PubMed Health⌕ Search

Biomedical subjects

P G Barth

Publications and source records attributed to P G Barth.

At least 37 records · Page 2Linked to original sources
PubMed2000

[Spina bifida: prevention policy can be more effective].

The prevalence of the severe disease spina bifida is decreasing, but the present rate is still unacceptably high. Only one-third of women planning motherhood use the recommended folic acid, although compliance is increasing. Campaigns for the use of folic acid by these women should be intensified. This method, however, cannot completely prevent the occurrence of spina bifida. A further reduction is possible by using ultrasound screening in the second trimester of pregnancy. Therefore this option of secondary prevention should be studied as soon as possible.

Adult↗
PubMed2000

[Sensitive and specific screening for detection of spina bifida by echography in the second trimester; systematic review and meta-analysis].

OBJECTIVE: Evaluation of the diagnostic accuracy of ultrasound in the second trimester for the detection of spina bifida. DESIGN: Systematic review and meta-analysis. METHOD: Medline and Embase were searched to identify prospective studies in a general pregnant population. Also, in the Cochrane Library, references of identified reports and recent reviews were checked for relevant studies. Retrieved abstracts were selected independently by 2 authors using predefined criteria. Assessment of quality and generalizability of the included studies and data extraction were performed by 3 authors independently. The data were tested for heterogeneity and pooled estimates of sensitivity and specificity were calculated for all studies. RESULTS: 13 studies were included. Specificity was approximately 100% in all cases. Sensitivity varied from 40% to 100%. The summary point estimate for sensitivity was 71% with a 95% confidence interval of 59%-81%. CONCLUSION: Ultrasound in the second trimester is a specific investigation to detect spina bifida, which may detect seven out of ten defects. Used as a screening tool, it could contribute to a significant reduction in the number of children born with spina bifida.

Female↗
PubMed2000

Sarcoglycanopathies in Dutch patients with autosomal recessive limb girdle muscular dystrophy.

Within a group of 76 sporadic/autosomal recessive limb girdle muscular dystrophy (LGMD) patients we tried to identify those with LGMD type 2C-E. Muscle biopsy specimens of 40 index patients, who had 22 affected sibs, were analyzed immuno-histochemically for the presence of three subunits: alpha-, beta-, and gamma-sarcoglycans. Abnormal sarcoglycan expression was established in eight patients, with six affected sibs. In one patient gamma-sarcoglycan was absent, and both alpha- and beta-sarcoglycans were reduced. In the remaining seven patients gamma-sarcoglycan was (slightly) reduced, and alpha- and beta-sarcoglycans were absent or reduced. By DNA sequencing mutations were detected in one of the three sarcoglycan genes in all eight cases. Three patients had mutations in the alpha-, three in the beta-, and two in the gamma-sarcoglycan gene. The patients with sarcoglycanopathy comprised the more severely affected cases (P=0.04). In conclusion, sarcoglycanopathy was identified in 23 % (14/62) of the autosomal recessive LGMD patients.

Adolescent↗
PubMed2000

Pontocerebellar hypoplasia--how many types?

An original article describes a sibship with early fatal pontocerebellar hypoplasia of a yet unclassified type, with the accompanying features of polyhydramnios and neonatal myoclonus. Autopsy in one patient excluded spinal anterior horn involvement, which argues against pontocerebellar hypoplasia type I (PCH-1). The present PCH classification and literature are briefly reviewed. Four previous publications bear similarity to the present report. Definite classification as a genetically separate entity, however, remains elusive pending localization and identification of the gene(s) involved.

Brain Diseases↗
PubMed2000

Carbohydrate-deficient glycoprotein syndrome type 1a: a variant phenotype with borderline cognitive dysfunction, cerebellar hypoplasia, and coagulation disturbances.

An 8-year-old boy is described with borderline cognitive impairment, cerebellar hypoplasia, a stroke-like episode, and venous thrombosis of the left leg after a period of immobilization. The pattern of multiple abnormalities in blood coagulation suggested carbohydrate-deficient glycoprotein syndrome type 1a. Isoelectric focusing of serum transferrin was abnormal. The activity of phosphomannomutase in leukocytes and fibroblasts was decreased. Mutation analysis of the PMM2 gene revealed the R141H/E151G genotype. These results confirm the presence of carbohydrate-deficient glycoprotein syndrome type 1a without severe psychomotor retardation.

Blood Coagulation Disorders↗
PubMed1999

Functional heterogeneity of C-terminal peroxisome targeting signal 1 in PEX5-defective patients.

To investigate mechanisms related to functions of the peroxisome targeting signal (PTS) 1 receptor, Pex5p, we analyzed peroxisome matrix protein import in fibroblasts from three patients with peroxisome biogenesis disorders, all with different mutations in the PEX5 gene. The patients 2-01 (Zellweger syndrome) and 2-05 (neonatal adrenoleukodystrophy) have the reported mutations, R390X and N489K, and patient 2-03 (infantile Refsum disease) has a newly identified mutation, S563W. Fibroblasts from 2-03 (S563W) were detected in both PTS1 and PTS2 imports despite the PEX5 defect, findings in contrast with fibroblasts from 2-05 (N489K) severely defective in PTS1 import and those from 2-01 (R390X) severely defective in both PTS1 and PTS2. The PTS1 receptor in 2-03 is functional for only the C-terminal -SKL sequence (acyl-CoA oxidase) and had little or no function for C-terminal -AKL (D-bifunctional protein and sterol carrier protein 2) and -KANL (catalase) sequences, respectively. After transfection of these mutated PEX5 cDNA into the PEX5-defective CHO mutant, transformants of ZP102 revealed that each mutation was responsible for each dysfunction of the PTS1 import. It seems apparent that -AKL and -KANL are poorer variants of PTS1 and are likely to be more susceptible to effects of mutation of its receptor, Pex5p.

17-Hydroxysteroid Dehydrogenases↗
PubMed1999

Genomic structure and identification of 11 novel mutations of the PEX6 (peroxisome assembly factor-2) gene in patients with peroxisome biogenesis disorders.

The PEX6 (peroxisome assembly factor-2, PAF-2) gene encodes a member of the AAA protein (ATPases associated with diverse cellular activities) family and restores peroxisome assembly in fibroblasts from peroxisome biogenesis disorder patients belonging to complementation group C (group 4 in the United States). We have now clarified the genomic DNA structure of human PEX6 and identified mutations in patients from various ethnic groups. The human PEX6 gene consists of 17 exons and 16 introns, spanning about 14kb. The largest exon, exon 1, has at least 952 bp nucleotides. Eleven novel mutations (18 alleles) were identified by direct sequencing of the PEX6 cDNA from 10 patients. All these mutations have been confirmed in the corresponding genomic DNA. There was no common mutation, but an exon skip was identified in two unrelated Japanese patients. Most of the mutations led to premature termination or large deletions of the PEX6 protein and resulted in the most severe peroxisome biogenesis disorder phenotype of Zellweger syndrome. A patient with an atypical Zellweger syndrome had a missense mutation that was shown to disrupt the cell's ability to form peroxisomes. This mutation analysis will aid in understanding the functions of the PEX6 protein in peroxisomal biogenesis. Hum Mutat 13:487-496, 1999.

ATPases Associated with Diverse Cellular Activitie↗
PubMed1999

Leigh syndrome associated with a mutation in the NDUFS7 (PSST) nuclear encoded subunit of complex I.

Leigh syndrome is the phenotypical expression of a genetically heterogeneous cluster of disorders, with pyruvate dehydrogenase complex deficiency and respiratory chain disorders as the main biochemical causes. We report the first missense mutation within the nuclear encoded complex I subunit, NDUFS7, in 2 siblings with neuropathologically proven complex I-deficient Leigh syndrome.

Humans↗
PubMed1999

Aicardi-Goutières syndrome: a genetic microangiopathy?

Aicardi-Goutieres syndrome (AGS) (McKusick 225750) is an autosomal recessive disease with onset in the 1st year of life, resulting in progressive microcephaly, calcification of cerebral white matter, thalamus and basal ganglia, generalized cerebral demyelination and a chronic low-grade CSF lymphocytosis, without evidence of infection. We report the autopsy of a patient who died with this disorder at the age of 17 years. Findings were severe microencephaly, diffuse but inhomogeneous cerebral white matter loss with associated astrocytosis, calcific deposits in the white matter, thalami and basal ganglia. Neocortex and cerebellar cortex were affected by wedge-shaped microinfarctions. Small vessels showed calcification in the media, adventitia and perivascular spaces. These findings are similar to some previous publications that in retrospect may have been AGS, but this is the first reported cerebral microangiopathy in which the diagnosis AGS was made during lifetime. This report provides evidence that microangiopathy plays a significant role in the pathogenesis of AGS.

Adolescent↗
PubMed1999

Cerebral palsy and pyruvate dehydrogenase deficiency: identification of two new mutations in the E1alpha gene.

UNLABELLED: Pyruvate dehydrogenase (PDH) complex deficiency, a common cause of congenital lactic acidosis, is mostly due to mutations in the X-linked gene coding for the E1alpha subunit of the complex. We have studied two unrelated girls presenting a static encephalopathy with spastic quadriplegia, microcephaly and seizures and in one girl, hypocalcaemia, a new finding in PDH complex deficiency. PDH deficiency was diagnosed in adolescence and both girls had low PDH complex activity in muscle but normal amounts of all subunits on Western blotting, and a normal lactate/pyruvate ratio in blood and CSF. Mutation analysis of the E1alpha gene at the cDNA or DNA level revealed an arginine to histidine substitution at amino acid position 288 (R288H) in the girl with hypocalcaemia and a 12 bp insertion, predicting a four amino acid duplication at the c-terminal end of the protein in the second girl. They both carried a normal and a mutated E1alpha gene and X-inactivation studies showed skewed patterns. CONCLUSION: Mutation identification in pyruvate dehydrogenase complex deficiency remains important especially for the determination of the recurrence risk and for reliable genetic counselling in couples with an affected child.

Acidosis, Lactic↗
PubMed1999

X-linked cardioskeletal myopathy and neutropenia (Barth syndrome) (MIM 302060).

X-linked cardioskeletal myopathy, neutropenia and abnormal mitochondria (MIM 302060) (synonyms: Barth syndrome, 3-methylglutaconic acid-uria type II, endocardial fibroelastosis type 2) has been reported in patients and families from Europe, North America and Australia. Previous studies characterized the main components of the disease: dilated cardiomyopathy, skeletal myopathy, neutropenia, 3-methylglutaconic aciduria and diminished statural growth. Respiratory chain impairments have been found in several studies, without pinpointing a single enzyme complex. 3-Methylglutaconic aciduria is shared with several other disorders that affect the respiratory chain. Previous studies excluded a block in the major pathway of leucine catabolism. We performed leucine loading, accompanied by fasting, in patients and observed a significant rise of 3-methylglutaconic acid and 3-methylglutaric acid. Taken together with the absence of an enzymatic block in the major leucine catabolic route, the possibility remains that the increased basal excretion of 3-methylglutaconic acid and other products of branched-chain amino acids is the result of overload of this pathway or--more likely--mitochondrial leakage. Linkage studies have localized the gene to the Xq28 region. The associated tafazzin gene (TAZ), has been fully characterized recently, and mutations located in conserved regions have been reported. Carrier detection and prenatal diagnosis have now become possible through mutation analysis. Sequence homology of the TAZ gene to a highly conserved superclass of acyltransferases (Neuwald's hypothesis) predicts a glycerophospholipid as the missing end product. This points to the (lipid) structure of the inner mitochondrial membrane as a promising new area of research.

Cardiomyopathy, Dilated↗
PubMed1999

Subependymal nodular heterotopia in patients with encephalocele.

Only incidental mention has been made to date of the combined occurrence of subependymal heterotopia and posterior encephalocele. We evaluated the presence of disseminated nodular subependymal heterotopia in two series of patients with posterior encephalocele. The first series consisted of all six patients who were treated in our hospital for encephalocele during the last 11 years and who underwent magnetic resonance imaging (MRI). In three, subependymal nodular heterotopia was found by MRI. The second series consisted of eight autopsy cases with encephalocele, representing all cases of encephalocele that came to autopsy during a 10-year period on whom full microscopic examination could be performed. Nodular heterotopia was found in four. The combined occurrence of these two rare conditions may not be accidental.

Brain Diseases↗
PubMed1999

Pontocerebellar hypoplasia associated with respiratory-chain defects.

Pontocerebellar hypoplasias are congenital disorders of brain morphogenesis which include such diverse etiologies as carbohydrate-deficient glycoprotein syndrome type 1, cerebromuscular dystrophies (Walker-Warburg syndrome, Fukuyama syndrome, muscle-eye-brain disease) and at least two types of autosomal recessive neurodegenerations known as pontocerebellar hypoplasia type I and II. Pontocerebellar hypoplasia type 1 is a lethal phenotype and clinical features include congenital contractures, respiratory insufficiency, central and peripheral motor dysfunction and spinal anterior horn degeneration. Type 2 is characterized by progressive microcephaly, extrapyramidal dyskinesia and normal spinal cord findings. In this paper, we describe a girl, born at 33 weeks of gestation, presenting with respiratory insufficiency and multiple contractures. MRI scan of the brain demonstrated pontocerebellar hypoplasia and cortical and diffuse periventricular white matter abnormalities. Postmortem examination showed pontocerebellar hypoplasia with extensive gliosis of the periventricular white matter and of the basal ganglia with normal spinal cord findings. Histology of skeletal muscle was normal. Biochemical analysis demonstrated multiple deficiencies of respiratory chain enzymes in skin fibroblasts. This case demonstrates a lethal phenotype of pontocerebellar hypoplasia without spinal cord abnormalities associated with a respiratory-chain disorder. The diagnostic workup in a patient whose brain image shows pontocerebellar hypoplasia should include a search for respiratory-chain impairment.

Abnormalities, Multiple↗
PubMed1999

Bethlem myopathy: a slowly progressive congenital muscular dystrophy with contractures.

Bethlem myopathy is an early-onset benign autosomal dominant myopathy with contractures caused by mutations in collagen type VI genes. It has been reported that onset occurs in early childhood. We investigated the natural course of Bethlem myopathy in five previously published kindreds and two novel pedigrees, with particular attention to the mode of onset in 23 children and the progression of weakness in 36 adult patients. Our analysis shows that nearly all children exhibit weakness or contractures during the first 2 years of life. Early features include diminished foetal movements, neonatal hypotonia and congenital contractures which are of a dynamic nature during childhood. The course of Bethlem myopathy in adult patients is less benign than previously thought. Due to slow but ongoing progression, more than two-thirds of patients over 50 years of age use a wheelchair.

Activities of Daily Living↗
PubMed1999

Progression of abnormalities in adrenomyeloneuropathy and neurologically asymptomatic X-linked adrenoleukodystrophy despite treatment with "Lorenzo's oil".

OBJECTIVES: X-linked adrenoleukodystrophy (X-ALD) is an inherited disorder of peroxisomal fatty acid oxidation, biochemically characterised by the accumulation of saturated very long chain fatty acids (VLCFAs), particularly hexacosanoic acid (C26:0). Dietary treatment with a 4:1 mixture of glyceroltrioleate and glyceroltrierucate ("Lorenzo's oil") normalises plasma VLCFA concentrations, but neither ameliorates nor arrests the rapid progression of neurological symptoms in the cerebral variants of X-ALD. The efficacy of "Lorenzo's oil" in the milder phenotypes of X-ALD was assessed, as this has been much less investigated. METHODS: Twenty two patients who were treated with "Lorenzo's oil" for at least 12 months for a median period of 2.5 (range 1.0-6.0) years were studied. Two had asymptomatic ALD, four the "Addison only" variant, 13 adrenomyeloneuropathy (AMN), and three were symptomatic female carriers. RESULTS: The plasma C26:0 concentration normalised or near normalised in 19 patients (86%), in the three others it decreased significantly. Nevertheless, disability as measured with the extended disability status scale score increased mildly (0.5 (95% confidence interval (95% CI) 0.25-1.0)) in the 16 patients with neurological symptoms. Furthermore, one "Addison only" patient and one patient with AMN developed cerebral demyelination, and another "Addison only" patient developed AMN. Adrenocortical insufficiency evolved in one patient with AMN, and hypogonadism in one patient with asymptomatic ALD and two patients with AMN. Nerve conduction, evoked potential studies (SEP, BAEP, VEP), and abnormalities on cerebral MRI did not improve. On the other hand, side effects were often noted-namely, mild increases in liver enzymes (55%), thrombocytopenia (55%), gastrointestinal complaints (14%), and gingivitis (14%). We also found a mild decrease in haemoglobin concentration and leucocyte count. CONCLUSIONS: The data suggest that treatment with "Lorenzo's oil" neither improved neurological or endocrine function nor arrested progression of the disease. Furthermore, the oil often induced adverse effects. Therefore, it is advocated that "Lorenzo's oil" should not be prescribed routinely to patients with X-ALD who already have neurological deficits.

Adolescent↗