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T Voit

Publications and source records attributed to T Voit.

At least 37 records · Page 2Linked to original sources
PubMed2004

Congenital muscular dystrophy with short stature, proximal contractures and distal laxity.

We report 5 cases (2 familial and 3 sporadic) who share a diagnosis of congenital muscular dystrophy (CMD) in association with short stature, proximal contractures, rigidity of the spine and distal joint laxity as well as early respiratory failure and mild to moderate mental retardation. The expression of collagen VI was confirmed to be normal on muscle biopsies of all 5 patients and in the informative family linkage to any of the three COL6 A loci was excluded. These findings extend the phenotypes within the CMD classification.

Adolescent↗
PubMed2004

Megalencephaly and perisylvian polymicrogyria with postaxial polydactyly and hydrocephalus: a rare brain malformation syndrome associated with mental retardation and seizures.

BACKGROUND AND OBJECTIVE: Megalencephaly (MEG) or enlarged brain occurs as a mild familial variant with normal brain structure, but otherwise is an uncommon human brain malformation that may be associated with significant developmental and neurological problems. It has been classified into anatomic and metabolic subtypes. The clinical findings associated with anatomic megalencephaly have been variable and few distinct subtypes have been described. We report five unrelated children with severe congenital MEG associated with polymicrogyria (PMG), postaxial polydactyly (POLY) and hydrocephalus (HYD). METHODS: The clinical records and brain MRI of five patients have been reviewed. RESULTS: All patients had striking MEG that was symmetric in three of the five patients, and mildly asymmetric in two. The birth OFC was between +2 and +4 SD. The gyral pattern was irregular with microgyri typical of PMG, which was most severe in the perisylvian region in all five patients. Four of the five had hydrocephalus treated with a shunt. Subsequently, one of the shunted patients had small ventricles while the others had mildly to moderately enlarged lateral ventricles. Three of the five patients had postaxial polydactyly of all four limbs. The corpus callosum was dysmorphic in one patient with a fused rostrum and genu, and intact although mildly thin in the others. None were abnormally thick. All patients had severe mental retardation; three had seizures and another had an epileptiform EEG. CONCLUSION: We believe this constellation of findings (MEG-PMG-POLY-HYD) comprises a new and distinct malformation syndrome that we designate the MPPH syndrome.

Brain↗
PubMed2003

Long-term noninvasive ventilation in children and adolescents with neuromuscular disorders.

The aim of the current study was to investigate the long-term impact of nocturnal noninvasive (positive-pressure) ventilation (NIV) on sleep, sleep-disordered breathing (SDB) and respiratory function in children and adolescents with progressive neuromuscular disorders (NMD). Thirty patients (12.3 +/- 4.1 yrs) with various inherited NMD were treated with NIV for ventilatory insufficiency (n=14) or symptomatic SDB (n=16). Patients were prospectively followed with sleep studies, spirometry and peak inspiratory muscle pressure. Ten patients were studied before and after 3 nights withdrawal from NIV. NIV normalised nocturnal gas exchange in all patients and diurnal gas exchange in patients with ventilatory insufficiency. The effects persisted over 25.3 +/- 12.7 months. Nocturnal transcutaneous partial pressure of carbon dioxide improved from (baseline versus latest control) 7.1 +/- 1.3 to 5.5 +/- 0.6 kPa (53.7 +/- 9.9 to 41.6 +/- 4.8 mmHg), diurnal carbon dioxide arterial tension from 6.3 +/- 1.6 to 5.4 +/- 0.5 kPa (47.5 +/- 11.9 to 40.6 +/- 3.6 mmHg). NIV improved respiratory disturbance index, arousals from sleep, nocturnal heart rate and sleep architecture. Vital capacity decreased in five adolescents with Duchenne muscular dystrophy -183 +/- 111 mL x yr(-1) but remained stable in 25 children with other conditions (8 +/- 78 mL x yr(-1)). Three nights withdrawal of NIV in 10 previously stable patients resulted in prompt deterioration of SDB and gas exchange back to baseline but could be instantly normalised by resumption of NIV. Noninvasive (positive-pressure) ventilation has favourable long-term impact on nocturnal and diurnal gas exchange and sleep and in patients with non-Duchenne neuromuscular disorders on vital capacity as well. It is indicated in children and adolescents with symptomatic sleep-disordered breathing or ventilatory insufficiency due to neuromuscular disorders.

Adolescent↗
PubMed2002

Introduction of a ketogenic diet in young infants.

The ketogenic diet is a rational treatment for pyruvate dehydrogenase complex deficiency (McKusick 312170) and GLUT1 deficiency syndrome (McKusick 138140). An increasing number of patients are diagnosed in early infancy, but few data are available on the introduction of a ketogenic diet in this age group. GLUT1 deficiency syndrome was suspected in four infants presenting with seizures and unexplained hypoglycorrhachia. A ketogenic diet was introduced at 6-28 weeks of age. Ketosis was initiated by fasting, monitored by bedside blood glucose and 3-hydroxybutyrate determinations, and was maintained successfully using supplemented carbohydrate-free infant formula and emulgated triglycerides. All patients developed ketosis within 24 h. 3-Hydroxybutyrate concentrations available at the bedside correlated inversely with the base excess. At glucose levels < or = 40 mg/dl patients remained asymptomatic in the presence of ketones. The ketogenic formula was tolerated well, parental compliance was good, and all patients remained seizure-free on the diet. GLUT1 deficiency was confirmed in two patients; the diet was discontinued in the other two patients. In one infant, failure to thrive on medium-chain triglycerides was effectively reversed using long-chain triglycerides. Urine dipstick analyses failed to detect ketosis in another infant. Adverse effects of the diet were limited to renal stones in one patient. The ketogenic diet can be introduced and maintained successfully in young infants using long-chain fat emulsion. Monitoring 3-hydroxybutyrate at the bedside was useful for metabolic control and superior to urine dipstick analysis. Seizure control was effective and adverse effects were limited, but evaluation of the long-term effects of the ketogenic diet in this age group must await ongoing studies.

Blood Glucose↗
PubMed2002

Microlissencephaly in microcephalic osteodysplastic primordial dwarfism: a case report and review of the literature.

Microcephalic osteodysplastic primordial dwarfism (MOPD) is defined as a syndrome presenting with intrauterine and postnatal growth retardation, typical facial appearance, skeletal dysplasia and brain abnormalities. Autosomal-recessive inheritance is suspected. Sharing clinical manifestations, the former type III has been accepted to be the same entity as type I. We present the case of a male infant with MOPD I and micrencephaly with simplified gyral pattern to a degree defining it as microlissencephaly (MLIS). The brain abnormalities in MOPD I have not yet been classified. Reviewing the literature, we conclude that microlissencephaly appears to be the distinct developmental brain abnormality in MOPD I. Conversely, osteodysplastic changes have to be taken into consideration in the differential diagnosis of microlissencephaly. In addition, our patient suffered from acute lymphatic leukaemia which has not previously been described in association with MOPD I.

Agenesis of Corpus Callosum↗
PubMed2002

Patterns and predictors of sleep disordered breathing in primary myopathies.

BACKGROUND: Sleep disordered breathing (SDB) is common in neuromuscular diseases but its relationship to respiratory function is poorly defined. A study was undertaken to identify distinct patterns of SDB, to clarify the relationships between SDB and lung and respiratory muscle function, and to identify daytime predictors for SDB at its onset, for SDB with continuous hypercapnic hypoventilation, and for diurnal respiratory failure. METHODS: Upright and supine inspiratory vital capacity (IVC, % predicted), maximal inspiratory muscle pressure (PImax), respiratory drive (P(0.1)), respiratory muscle effort (P(0.1)/PImax), and arterial blood gas tensions were prospectively compared with polysomnography and capnometry (PtcCO(2)) in 42 patients with primary myopathies. RESULTS: IVC correlated with respiratory muscle function and gas exchange by day and night. SDB evolved in three distinct patterns from REM hypopnoeas, to REM hypopnoeas with REM hypoventilation, to REM/non-REM (continuous) hypoventilation, and preceded diurnal respiratory failure. SDB correlated with IVC and PImax which yielded highly predictive thresholds for SDB onset (IVC <60%, PImax <4.5 kPa), SDB with continuous hypoventilation (IVC <40%, PImax <4.0 kPa), and SDB with diurnal respiratory failure (IVC <25%, PImax <3.5 kPa). CONCLUSION: Progressive ventilatory restriction in neuromuscular diseases correlates with respiratory muscle weakness and results in progressive SDB which, by pattern and severity, can be predicted from daytime lung and respiratory muscle function.

Adolescent↗
PubMed2001

Mutations in the fukutin-related protein gene (FKRP) identify limb girdle muscular dystrophy 2I as a milder allelic variant of congenital muscular dystrophy MDC1C.

The limb girdle and congenital muscular dystrophies (LGMD and CMD) are characterized by skeletal muscle weakness and dystrophic muscle changes. The onset of symptoms in CMD is within the first few months of life, whereas in LGMD they can occur in late childhood, adolescence or adult life. We have recently demonstrated that the fukutin-related protein gene (FKRP) is mutated in a severe form of CMD (MDC1C), characterized by the inability to walk, leg muscle hypertrophy and a secondary deficiency of laminin alpha2 and alpha-dystroglycan. Both MDC1C and LGMD2I map to an identical region on chromosome 19q13.3. To investigate whether these are allelic disorders, we undertook mutation analysis of FKRP in 25 potential LGMD2I families, including some with a severe and early onset phenotype. Mutations were identified in individuals from 17 families. A variable reduction of alpha-dystroglycan expression was observed in the skeletal muscle biopsy of all individuals studied. In addition, several cases showed a deficiency of laminin alpha2 either by immunocytochemistry or western blotting. Unexpectedly, affected individuals from 15 families had an identical C826A (Leu276Ileu) mutation, including five that were homozygous for this change. Linkage analysis identified at least two possible haplotypes in linkage disequilibrium with this mutation. Patients with the C826A change had the clinically less severe LGMD2I phenotype, suggesting that this is a less disruptive FKRP mutation than those found in MDC1C. The spectrum of LGMD2I phenotypes ranged from infants with an early presentation and a Duchenne-like disease course including cardiomyopathy, to milder phenotypes compatible with a favourable long-term outcome.

Adolescent↗
PubMed2001

Sleep-disordered breathing and respiratory failure in acid maltase deficiency.

BACKGROUND: Sleep-disordered breathing (SDB) and respiratory failure (RF) are complications of acid maltase deficiency (AMD), a rare hereditary myopathy. OBJECTIVE: To define the relationship between lung and respiratory muscle function, to establish incidence and patterns of SDB, and to determine daytime predictors of SDB. METHODS: Sitting and supine lung and respiratory muscle function tests were obtained in 27 subjects with juvenile and adult AMD (aged 39 +/- 19 years) and compared with outcomes of polysomnography. RESULTS: Ventilatory restriction was present in 17/27 subjects. Inspiratory vital capacity (IVC) correlated (p < 0.005) with peak inspiratory muscle pressure (PIP, R = 0.61), respiratory muscle strain (P(0.1)/P(0.1max), R = -0.68), and gas exchange by day (PaO(2): R = 0.71; PaCO(2): R = -0.64) and night (SaO(2): R = 0.73; P(tc)CO(2): R = -0.75). Diaphragm weakness (DW) was present in 13 subjects, 10 of whom had hypercapnic RF (PaCO(2) 65 +/- 7 mm Hg), and was associated with longer disease course. SDB was found in 13 subjects, 12 with DW. It was characterized by REM-sleep hypopneas that, as ventilatory restriction worsened, were complemented by hypoventilation (P(tc)CO(2) > 50 mm Hg) first in REM sleep, then in non-REM sleep (p < 0.005). SDB was predicted by DW (sensitivity 80%, specificity 86%) and nocturnal hypoventilation by IVC < 40% (sensitivity 80%, specificity 93%). Noninvasive ventilation, instituted for daytime respiratory failure or nocturnal hypoventilation, normalized daytime and nocturnal gas exchange (p < 0.005). CONCLUSION: Vital capacity correlates with respiratory muscle function in AMD. Diaphragm weakness is the major cause of SDB and RF. SDB and nocturnal hypoventilation are predictable from daytime function tests.

Adolescent↗
PubMed2001

Mutations in the fukutin-related protein gene (FKRP) cause a form of congenital muscular dystrophy with secondary laminin alpha2 deficiency and abnormal glycosylation of alpha-dystroglycan.

The congenital muscular dystrophies (CMD) are a heterogeneous group of autosomal recessive disorders presenting in infancy with muscle weakness, contractures, and dystrophic changes on skeletal-muscle biopsy. Structural brain defects, with or without mental retardation, are additional features of several CMD syndromes. Approximately 40% of patients with CMD have a primary deficiency (MDC1A) of the laminin alpha2 chain of merosin (laminin-2) due to mutations in the LAMA2 gene. In addition, a secondary deficiency of laminin alpha2 is apparent in some CMD syndromes, including MDC1B, which is mapped to chromosome 1q42, and both muscle-eye-brain disease (MEB) and Fukuyama CMD (FCMD), two forms with severe brain involvement. The FCMD gene encodes a protein of unknown function, fukutin, though sequence analysis predicts it to be a phosphoryl-ligand transferase. Here we identify the gene for a new member of the fukutin protein family (fukutin related protein [FKRP]), mapping to human chromosome 19q13.3. We report the genomic organization of the FKRP gene and its pattern of tissue expression. Mutations in the FKRP gene have been identified in seven families with CMD characterized by disease onset in the first weeks of life and a severe phenotype with inability to walk, muscle hypertrophy, marked elevation of serum creatine kinase, and normal brain structure and function. Affected individuals had a secondary deficiency of laminin alpha2 expression. In addition, they had both a marked decrease in immunostaining of muscle alpha-dystroglycan and a reduction in its molecular weight on western blot analysis. We suggest these abnormalities of alpha-dystroglycan are caused by its defective glycosylation and are integral to the pathology seen in MDC1C.

Adult↗
PubMed2001

Functional consequences of the autosomal dominant G272A mutation in the human GLUT1 gene.

The first autosomal dominant missense mutation (G272A) reported within the human GLUT1 gene and shared by three affected family members was investigated in respect to functional consequences. Substitution of glycine-91 by site-directed mutagenesis with either aspartate or alanine resulted in a significant decrease in transport activity of GLUT1 expressed in Xenopus oocytes. Expression of mutant transporters was confirmed by immunoblot, 2-deoxy-glucose uptake and confocal laser microscopy. The data agree with 3-O-methyl-glucose uptake into patient erythrocytes and indicate that the loss of glycine rather than a hydrophilic side chain (Gly91Asp) defines the functional consequences of this mutation.

Alanine↗
PubMed2001

Clinical and genetic distinction between Walker-Warburg syndrome and muscle-eye-brain disease.

BACKGROUND: Three rare autosomal recessive disorders share the combination of congenital muscular dystrophy and brain malformations including a neuronal migration defect: muscle-eye-brain disease (MEB), Walker-Warburg syndrome (WWS), and Fukuyama congenital muscular dystrophy (FCMD). In addition, ocular abnormalities are a constant feature in MEB and WWS. Lack of consistent ocular abnormalities in FCMD has allowed a clear clinical demarcation of this syndrome, whereas the phenotypic distinction between MEB and WWS has remained controversial. The MEB gene is located on chromosome 1p32-p34. OBJECTIVES: To establish distinguishing diagnostic criteria for MEB and WWS and to determine whether MEB and WWS are allelic disorders. METHODS: The authors undertook clinical characterization followed by linkage analysis in 19 MEB/WWS families with 29 affected individuals. With use of clinical diagnostic criteria based on Finnish patients with MEB, each patient was categorized as having either MEB or WWS. A linkage and haplotype analysis using 10 markers spanning the MEB locus was performed on the entire family resource. RESULTS: Patients in 11 families were classified as having MEB and in 8 families as WWS. Strong evidence in favor of genetic heterogeneity was obtained in the 19 families. There was evidence for linkage to 1p32-p34 in all but 1 of the 11 pedigrees segregating the MEB phenotype. In contrast, linkage to the MEB locus was excluded in seven of eight of the WWS families. CONCLUSION: These results allow the classification of MEB and WWS as distinct disorders on both clinical and genetic grounds and provide a basis for the mapping of the WWS gene(s).

Adolescent↗
PubMed2001

Secondary calpain3 deficiency in 2q-linked muscular dystrophy: titin is the candidate gene.

BACKGROUND: Tibial muscular dystrophy (TMD), a late-onset dominant distal myopathy, is caused by yet unknown mutations on chromosome 2q, whereas MD with myositis (MDM) is a muscular dystrophy of the mouse, also progressing with age and linked to mouse chromosome 2. For both disorders, linkage studies have implicated titin as a potential candidate gene. METHODS: The authors analyzed major candidate regions in the titin gene by sequencing and Southern blot hybridization, and performed titin immunohistochemistry on TMD patient material to identify the underlying mutation. Western blot studies were performed on the known titin ligands in muscle samples of both disorders and controls, and analysis of apoptosis was also performed. RESULTS: The authors identified almost complete loss of calpain3, a ligand of titin, in the patient with limb-girdle MD (LGMD) with a homozygous state of TMD haplotype when primary calpain3 gene defect was excluded. Apoptotic myonuclei with altered distribution of transcription factor NF-kB and its inhibitor IkBalpha were encountered in muscle samples of patients with either heterozygous or homozygous TMD haplotype. Similar findings were confirmed in the MDM mouse. CONCLUSIONS: These results imply that titin mutations may be responsible for TMD, and that the pathophysiologic pathway following calpain3 deficiency may overlap with LGMD2A. The loss of calpain3 could be a downstream effect of the deficient TMD gene product. The significance of the secondary calpain3 defect for the pathogenesis of TMD was emphasized by similar calpain3 deficiency in the MDM mouse, which is suggested to be a mouse model for TMD. Homozygous mutation at the 2q locus may thus be capable of producing yet another LGMD.

Animals↗
PubMed2001

Autosomal dominant transmission of GLUT1 deficiency.

GLUT1 deficiency is caused by a defect in the facilitative glucose transporter GLUT1. Impaired glucose transport across brain tissue barriers is reflected by hypoglycorrhachia and results in an epileptic encephalopathy with developmental delay and motor disorders. Recently heterozygous mutations in the GLUT1 gene (1p35-31.3) have been reported in sporadic patients. Parents and siblings carried the GLUT1 wild-type, suggesting a de novo, autosomal dominant condition resulting from GLUT1 haploinsufficiency. We report a father and two children from separate marriages affected by GLUT1 deficiency and carrying a novel heterozygous missense mutation (G272A) in the GLUT1 gene. Mutations were identified by polymerase chain reaction and DNA sequencing and confirmed by restriction fragment digest. The predicted amino acid change (Gly91Asp) affects an Arg-X-Gly-Arg-Arg motif between helices 2 and 3 that represents a cytoplasmic anchor point and is highly conserved among transporters of the major facilitator superfamily down to yeast and bacteria. GLUT1 immunoreactivity was normal, but 3-O-methyl-D-glucose uptake into erythrocytes was significantly reduced, suggesting a quantitatively normal, but functionally impaired, GLUT1 protein at the cell membrane. This is the first report of autosomal dominant transmission of GLUT1 deficiency, confirming that this condition is the result of haploinsufficiency. The Gly-->Asp mutation within a highly conserved sequence highlights its importance for GLUT1 function. GLUT1 deficiency should be considered in patients with epilepsy, mental retardation and motor disorders. Our observations have bearing on the identification of this treatable disorder in pediatric and adult patients, will modify current biochemical protocols which use parental controls and will enable genetic counseling of affected families.

3-O-Methylglucose↗
PubMed2001

beta-Ureidopropionase deficiency: a novel inborn error of metabolism discovered using NMR spectroscopy on urine.

In this work, NMR investigations that led to the discovery of a new inborn error of metabolism, beta-ureidopropionase (UP) deficiency, are reported. 1D (1)H-NMR experiments were performed using a patient's urine. 3-Ureidopropionic acid was observed in elevated concentrations in the urine spectrum. A 1D (1)H-(1)H total correlation spectroscopy (TOCSY) and two heteronuclear 2D NMR techniques (heteronuclear multiple bond correlation (HMBC) and heteronuclear single-quantum correlation (HSQC)) were used to identify the molecular structure of the compound that caused an unknown doublet resonance at 1.13 ppm. Combining the information from the various NMR spectra, this resonance could be assigned to 3-ureidoisobutyric acid. These observations suggested a deficiency of UP. With 1D (1)H-NMR spectroscopy, UP deficiency can be easily diagnosed. The (1)H-NMR spectrum can also be used to diagnose patients suffering from other inborn errors of metabolism in the pyrimidine degradation pathway.

Amidohydrolases↗