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A Brice

Publications and source records attributed to A Brice.

At least 19 recordsLinked to original sources
PubMed2006

Predominant dystonia with marked cerebellar atrophy: a rare phenotype in familial dystonia.

BACKGROUND: Dystonia syndromes constitute a heterogeneous group of phenotypes that may be caused by different heredodegenerative, metabolic, or genetic diseases. OBJECTIVE: To describe the characteristics of an unusual dystonia-plus phenotype associated with cerebellar atrophy. METHODS: We selected patients with predominant dystonia and cerebellar atrophy among the 861 families referred to us for genetic testing from 1992 to 2003. The main secondary heredodegenerative causes and the major genes responsible for hereditary dystonias and autosomal dominant or recessive ataxias were excluded. RESULTS: We identified 12 patients in 8 families with an unusual dystonia-plus phenotype characterized by dystonia and cerebellar atrophy on brain MRI. The mean age at onset was 27.3 +/- 11.5 years (range: 9 to 42 years) and the mean disease duration 14.7 +/- 7.7 years (range: 4 to 30). At onset, dystonia was focal or multifocal, mainly affecting vocal cords (n = 8) and upper limbs (n = 2). During the disease course spasmodic dysphonia became severe in five patients, leading to complete aphonia in two. Dystonia became generalized in five. Cerebellar ataxia was limited to unsteadiness in most patients and progressed very slowly. The paucity of clinical cerebellar signs contrasted with the marked cerebellar atrophy on brain MRI in most patients. Four families with two affected sibs support the hypothesis of an autosomal recessive disorder. However, X-linked inheritance is possible since only men were affected. CONCLUSION: We have characterized an unusual familial phenotype associating dystonia and cerebellar atrophy in 12 male patients.

Adult↗
PubMed2006

Spine deformities in Charcot-Marie-Tooth 4C caused by SH3TC2 gene mutations.

BACKGROUND: Charcot-Marie-Tooth (CMT) disease is a heterogeneous group of inherited peripheral motor and sensory neuropathies with several modes of inheritance: autosomal dominant, X-linked, and autosomal recessive (AR) CMT. A locus responsible for the demyelinating form of ARCMT was assigned to the 5q23-q33 region (CMT4C) by homozygosity mapping. Recently, 11 mutations were identified in the SH3TC2 (KIAA1985) gene in 12 families with demyelinating ARCMT from Turkish, Iranian, Greek, Italian, or German origin. OBJECTIVE: To identify mutations in the SH3TC2 gene. METHODS: The authors searched for SH3TC2 gene mutations in 10 consanguineous CMT families putatively linked to the CMT4C locus on the basis of haplotype segregation and linkage analysis. RESULTS: Ten families had mutations, eight of which were new and one, R954X, recurrent. Six of the 10 mutations were in exon 11. Onset occurred between ages 2 and 10. Scoliosis or kyphoscoliosis and foot deformities were found in almost all patients and were often inaugural. The median motor nerve conduction velocity values (</=34 m/s) were not correlated with disease duration. The functional disability score was </=3, indicating that the patients could walk without help. Unexpectedly, typical giant axons were observed on biopsies from a large Algerian family. CONCLUSIONS: Charcot-Marie-Tooth type 4C (CMT4C) is less severe than other autosomal recessive (AR) CMT. Intrafamilial variability is important, making phenotype-genotype correlations difficult, but spine deformities are clearly a hallmark of CMT4C. In the presence of scoliosis, a neurologic examination is recommended. Giant axons on biopsies are also suggestive of CMT4C. For genetic analysis, the R954X mutation should be looked for before systematic sequencing of exon 11.

Charcot-Marie-Tooth Disease↗
PubMed2006

PTCH mutations and deletions in patients with typical nevoid basal cell carcinoma syndrome and in patients with a suspected genetic predisposition to basal cell carcinoma: a French study.

The patched (PTCH) mutation rate in nevoid basal cell carcinoma syndrome (NBCCS) reported in various studies ranges from 40 to 80%. However, few studies have investigated the role of PTCH in clinical conditions suggesting an inherited predisposition to basal cell carcinoma (BCC), although it has been suggested that PTCH polymorphisms could predispose to multiple BCC (MBCC). In this study, we therefore performed an exhaustive analysis of PTCH (mutations detection and deletion analysis) in 17 patients with the full complement of criteria for NBCCS (14 sporadic and three familial cases), and in 48 patients suspected of having a genetic predisposition to BCC (MBCC and/or age at diagnosis < or =40 years and/or familial BCC). Eleven new germline alterations of the PTCH gene were characterised in 12 out of 17 patients harbouring the full complement of criteria for the syndrome (70%). These were frameshift mutations in five patients, nonsense mutations in five patients, a small inframe deletion in one patient, and a large germline deletion in another patient. Only one missense mutation (G774R) was found, and this was in a patient affected with MBCC, but without any other NBCCS criterion. We therefore suggest that patients harbouring the full complement of NBCCS criteria should as a priority be screened for PTCH mutations by sequencing, followed by a deletion analysis if no mutation is detected. In other clinical situations that suggest genetic predisposition to BCC, germline mutations of PTCH are not common.

Basal Cell Nevus Syndrome↗
PubMed2006

The G526R glycyl-tRNA synthetase gene mutation in distal hereditary motor neuropathy type V.

BACKGROUND: Distal hereditary motor neuropathy (dHMN) or distal spinal muscular atrophy (dSMA) is a heterogeneous group of disorders characterized almost exclusively by degeneration of motor nerve fibers, predominantly in the distal part of the limbs. One subtype, dHMN type V (dHMN-V), is transmitted by autosomal dominant inheritance and predominantly involves the hands. It is allelic with Charcot-Marie-Tooth disease 2D (CMT2D), in which a similar phenotype is associated with sensory signs. Missense mutations in the glycyl-tRNA synthetase (GARS) gene have been recently reported in families with either dHMN-V, CMT2D, or both. METHODS: The authors searched for GARS mutations in eight dHMN-V families. RESULTS: The authors found the G526R missense mutation in three families (16 patients) of Algerian Sephardic Jewish origin. All patients shared a common disease haplotype, suggestive of a founder effect. The clinical phenotype consists of a slowly progressive, purely motor distal neuropathy. It starts in the hands in most patients, but also in both distal upper and lower limbs or in distal lower limbs alone. The age at onset in symptomatic individuals was between the second to fourth decades, but four mutation carriers were still asymptomatic, two of whom were already age 49 years. Electrophysiology showed that the motor fibers of the median nerve were the most affected in upper limbs. Sensory nerve action potentials were normal. CONCLUSIONS: The age at onset of patients with the G526R mutation in the GARS gene varied widely, but the clinical and electrophysiologic presentation was uniform and progressed slowly. Glycyl-tRNA synthetase mutations are a frequent cause of familial distal hereditary motor neuropathy type V but, because of the reduced penetrance of the disease, could also account for isolated cases.

Age of Onset↗
PubMed2006

Mutation analysis of the paraplegin gene (SPG7) in patients with hereditary spastic paraplegia.

BACKGROUND: Mutations in the SPG7 gene, which encodes paraplegin, are responsible for an autosomal recessive hereditary spastic paraplegia (HSP). OBJECTIVE: To screen the SPG7 gene in a large population of HSP families compatible with autosomal recessive transmission. METHODS: The authors analyzed 136 probands with pure or complex HSP for mutations in the SPG7 using denaturation high-performance liquid chromatography and direct sequencing. RESULTS: The authors identified 47 variants including 6 mutations, 27 polymorphisms, and 14 changes with unknown effects. In one family from Morocco, compound c.850_851delTTinsC and c.1742_1744delTGG heterozygous mutations were shown to be causative. This family had complex HSP with cerebellar impairment. Progression of the disease was rapid, resulting in a severe disease after 8 years of duration. Also detected were 20 families with one heterozygous mutation that was not found in a large control population. The mutations produced highly defective proteins in four of these families, suggesting that they were probably causative. Direct sequencing of all exons and reverse transcription PCR experiments demonstrated the absence of a second mutation. However, the p.Ala510Val missense substitution previously described as a polymorphism was shown to be significantly associated with HSP, suggesting that it had a functional effect. CONCLUSION: SPG7 mutations account for less than 5% of hereditary spastic paraplegia (HSP) families compatible with autosomal recessive inheritance. Cerebellar signs or cerebellar atrophy on brain imaging were the most frequent additional features in patients with SPG7 HSP. Rare nucleotide variants in SPG7 are frequent, complicating routine diagnosis.

ATPases Associated with Diverse Cellular Activitie↗
PubMed2006

The sepiapterin reductase gene region reveals association in the PARK3 locus: analysis of familial and sporadic Parkinson's disease in European populations.

BACKGROUND: Parkinson's disease is a genetically complex disease with mixed mode of inheritance. Recently, a haplotype across the sepiapterin reductase (SPR) gene, which is located in the PARK3 linkage region, was shown to modulate age of onset of Parkinson's disease in sibships from North America. OBJECTIVE: To make a thorough assessment of the SPR gene region in sporadic Parkinson's disease. METHODS: A linkage study in 122 European sibship families with five microsatellite and 17 single nucleotide polymorphism (SNP) markers in and around the SPR gene region, and an association analysis in 340 sporadic cases of Parkinson's disease and 680 control subjects from Germany with 40 SNPs. Linkage was evaluated by non-parametric linkage scores and genotypic or haplotype association was tested by regression analysis, assuming different risk effect models. RESULTS: Significant LOD scores between 2 and 3 were obtained at the two SPR-flanking markers D2S2110 and D2S1394 and seven SNP markers around the SPR gene. We found the previously reported promoter SNP rs1876487 also significantly associated with age of onset in our sib pair families (p-value 0.02). One strong linkage disequilibrium (LD) block of 45 kb including the entire SPR gene was observed. Within this LD block all 14 inter-correlated SNPs were significantly associated with Parkinson's disease affection status (p-value 0.004). CONCLUSIONS: DNA polymorphisms in a highly intercorrelated LD block, which includes the SPR gene, appear to be associated with both sporadic and familial Parkinson's disease. This confirms a previous study showing that SPR potentially modulates the onset of or risk for Parkinson's disease.

Age of Onset↗
PubMed2006

SPG3A is the most frequent cause of hereditary spastic paraplegia with onset before age 10 years.

Seven families with six different SPG3A mutations were identified among 106 with autosomal dominant hereditary spastic paraplegia (HSP). Two mutations were novel (T162P, C375R). SPG3A was twice as frequent as SPG4 in patients with onset before age 10 years (31.8%). Later onset was not observed. The phenotype was pure HSP, but disease duration was longer than in non-SPG3A/SPG4 patients, leading ultimately to greater handicap.

Adolescent↗
PubMed2006

Parkin modulates gene expression in control and ceramide-treated PC12 cells.

Mutations in the parkin gene cause autosomal-recessive early-onset parkinsonism as a result of the degeneration of mesencephalic dopaminergic neurons. In cell culture models, parkin expression has been shown to protect against cell death mediated by the sphingolipid ceramide. To determine whether the antiapoptotic effect of parkin involves changes in gene expression, we used Affymetrix oligonucleotide microarrays to analyse gene expression in stably transfected PC12 cells which conditionally overexpress parkin, that were treated or not with C2-ceramide. Overexpression of parkin and ceramide treatment both modulated gene expression. A number of the genes upregulated in the presence of ceramide, and modulated by parkin, were associated with apoptosis or cellular stress reactions. We validated the upregulation of four such genes (CHK, EIF4EBP1, GADD45A and PTPN-5) by real-time PCR after 3, 6, 9 and 12 h of ceramide treatment in cells that overexpressed parkin or not. All were upregulated 2 to 11-fold, 3 and 6 h after application of ceramide. Parkin overexpression reduced the upregulation of EIF4EBP1, GADD45A and PTPN-5, but only at 6 h. These results suggest that, in this assay, the cytoprotective effect of parkin might result not only from its E3-ligase activity, but also from direct or indirect modulation of gene expression in a time-dependent manner.

Animals↗
PubMed2006

[Autosomal recessive cerebellar ataxias with oculomotor apraxia].

INTRODUCTION: Autosomal recessive cerebellar ataxias (ARCA) comprise a phenotypically and genetically heterogeneous group of diseases. Recently, a subgroup of ARCA associated with oculomotor apraxia has been delineated. STATE OF THE ART: The ataxias with oculomotor apraxia (AOA) include four distinct genetic entities at least: ataxia-telangiectasia, ataxia telangiectasia-like disorder, ataxia with oculomotor apraxia type 1 (AOA1) and type 2 (AOA2). The responsible genes, ATM, MRE11, APTX and SETX respectively, are implicated in DNA-break repair mechanisms. CONCLUSION: We describe the phenotypic and genetic characteristics of these ataxias, based on a review of the literature and a personal study of AOA1 and AOA2 patients.

Apraxias↗
PubMed2006

Autosomal-recessive forms of demyelinating Charcot-Marie-Tooth disease.

Autosomal-recessive forms of Charcot-Marie-Tooth (ARCMT) account for less than 10% of the families in the European CMT population but are more frequent in the Mediterranean basin and the Middle East because of more widespread consanguinity. Until now, demyelinating ARCMT was more extensively studied at the genetic level than the axonal form. Since 1999, the number of localized or identified genes responsible for demyelinating ARCMT has greatly increased. Eight genes, EGR2, GDAP1, KIAA1985, MTMR2, MTMR13, NDRG1, PRX, and CTDP1, have been identified and two new loci mapped to chromosomes 10q23 and 12p11-q13. In this review, we will focus on the particular clinical and/or neuropathological features of the phenotype caused by mutations in each of these genes, which might guide molecular diagnosis.

Cataract↗
PubMed2005

Combined vitamin B6-magnesium treatment in autism spectrum disorder.

BACKGROUND: The use of mega-vitamin intervention began in the 1950s with the treatment of schizophrenic patients. Pyroxidine (vitamin B6) was first used with children diagnosed with "autism syndrome" when speech and language improvement was observed in some children as a result of large doses of B6. A number of studies attempted to assess the effects of vitamin B6-Magnesium (Mg) was found to reduce undesirable side effects from B6) on characteristics such as verbal communication, non-verbal communication, interpersonal skills, and physiological function, in individuals with autism. OBJECTIVES: To determine the efficacy of vitamin B6 and magnesium (B6-Mg) for treating social, communication, and behavioural responses of children and adults with autism. SEARCH STRATEGY: We searched the Cochrane Controlled Trials Register (Cochrane Library, Issue 2, 2002), MEDLINE (1966 to January 2002), EMBASE (1980 to January 2002), PsycINFO (1887 to January 2002), Dissertation Abstracts International (1861 to January 2002). The search engine FirstSearch was also used (January 2002). All searches were updated in April 2005. Reference lists for all the obtained studies and other review articles were examined for additional studies. SELECTION CRITERIA: All studies in which the participants had been diagnosed with autistic spectrum disorder were randomly allocated prior to intervention and in which outcomes were compared to either a placebo or non-treated group were included. DATA COLLECTION AND ANALYSIS: Two reviewers independently evaluated and extracted data from all potential studies identified for inclusion. MAIN RESULTS: This update includes a new trial (Kuriyama 2002) to bring the total of included studies to three (total n=33). One study, which used a cross-over design (Tolbert 1993) provided insufficient data to conduct an analysis. Another crossover study (Findling 1997) yielded no significant differences between treatment and placebo group performances following the B6 intervention on measures of social interaction, communication, compulsivity, impulsivity, or hyperactivity. The latest study (Kuriyama 2002) was motivated by evidence from epilepsy research and was focussed on a subgroup of children with pervasive developmental disorders (PDDs) who exhibited clinical features similar to those with pyroxidine-dependent epilepsy. This small study (n=8) only measured IQ and 'Social Quotient' and found a statistically significant benefit for IQ (5.2, 95% CI = [0.2 to 10.3]) when in the treated group, by using change scores. AUTHORS' CONCLUSIONS: Due to the small number of studies, the methodological quality of studies, and small sample sizes, no recommendation can be advanced regarding the use of B6-Mg as a treatment for autism.

Adult↗
PubMed2005

Epsilon sarcoglycan mutations and phenotype in French patients with myoclonic syndromes.

BACKGROUND: Myoclonus dystonia syndrome (MDS) is an autosomal dominant movement disorder caused by mutations in the epsilon-sarcoglycan gene (SGCE) on chromosome 7q21. METHODS: We have screened for SGCE mutations in index cases from 76 French patients with myoclonic syndromes, including myoclonus dystonia (M-D), essential myoclonus (E-M), primary myoclonic dystonia, generalised dystonia, dystonia with tremor, and benign hereditary chorea. All coding exons of the SGCE gene were analysed. The DYT1 mutation was also tested. RESULTS: Sixteen index cases had SGCE mutations while one case with primary myoclonic dystonia carried the DYT1 mutation. Thirteen different mutations were found: three nonsense mutations, three missense mutations, three splice site mutations, three deletions, and one insertion. Eleven of the SGCE index cases had M-D and five E-M. No SGCE mutations were detected in patients with other phenotypes. The total number of mutation carriers in the families was 38, six of whom were asymptomatic. Penetrance was complete in paternal transmissions and null in maternal transmissions. MDS patients with SGCE mutation had a significantly earlier onset than the non-carriers. None of the patients had severe psychiatric disorders. CONCLUSION: This large cohort of index patients shows that SGCE mutations are primarily found in patients with M-D and to a lesser extent E-M, but are present in only 30% of these patients combined (M-D and E-M).

Adolescent↗
PubMed2005

Spastin mutations are frequent in sporadic spastic paraparesis and their spectrum is different from that observed in familial cases.

BACKGROUND: SPG4 encodes spastin, a member of the AAA protein family, and is the major gene responsible for autosomal dominant spastic paraplegia. It accounts for 10-40% of families with pure (or eventually complicated) hereditary spastic paraparesis (HSP). OBJECTIVE: To assess the frequency of SPG4 mutation in patients with spastic paraplegia but without family histories. METHODS: 146 mostly European probands with progressive spastic paraplegia were studied (103 with pure spastic paraplegia and 43 with additional features). Major neurological causes of paraplegia were excluded. None had a family history of paraplegia. DNA was screened by DHPLC for mutations in the 17 coding exons of the SPG4 gene. Sequence variants were characterised by direct sequencing. A panel of 600 control chromosomes was used to rule out polymorphisms. RESULTS: The overall rate of mutations was 12%; 19 different mutations were identified in 18 patients, 13 of which were novel. In one family, where both parents were examined and found to be normal, the mutation was transmitted by the asymptomatic mother, indicating reduced penetrance. The parents of other patients were not available for analysis but were reported to be normal. There was no evidence for de novo mutations. The mutations found in these apparently isolated patients were mostly of the missense type and tended to be associated with a less severe phenotype than previously described in patients with inherited mutations. CONCLUSIONS: The unexpected presence of SPG4 gene mutations in patients with sporadic spastic paraplegia suggests that gene testing should be done in individuals with pure or complicated spastic paraplegia without family histories.

Adenosine Triphosphatases↗
PubMed2005

Molecular diagnosis of autosomal dominant early onset Alzheimer's disease: an update.

BACKGROUND: Autosomal dominant early onset Alzheimer's disease (ADEOAD) is genetically heterogeneous. Mutations of the amyloid precursor protein (APP), presenilin 1 (PSEN1), and presenilin 2 (PSEN2) genes have been identified. OBJECTIVE: To further clarify the respective contribution of these genes to ADEOAD. METHODS: 31 novel families were investigated. They were ascertained using stringent criteria (the occurrence of probable or definite cases of Alzheimer's disease with onset before 60 years of age in three generations). All cases fulfilled the NINCDS-ADRDA criteria for probable or definite Alzheimer's disease. The entire coding regions of PSEN1 and PSEN2 genes and exons 16 and 17 of APP gene were sequenced from genomic DNA RESULTS: PSEN1 mutations, including eight previously unreported mutations, were detected in 24 of the 31 families, and APP mutations were found in five families. In this sample, the mean ages of disease onset in PSEN1 and APP mutation carriers were 41.7 and 51.2 years, respectively. CONCLUSIONS: Combining these data with previously published data, yielding 65 ADEOAD families, 66% of the cases were attributable to PSEN1 mutations and 16% to APP mutations, while 18% remained unexplained.

Adult↗
PubMed2005

Parkin interacts with the proteasome subunit alpha4.

Mutations in the parkin gene encoding an E3 ligase are responsible for autosomal recessive Parkinson's disease. Putative parkin substrates and interacting partners have been identified, but the molecular mechanism underlying parkin-related neurodegeneration is still unclear. We have identified the 20S proteasomal subunit alpha4 (synonyms: PSMA7, XAPC7, subunit alpha type 7) as a new interacting partner of parkin. The C-terminal IBR-RING domain of parkin and the C-terminal part of alpha4 were essential for the interaction. Biochemical studies revealed that alpha4 was not a substrate for parkin-dependent ubiquitylation. Putative functions of the interaction might therefore be substrate presentation to the proteasome or regulation of proteasomal activity. Full-length parkin and parkin lacking the N-terminal ubiquitin-like domain slightly increased the proteasomal activity in HEK 293T cells, in line with the latter hypothesis.

Animals↗
PubMed2005

[Mutation of the aprataxin gene presenting with Charcot-Marie-Tooth-like neuropathy and cerebellar ataxia].

BACKGROUND: Phenotype-genotype correlations, generally based on predominant associated signs, are being increasingly used to distinguish different types of autosomal recessive cerebellar ataxias (ARCA). CASE REPORTS: Two brothers developed signs of cerebellar ataxia with peripheral axonal motor and sensory neuropathy, distal muscular atrophy, pes cavus and steppage gait as seen in Charcot-Marie-Tooth neuropathy. The examination also showed oculomotor apraxia. Sural nerve biopsy revealed conspicuous reduction in the density of myelinated fibres but preservation of unmyelinated nerve fibres. Blood tests revealed low serum albumin and elevated cholesterol. A homozygous W279X truncating mutation was identified in exon 6 of the APTX gene, confirming the diagnosis of cerebellar ataxia with oculomotor apraxia type 1 (AOA1). CONCLUSIONS: These cases illustrate the presentation of AOA1 type of ARCA and discuss the role of peripheral neuropathy in the differential diagnostic of the ARCAs variants.

Brain↗
PubMed2004

Imaging of dopaminergic dysfunction with [123I]FP-CIT SPECT in early-onset parkin disease.

OBJECTIVE: To investigate whether the presence of parkin gene mutations is associated with different nigrostriatal impairment than other early-onset parkinsonism. METHODS: Eighteen consecutive early-onset Parkinson disease (PD) patients (nine parkin and nine nonparkin patients) and six controls were studied with [123I]FP-CIT SPECT. RESULTS: Parkin patients had longer disease duration (15 +/- 9 vs 6 +/- 2 years, p = 0.008) and higher Unified Parkinson's Disease Rating Scale (UPDRS) motor score (35.8 +/- 13.7 vs 22.8 +/- 7.9, p = 0.025) than nonparkin patients. Caudate and putamen DAT density were reduced by 60% and 79% in parkin and by 43% and 70% in nonparkin patients. Multiple regression analysis showed that the UPDRS and the presence of parkin gene mutations, but not the disease duration, were significantly correlated with the striatal DAT density. Parkin patients showed a more symmetric DAT loss in both caudate and putamen as compared with nonparkin patients. CONCLUSIONS: Parkin-related disease may be associated with a higher degree of nigrostriatal impairment, independently of the clinical severity of the disease, and a more symmetric involvement as compared with non-parkin early-onset disease.

Adolescent↗