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Biomedical subjects

B Echenne

Publications and source records attributed to B Echenne.

At least 19 recordsLinked to original sources
PubMed2006

[Non epileptic paroxysmal movement disorders in childhood].

Paroxysmal movement disorders are not uncommon in childhood, but are probably under-recognised. Paroxysmal movement disorders are a distinctive group of disorders that represents various clinical situations, characterised by intermittent and episodic disturbances of movement. Diagnosis relies on semiological analysis, mainly based on parental description of the manifestations; video recording (during an EEG-video monitoring or home made video) are often helpful to establish the correct diagnosis. In the large majority of the cases, paroxysmal movement disorders are benign situations. Some of them are transient, as they spontaneously stop over time (benign torticolis of infancy, paroxysmal tonic upgaze). Being familiar with these disorders will lead to accurate diagnosis, so avoiding useless investigations. Most of the time, no treatment will be required, and the families will be informed of the good prognosis.

Child↗
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

[Genetics contribution to the understanding of autism].

Autism is a pervasive developmental disorder characterised by an impairment in social interaction and in communication, with unusual behaviour. Genetic factors are predominent in autism pathogenesis, in contrast with the environmental factors that would modulate the phenotype. The genetic polymorphism and the phenotypic heterogeneity make the autism a complex disorder to study. Genetic research on families with multiple affected children and biochemical mechanisms studies represent the sources for identifying the susceptibility genes in autism.

Autistic Disorder↗
PubMed2005

[Parry-Romberg's syndrome and epilepsy].

INTRODUCTION: Parry-Romberg's syndrome or progressive facial hemiatrophy is a rare disorder of unknown etiology which may be accompanied by neurological complications, frequently epilepsy, usually focal refractory epilepsy. The associated brain lesions are located on the same side as the half face atrophy and may progress. OBSERVATION: We report the cases of two patients with Parry-Romberg's syndrome and epilepsy. Neurosurgery was performed in one patient, enabling a histological study. CONCLUSION: The link between Parry-Romberg's syndrome and epilepsy is discussed and the neurodevelopmental theory with vascular dysgenesis is suggested.

Anticonvulsants↗
PubMed2004

Mutations within the programmed cell death 10 gene cause cerebral cavernous malformations.

Cerebral cavernous malformations (CCMs) are hamartomatous vascular malformations characterized by abnormally enlarged capillary cavities without intervening brain parenchyma. They cause seizures and cerebral hemorrhages, which can result in focal neurological deficits. Three CCM loci have been mapped, and loss-of-function mutations were identified in the KRIT1 (CCM1) and MGC4607 (CCM2) genes. We report herein the identification of PDCD10 (programmed cell death 10) as the CCM3 gene. The CCM3 locus has been previously mapped to 3q26-27 within a 22-cM interval that is bracketed by D3S1763 and D3S1262. We hypothesized that genomic deletions might occur at the CCM3 locus, as reported previously to occur at the CCM2 locus. Through high-density microsatellite genotyping of 20 families, we identified, in one family, null alleles that resulted from a deletion within a 4-Mb interval flanked by markers D3S3668 and D3S1614. This de novo deletion encompassed D3S1763, which strongly suggests that the CCM3 gene lies within a 970-kb region bracketed by D3S1763 and D3S1614. Six additional distinct deleterious mutations within PDCD10, one of the five known genes mapped within this interval, were identified in seven families. Three of these mutations were nonsense mutations, and two led to an aberrant splicing of exon 9, with a frameshift and a longer open reading frame within exon 10. The last of the six mutations led to an aberrant splicing of exon 5, without frameshift. Three of these mutations occurred de novo. All of them cosegregated with the disease in the families and were not observed in 200 control chromosomes. PDCD10, also called "TFAR15," had been initially identified through a screening for genes differentially expressed during the induction of apoptosis in the TF-1 premyeloid cell line. It is highly conserved in both vertebrates and invertebrates. Its implication in cerebral cavernous malformations strongly suggests that it is a new player in vascular morphogenesis and/or remodeling.

Apoptosis Regulatory Proteins↗
PubMed2004

[Movement disorders in childhood: therapeutic update].

Abnormal movements are not uncommon in childhood. Due to the severity of the abnormal movements or to the functional disability, a medical treatment is often required; the wide range of available pharmacological molecules and the absence of therapeutic consensus highlight the limited efficacy of the medical treatment on dystonic or athetoid movements, or severe tic disorders. The recent identification of the enzymatic defect implicated in metabolic diseases led to the development of specific treatment for newly recognized disorders, with more or less interesting results (creatine ou biotine supplementation). Recent progress in functional neurosurgery opened new fields in the treatment of movement disorders. Intrathecal baclofen was proved effective in the treatment of secondary dystonia, especially in patients with cerebral palsy. Deep brain stimulation is now an established therapy for patients with a generalized dystonic syndrome. Given the successful results of pallidal stimulation in dystonia, the indication of this procedure has been discussed in other types of abnormal movements.

Anti-Dyskinesia Agents↗
PubMed2004

Collagen VI status and clinical severity in Ullrich congenital muscular dystrophy: phenotype analysis of 11 families linked to the COL6 loci.

Ullrich's congenital muscular dystrophy (UCMD) is an autosomal recessive myopathy characterised by neonatal muscle weakness, proximal joint contractures and distal hyperlaxity. Mutations in the COL6A1, COL6A2 (21 q22.3) and COL6A3 (2 q37) genes, encoding the alpha 1, alpha 2 and alpha 3 chains of collagen VI, respectively, have been recently identified as responsible for UCMD in a total of 9 families. We investigated in detail the clinical and morphological phenotype of 15 UCMD patients from 11 consanguineous families showing potential linkage either to 21 q22.3 (6 families) or to 2 q37 (5 families). Collagen VI deficiency was confirmed on muscle biopsies or skin fibroblasts in 8 families. Although all patients shared a common phenotype, a great variability in severity was observed. Collagen VI deficiency in muscle or cultured fibroblasts was complete in the severe cases and partial in the milder ones, which suggests a correlation between the degree of collagen VI deficiency and the clinical severity in UCMD. No significant phenotypical differences were found between the families linked to each of the 2 loci, which confirms UCMD as a unique entity with underlying genetic heterogeneity.

Adolescent↗
PubMed2003

[Movement disorders in childhood: classification and genetic update].

Abnormal movements are not unusual in childhood. Recent genetic progresses provide a new approach of childhood movement disorders. Several loci have been identified in paroxysmal dyskinesia, or in Gilles de la Tourette syndrome. A gene has been cloned in Hallervorden-Spatz syndrome, and a gene has recently been implicated in benign hereditary chorea. Considerable advances concern the genetic of dystonic syndromes: several chromosomal localizations have been identified, and several genes have been cloned. Genetic advances allow nosographic reclassification of some entities and offer new molecular tools for a more appropriate diagnosis. The increasing wealth of genetic knowledge will provide further insight in the understanding of abnormal movement disorders in childhood.

Child↗
PubMed2002

[The varied etiologies of childhood-onset dystonia].

Dystonia is not uncommon in childhood, and identification of its etiology is an ultimate aim in the clinical evaluation of dystonia. Advances in neuroimaging, recent identification of gene or loci implicated in dystonic syndromes, and characterisation of new pathological entities (creatine deficiency, biotin-responsive basal ganglia disease) enlarge our understanding of childhood dystonia, and expend its diagnosis spectrum. Awareness of the diverse etiologic categories of childhood-onset dystonia is necessary to accurate diagnosis approach. Clinical examination and cerebral magnetic resonance imaging are the keys of this diagnosis approach. Primary dystonia is defined as syndromes in which dystonia is the sole phenotypic manifestation (especially no cognitive deterioration is observed, and brain MRI is normal); DYT1 dystonia, in which the abnormal gene is located on chromosome 9, is the most frequent childhood-onset primary dystonia; progressive generalisation of the abnormal movements occur in 70p.cent of the patients. Dopa - Responsive Dystonia are characterized by marked diurnal fluctuations of the dystonic symptoms and by their marked and sustained response to dopaminergic therapy; associated parkinsonian signs are usually observed later in the course of the disease. Clinical presentation of DRD might be atypical (mimicking cerebral palsy or isolated limb pain without diurnal fluctuation). DRD is rare, but a trial of L-dopa should be performed on all patients with childhood-onset dystonia, lasting at least one month. Secondary dystonias or heredodegenerative diseases are the most frequent etiology of childhood-onset dystonic syndromes. Among a huge range of heredodegenerative disease, those that are amenable to a specific treatment, such as Wilson's disease or creatine deficiency, should be particularly investigated. The main objective of investigation of dystonia is to identify secondary dystonias or heredodegenerative diseases. Further investigations will be performed according to the clinical characteristics of the dystonia, to the presence of associated neurological or extraneurological symptoms, and according to brain imaging; this approach must be discussed for each single patient. The aim of the diagnosis strategy is the rapid identification of the etiology of dystonia which will lead to accurate treatment and pertinent genetic counselling.

Circadian Rhythm↗
PubMed2001

Linkage of benign familial infantile convulsions to chromosome 16p12-q12 suggests allelism to the infantile convulsions and choreoathetosis syndrome.

The syndrome of benign familial infantile convulsions (BFIC) is an autosomal dominant epileptic disorder that is characterized by convulsions, with onset at age 3-12 mo and a favorable outcome. BFIC had been linked to chromosome 19q, whereas the infantile convulsions and choreoathetosis (ICCA) syndrome, in which BFIC is associated with paroxysmal dyskinesias, had been linked to chromosome 16p12-q12. BFIC appears to be frequently associated with paroxysmal dyskinesias, because many additional families from diverse ethnic backgrounds have similar syndromes that have been linked to the chromosome 16 ICCA region. Moreover, one large pedigree with paroxysmal kinesigenic dyskinesias only, has also been linked to the same genomic area. This raised the possibility that families with pure BFIC may be linked to chromosome 16 as well. We identified and studied seven families with BFIC inherited as an autosomal dominant trait. Genotyping was performed with markers at chromosome 19q and 16p12-q12. Although chromosome 19q could be excluded, evidence for linkage in the ICCA region was found, with a maximum two-point LOD score of 3.32 for markers D16S3131 and SPN. This result proves that human chromosome 16p12-q12 is a major genetic locus underlying both BFIC and paroxysmal dyskinesias. The unusual phenotype displayed by one homozygous patient suggests that variability of the ICCA syndrome could be sustained by genetic modifiers.

Age of Onset↗
PubMed2001

Neurological presentation of three patients with 22q11 deletion (CATCH 22 syndrome).

Chromosome 22q11 deletion (CATCH 22 syndrome or velocardiofacial syndrome) is one of the most frequent chromosomal syndromes. Neurological features other than cognitive disorders are probably the least-described part of the expanding phenotype of the 22q11 deletion. We report the neurological features of three unrelated children with a de novo deletion: one patient with an autistic disorder, a second patient with hypocalcaemic neonatal seizures and unusual persistent epileptic focus at electroencephalographic follow-up, and a third patient with atypical absence epilepsy. These observations enlarge the clinical and neurological spectrum of the 22q11 deletion. Awareness of such cases is necessary, and a diagnosis of the 22q11 deletion should be suspected in children with common neurological features associated with severe or mild dysmorphism. Diagnosis of the 22q11 deletion should be confirmed by fluorescence in situ hybridization analysis associated with standard chromosomal analysis.

Abnormalities, Multiple↗
PubMed2001

[Acute myelitis of an unusual cause in a child: the lymphocytic choriomeningitis virus].

UNLABELLED: Acute transverse myelitis is a rare disorder in childhood. It usually occurs as a post-infectious disease, but a precise infectious agent is identified in only 20% of cases. OBSERVATION: The diagnosis of acute transverse myelitis was made in a 5.5-year-old girl who initially presented with left Claude-Bernard-Horner syndrome and meningitis. A few days later, motor and sensory tetraparesia with bladder dysfunction was observed. Magnetic resonance imaging showed a diffuse lesion in the medulla, with a hypersignal in the T2 and a hyposignal in the T1 sequences. Serum analysis showed the presence of a viral infection due to the lymphocytic choriomeningitis (LCM) virus. The outcome was marked by complete recovery of the sensorimotor deficit, but a persistence of the left Claude-Bernard-Horner syndrome. CONCLUSION: In rare cases, the LCM virus is responsible for myelitis. In the present case, the Claude-Bernard-Horner syndrome was secondary to the cervico-medullary lesion. Recent reports in the literature have been discussed, in particular as regards the use of immunomodulatory therapy, which clearly improves patient prognosis.

Acute Disease↗
PubMed2001

A standardized method for the evaluation of respiratory muscle endurance in patients with Duchenne muscular dystrophy.

The aim of the study was to develop a standardized method using controlled breathing to quantify respiratory muscle endurance in children with Duchenne muscular dystrophy (DMD) and to test its reproducibility. In 10 DMD patients, all between 10 and 14 years (mean age, 11.5 +/- 1.5 years), except for two patients of 20 and 22 years, and 10 healthy children (mean age, 12 +/- 1 years), we measured the maximal time (Tlim) that a threshold load fixed at 35% of the individual maximal inspiratory pressure (Pimax) could be tolerated. We asked the children to maintain their rest breathing pattern until exhaustion using visual feedback and an auditory signal. The mean Tlim in the DMD children was 4.45 +/- 1.45 min and values were reproducible. All healthy children were able to obtain Tlim values greater than 30 min. The respiratory muscles of DMD children are more susceptible to fatigue than those of healthy subjects. This method should be satisfactory for estimating the effect of treatment and for the specific training of respiratory muscles in DMD patients without significant learning disability.

Adolescent↗