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Biomedical subjects

A Vandenberghe

Publications and source records attributed to A Vandenberghe.

At least 19 recordsLinked to original sources
PubMed2004

[Hereditary neuropathy with liability to pressure palsy presenting with an acute inflammatory demyelinating polyneuropathy].

INTRODUCTION: Hereditary neuropathy with liability to pressure palsy (HNPP) is an autosomal dominant peripheral neuropathy characterized by compressive focal neuropathies and an underlying sensorimotor demyelinative polyneuropathy. It is usually caused by a 1.5 Mb deletion of the PMP22 gene (17p11.2). CASE REPORT: We describe the case of a 31 year-old woman who presented with acute demyelinative peripheral polyneuropathy affecting the four limbs and elevated cerebrospinal fluid protein content a few days after a viral illness. Acute inflammatory demyelinating polyneuropathy (AIDP, Guillain-Barré syndrome) was suspected. However, electrophysiologic examination suggested HNPP and subsequent genetic testing was confirmatory. CONCLUSION: This case demonstrates that HNPP can present in an acute manner, mimicking AIDP.

Acute Disease↗
PubMed2002

Online health networks.

Healthcare networks function as a structural synergy serving the various healthcare actors, including the patient, who is the beneficiary. Medically speaking, they meet the need of healthcare professionals for targeted information sharing with regard to the medical record. Economically speaking, they may represent an added value and/or a diminution of costs, thus contributing to quality of care. The adoption of the same standards for all concerned servers is an absolute prerequisite if multidisciplinary applications are to be generated, as well as related services of an informational and educational nature.

Computer Security↗
PubMed2002

Setting up a common architecture for EPR in primary care: the Belgian experience.

A couple of years ago, the Belgian Federal Ministry of Health decided to back the development of a basic conceptual model for Electronic Patient Record (EPR) in primary care. Using consensus and modeling relational techniques, a working group of experts and experienced practitioners identified 7 key structuring concepts: Health Care Element, Health Approach, Contact, Subcontact, Service, Health Agent, Period. This model could roughly be seen as a restrictive sub-model of the current CEN proposal (prENV 13940) or as a first step to assess this CEN pre-Norm in Belgium. The conceptual model is already used in teaching activities and in a Belgian software labeling process.

Belgium↗
PubMed2001

Variations in primer sequences are the origin of allele drop-out at loci D13S317 and CD4.

STRs have become almost the exclusive tool of genetic scientists in forensic typing work. Consequently, large numbers of samples are genotyped and the detection of rare abnormalities is to be expected. We found rare losses of alleles, also known as drop-out, at the two STR loci D13S317 and CD4. Drop-out at D13S317 was accidentally found in typing of suspects in a murder case and three other examples of drop-out were found at locus CD4 during paternity testing. The lost alleles reappeared when alternative PCR primer pairs were used. Sequences of lost alleles were characterised at the molecular level after cloning. Variations were found in the primer sequences and these are believed to prevent amplification or to reduce amplification yield and to be the origin of the allele drop-out.

Alleles↗
PubMed2001

Flemish population data and sequence structure of the hypervariable tetranucleotide repeat locus D12S1090.

The allele frequency and sequence structure of the STR locus D12S1090 were investigated in 598 Flemish individuals. The locus shows a complex organisation with repetitions of GATA interrupted by TA and other tetra- and pentanucleotide blocks. No deviation from Hardy-Weinberg equilibrium was observed. The extensive polymorphism makes it a powerful tool for identity as well as paternity testing and even permits differentiation of closely related populations, such as Flemish and Germans. D12S1090 seems to be one of the most informative STRs, however, as seen in other highly variable STRs, the observed mutation frequency of 5.1 x 10(-3), is relatively high. of STR loci is typing highly polymorphic STRs such as ACTBP2 [3]. We thus investigated the tetranucleotide (GATA) repeat locus D12S1090 (GDB accession number GDB:376560, also known as GATA5A09) in a population sample from Flanders, the Dutch speaking part of Belgium. Although this STR is considered to be highly polymorphic [4], compared with other STRs, it has only scarcely been studied.

Alleles↗
PubMed2001

Histopathological features of X-linked Charcot-Marie-Tooth disease in 8 patients from 6 families with different connexin32 mutations.

There is still confusion as to whether X-linked Charcot-Marie-Tooth disease (CMTX) is primarily an axonal disorder or is primarily demyelinating. Eight symptomatic patients, 7 males and 1 female, from 6 families with identified connexin32 mutations underwent a superficial peroneal nerve biopsy. Quantitative and ultrastructural studies were performed, and histopathological lesions in these 8 patients proved to be quite homogeneous. The myelinated fiber count was within normal values or only moderately decreased. In 7 cases, the distribution of myelinated fibers was unimodal due to a loss of large fibers, coexisting with numerous clusters of small regenerating fibers. At ultrastructural level, these clusters were often surrounded by flattened Schwann cell processes giving an aspect of "pseudo-onion bulb" formation. There was no "naked axon" (ie, demyelinated axon), and real "onion bulb" formations composed of flattened Schwann cell processes surrounding an isolated myelinated fiber were discrete and not numerous. Macrophages laden with myelin debris were scarce or absent in the endoneurium. Several fibers appeared discretely hypomyelinated and the calculated g-ratio was scarcely higher than the mean control value. Lesions of unmyelinated fibers were absent in 7 cases and mild in one. Given that the primary defect concerns connexin32, we think that the histopathological features observed in our patients correspond to primary hypomyelination rather than to ongoing demyelination. The associated axonal degeneration might be secondary to defective axon-Schwann cell interactions.

Adolescent↗
PubMed2001

Mild recurrent neuropathy in CMT1B with a novel nonsense mutation in the extracellular domain of the MPZ gene.

Clinical, electrophysiological, and neuropathological features are reported associated with a novel heterozygote point mutation in the extracellular domain of the MPZ gene, where a transversion at codon 71 in exon 3 leads to a codon stop: Glu71stop (ie GAA-->TAA). A 36 year old woman developed a mild recurrent neuropathy after intensive manual work. The motor nerve conduction velocities were slow without conduction blocks and the nerve biopsy showed signs of demyelination-remyelination, axonal loss, and regular uncompacted myelin lamellae. She inherited the mutation from her father who displayed the same mutation with a normal phenotype. This nonsense mutation may cause a dosage difference of normal P0, and is probably underrepresented in the current mutation data bases. This report further extends the phenotype of MPZ mutations and also emphasises that mild phenotype of CMT1B may be more frequent than has been appreciated.

Adult↗
PubMed2001

Polymorphic short tandem repeats for diagnosis of the Charcot-Marie-Tooth 1A duplication.

BACKGROUND: A 1.5-Mb microduplication containing the gene for peripheral myelin protein 22 (PMP22) on chromosome 17p11.2-12 is responsible for 75% of cases of the demyelinating form of Charcot-Marie-Tooth disease (CMT1A). Methods for molecular diagnosis of CMT1A use Southern blot and/or amplification by PCR of polymorphic poly(AC) repeats (microsatellites) located within the duplicated region, or the detection of junction fragments specific for the duplication. Difficulties with both strategies have led us to develop a new diagnostic strategy with highly polymorphic short tandem repeats (STRs) located inside the CMT1A duplicated region. METHODS: We tested 10 STRs located within the duplication for polymorphic behavior. Three STRs were selected and used to test a set of 130 unrelated CMT1A patients and were compared with nonduplicated controls. The study was then extended to a larger population of patients. Alleles of interest were sequenced. A manual protocol using polyacrylamide electrophoresis and silver staining and an automated capillary electrophoresis protocol to separate fluorescently labeled alleles were validated. RESULTS: We identified three new STRs covering 0.55 Mb in the center of the CMT1A duplication. One marker, 4A, is located inside the PMP22 gene. The two others, 9A and 9B, more telomerically positioned, have the highest observed heterozygosity reported to date for CMT1A markers: 0.80 for 9A, and 0.79 for 9B. Tetra- and pentanucleotide repeats offered clear amplification, accurate sizing, and easy quantification of intensities. CONCLUSIONS: Combined use of the three STRs allows robust diagnosis with almost complete informativeness. In our routine diagnosis for CMT1A, they have replaced the use of other polymorphic markers, either in a manual adaptation or combined with fluorescence labeling and allele sizing on a DNA sequencer.

Charcot-Marie-Tooth Disease↗
PubMed2000

Analysis of eight STR loci in two Hungarian populations.

A collection of eight STR loci (D3S1358, FGA, D8S1179, D21S11, D18S51, D5S818, D13S317, D7S820) was used to generate allele frequency databases for two Hungarian population samples, Caucasians from the Budapest area and Romanies from Baranya county. During the analysis two intermediate sized alleles and a sequence variant allele were observed at the D7S820 locus. All three types of allelic variants were found to have modification (deletion, insertion, transversion) in the same block of a (T)(9) stretch located within the 3' flanking region of each allele, which may indicate a possible higher mutation rate of this (T)(9) block. For the loci D3S1358 and D7S820 the Romany population database showed departures from Hardy-Weinberg equilibrium. The forensic efficiency values for the Romany population were slightly different from those found in the Hungarian Caucasian population. Comparing the allele frequency values by G-statistic, calculating the F(st) indices and with the pairwise comparisons of inter-population variance, the two Hungarian populations could be distinguished using data of the eight STR loci.

Consanguinity↗
PubMed2000

Analysis of eight STR loci in two Hungarian populations.

A multiplex reaction for the eight STR loci D3S1358, FGA, D8S1179, D21S11, D18S51, D5S818, D13S317, D7S820 was used to generate allele frequency databases for two Hungarian population samples, Caucasians from the Budapest area and Romanies from Baranya county. During the analysis two intermediate-sized alleles and a sequence variant allele were observed at the D7S820 locus. All three types of allelic variants were found to have modifications in the same block of a (T)9 stretch located within the 3' flanking region of each allele, which may indicate a possible higher mutation rate of this (T)9 block. For the loci D3S 1358 and D7S820 the Romany population database showed departures from Hardy-Weinberg equilibrium. The forensic efficiency values for the Romany population were slightly different from those found in the Hungarian Caucasian population. Comparing the allele frequency values by G-statistic, calculating the F(ST) indices and with the pair-wise comparisons of interpopulation variance, the two Hungarian populations could be distinguished using data from the eight STR loci.

Albania↗
PubMed2000

[Hereditary neuropathy with tendency to pressure palsies (HNPP) in a child: clinical and biological diagnosis. A case report].

UNLABELLED: HNPP occurs rarely but not exceptionally during childhood. CASE REPORT: José M., seven years old, presented an isolated radial nerve palsy of progressive onset with no other clinical feature. There was no family history of neurological disorder. The electromyogram (EMG) showed a 'mosaic-like' pattern of extended sensitive and motor alterations, with diminished conduction velocities and amplitudes and increased distal latencies. HNPP was considered through the association of an isolated radial nerve palsy with an asymptomatic polyneuropathy, and was confirmed by molecular biology. CONCLUSION: HNPP is generally considered on clinical features, heredity and EMG findings. Molecular biology confirms the diagnosis in most of the cases, even in apparently sporadic patients, and is of great interest in atypical cases.

Child↗
PubMed2000

Mutational analysis and genotype/phenotype correlation in Turkish Charcot-Marie-Tooth Type 1 and HNPP patients.

The major Charcot- Marie-Tooth Type 1 (CMT1) locus, CMT1A, and Hereditary neuropathy with liability to pressure palsies (HNPP) cosegregate with a 1.5-Mb duplication and a 1.5-Mb deletion, respectively, in band 17p11.2. Point mutations in peripheral myelin gene 22 (PMP22), myelin protein zero (MPZ), and connexin 32 (Cx32) have been reported in CMT1, and in PMP22 in HNPP patients without deletion. We have screened 54 CMT1 patients, of variable clinical severity, and 25 HNPP patients from Turkey, with no duplication or deletion, for mutations in the PMP22 and Cx32 genes. A novel frameshift mutation affecting the second extracellular domain of PMP22 was found in an HNPP patient, while a point mutation in the second transmembrane domain of the protein was detected in a CMT1 patient. Two point mutations affecting different domains of Cx32 were identified in two CMTX patients. Another patient was found to carry a polymorphism in a non-conserved codon of the Cx32 gene. The clinical phenotypes of the patients correlate well with the effect of the mutation on the protein.

Adolescent↗
PubMed2000

Chronic inflammatory demyelinating polyneuropathy caused by HIV infection in a patient with asymptomatic CMT 1A.

It is well known that patients with Charcot-Marie-Tooth (CMT) disease are liable to present with episodes of cortisone-responsive demyelination, and a superimposed inflammatory component has been suggested. We report a patient who presented with a chronic inflammatory demyelinating polyneuropathy due to a recent HIV infection, which revealed a previously asymptomatic CMT 1A disease documented by identification of the characteristic duplication on the p11.2 region of chromosome 17. The inflammatory process was characterized by pathologic findings on a superficial peroneal nerve biopsy, and the patient improved significantly after corticotherapy. This report gives support to the hypothesis of a genetic susceptibility to inflammatory demyelinating processes in certain CMT kindreds.

Adult↗
PubMed2000

A novel C202F mutation in the connexin26 gene (GJB2) associated with autosomal dominant isolated hearing loss.

Mutations in the GJB2 gene encoding connexin26 (CX26) account for up to 50% of cases of autosomal recessive hearing loss. In contrast, only one GJB2 mutation has been reported to date in an autosomal dominant form of isolated prelingual hearing loss. We report here a novel heterozygous 605G-->T mutation in GJB2 in all affected members of a large family with late childhood onset of autosomal dominant isolated hearing loss. The resulting C202F substitution, which lies in the fourth (M4) transmembrane domain of CX26, may impair connexin oligomerisation. Finally, our study suggests that GJB2 should be screened for heterozygous mutations in patients with autosomal dominant isolated hearing impairment, whatever the severity of the disease.

Adolescent↗
PubMed2000

Myelin widenings and MGUS-IgA: an immunoelectron microscopic study.

A few studies have reported a variety of nonspecific histological lesions in patients with IgA monoclonal gammopathies and polyneuropathy. In our case, using electron microscopy, we observed widenings of the myelin lamellae identical to those commonly described in IgM neuropathies with anti-myelin-associated glycoprotein activity. Using immunoelectron microscopy, we demonstrated a direct involvement of IgA in myelin lesions. The search for a direct link between monoclonal dysglobulinemia, regardless of type, and polyneuropathy is important and may influence treatment.

Aged↗
PubMed1999

Alternative exon 3 splicing of the human major protein zero gene in white blood cells and peripheral nerve tissue.

The major protein zero (MPZ) is involved in peripheral myelin folding. Using nested reverse transcription-PCR, we amplified several fragments of MPZ mRNAs in white blood cells and in peripheral nerve tissue. Cloning of PCR products revealed the existence of three alternative splicing patterns: one resulted in the complete loss of exon 3 and two others induced partial skipping of the exon 3 sequence. All three alternative splicing mechanisms produced a frame-shift and created an identical premature stop codon in exon 4. We conclude that the existence of these MPZ RNA transcript variants may be the result of deliberate splicing decisions and may have functional implications in the cell.

Actins↗