treating metabolic problems in MSVD without significative difference between outcome post classic treatment or post liver transplantation.

A hemolytic-uremic syndrome associated with methylmalonic aciduria and homocystinuria is seen during the first weeks of life. A molecular defect in the CbIC mutation has been found. This report describes a new case with this association.A girl, the second in this family, was born at term: her birth weight was 2,100 g, height was 47 cm and head circumference 31.5 cm. She was admitted at 32 days of age with hemolytic anemia and fragmencytosis, renal failure and thrombocytopenia. The renal failure required peritoneal dialysis followed by hemofiltration. The signs of pancytopenia of central origin and liver failure seen at that time raised the possibility of an intracellular defect of B12 metabolism. Chromatography of the amino acids and organic acids in the urine and plasma revealed homocystinemia, hypomethioninemia, homocystinuria and methylmalonic aciduria. The deficient B12 metabolism was confirmed in fibroblasts which showed deficits in both methyl and adenosyl-cobalamin synthesis. The metabolic disturbances were completely resolved after intravenous administration of hydroxy-cobalamin (2,000 micrograms per day) and folinic acid (25 mg per day) for 5 days. But the neurological abnormalities persisted, with retinitis pigmentosa and major leukodystrophic changes seen by MRI, and the infant died one month later.This new case emphasizes the importance of systematically screening all cases of neonatal hemolytic-uremic syndrome for this autosomal recessive disorder.

Two brothers, aged 27 and 20 months, born from consanguineous healthy parents, presented with cardiomyopathy, lactic acidosis and carnitine abnormalities in serum and muscle, without clinical evidence of muscle involvement. The histochemical reaction for cytochrome c oxidase (COX) activity was negative in all muscle fibres, although the holoenzyme and subunits were present at a normal level, as shown by immunocytochemistry. The COX activity was, respectively, 5 and 25% of control values, in muscle biopsies. Partial deficiency of complex IV was confirmed in fresh isolated muscle mitochondria from patient 2 and was associated with a defect of complex I. Patient 1 died at age 3 yr 6 months. Partial improvement of cardiomyopathy in patient 2 was obtained under carnitine therapy, but seizures occurred and CT scan and magnetic resonance imaging (MRI) revealed thalamic hypodensity. Thus, the disorder appears to be progressive despite the clinical stabilization of the cardiomyopathy. This further demonstrates the complexity and clinical heterogeneity of combined respiratory chain complex deficiencies.

We describe two asymptomatic newborns with nutritional vitamin B12 deficiency in whom increased urinary methylmalonic acid was detected by routine neonatal screening at 3 weeks of age. Both infants were exclusively breast-fed. One mother suffered from pernicious anaemia, and the other was a strict vegetarian. Both mothers had no clinical or haematological abnormality, aside from a borderline mean corpuscular volume for the vegetarian mother. This report illustrates the early appearance of functional vitamin B12 deficiency in breast-fed infants of vitamin B12-depleted mothers. It also demonstrates that urinary methylmalonic acid measurement is a sensitive indicator of tissue vitamin B12 deficiency.

A case of combined deficiency of sulphite-oxidase and xanthine-oxidase with a defect of the molybdenum cofactor, which is vital to the activity of sulphite-, xanthine- and aldehyde-oxidase, is reported here. Seven cases of combined deficiencies have been described with regard to both clinical and laboratory findings. The clinical, laboratory and anatomo-pathological features and, in particular, the central nervous system lesions of the present case correspond exactly to those in the case described Rosenblum in which an isolated deficiency in sulphite-oxidase was present. As the cerebral alterations in the present case are comparable to those described in Rosenblum's case, they probably result from the defect in sulphite-oxidase activity.

We describe a patient with severe muscle cytochrome c oxidase deficiency who had de Toni-Fanconi-Debre syndrome and acute neurologic deterioration resembling Leigh syndrome, without clear evidence of muscle abnormality. Metabolic investigations revealed elevated cerebrospinal fluid lactate values contrasting with normal blood lactate, and high 3-hydroxybutyrate/acetoacetate ratio with normal lactate/pyruvate ratio. This case emphasizes the importance of performing metabolic and biochemical investigations in every patient with Leight syndrome, even in the absence of hyperlactatemia or myopathy.

Peroxisomes were visualized by cytochemical staining for catalase or/and electron microscopy in liver biopsies of two boys with childhood adrenoleukodystrophy (ALD), and of two girls with autopsy confirmed neonatal adrenoleukodystrophy (NALD). In a third patient previously described as NALD, unusual organelles were seen which may be large abnormal microbodies. Enlarged peroxisomes (determined by morphometry) were also present in the livers of the other two NALD patients. In the ALD patient whose clinical disease was more severe, peroxisomes were larger than in the older ALD case. Catalase staining was diminished and markedly heterogeneous. Additional unusual features such as a separate population of tubular forms, contact with fat droplets, of tubular forms, contact with fat droplets, marginal plate and invaginations containing glycogen were seen in the neonatal cases. These data are compared to the enlarged or elongated peroxisomes and heterogeneous staining in the thiolase-deficient "pseudo-Zellweger" patient (Goldfischer et al. 1986) and in 2 siblings with acylCoA oxidase deficiency (Poll-Thé et al. 1986, 1988). Enlarged peroxisomes are a common feature in this group of patients with peroxisomal deficiency disorders, suggesting that increased size and lowered metabolic capacity are associated. Nevertheless a marked morphopathological heterogeneity of peroxisomes thus exists in syndromes described as NALD including previously published cases. Most likely this heterogeneity reflects different enzymatic deficiencies, as confirmed by the biochemical data available. Clinically similar syndromes cover divergent microscopical and enzymatic peroxisomal patterns, and naming of the disease should be adapted to reflect such data. Cytochemical studies are urged in every suspected patient.

Infantile Refsum's disease was diagnosed in three male patients, presenting with facial dysmorphia, retinitis pigmentosa, neurosensory hearing loss, hepatomegaly, osteopenia and delayed growth and psychomotor development. An elevated plasma phytanic acid concentration and a deficient phytanic acid oxidase activity in fibroblasts were found with an accumulation of very long chain fatty acids in plasma and fibroblasts. There were elevated pipecolic acid levels in plasma, urine and CSF, and abnormal bile acid metabolites in plasma. Deficient activity of acylCoA: dihydroxyacetone phosphate acyl transferase was found in thrombocytes and fibroblasts of these patients as well as an impaired de novo plasmalogen biosynthesis in fibroblasts. These biochemical abnormalities, previously described in the Zellweger syndrome, suggest multiple peroxisomal dysfunction in our patients.