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Biomedical subjects

B Echenne

Publications and source records attributed to B Echenne.

At least 55 records · Page 3Linked to original sources
PubMed1998

doublecortin is the major gene causing X-linked subcortical laminar heterotopia (SCLH).

Subcortical laminar heterotopia (SCLH), or 'double cortex', is a cortical dysgenesis disorder associated with a defect in neuronal migration. Clinical manifestations are epilepsy and mental retardation. This disorder, which mainly affects females, can be inherited in a single pedigree with lissencephaly, a more severe disease which affects the male individuals. This clinical entity has been described as X-SCLH/LIS syndrome. Recently we have demonstrated that the doublecortin gene, which is localized on the X chromosome, is implicated in this disorder. We have now performed a systematic mutation analysis of doublecortin in 11 unrelated females with SCLH (one familial and 10 sporadic cases) and have identified mutations in 10/11 cases. The sequence differences include nonsense, splice site and missense mutations and these were found throughout the gene. These results provide strong evidence that loss of function of doublecortin is the major cause of SCLH. The absence of phenotype-genotype correlations suggests that X-inactivation patterns of neuronal precursor cells are likely to contribute to the variable clinical severity of this disorder in females.

Abnormalities, Multiple↗
PubMed1998

Congenital muscular dystrophy and cerebellar atrophy.

Two siblings and two other unrelated patients had congenital muscular weakness and dystrophic changes but normal immunocytochemical stainings for merosin, dystrophin, and dystrophin-related proteins on muscle biopsy. All had marked ataxia and cerebellar atrophy or hypoplasia. Cerebral white matter and cortical organization appeared normal.

Atrophy↗
PubMed1997

Mapping of a second locus for familial hemiplegic migraine to 1q21-q23 and evidence of further heterogeneity.

Familial hemiplegic migraine (FHM) is an autosomal dominant variety of migraine with aura. We previously mapped an FHM gene on the short arm of chromosome 19. Mutations in this gene, recently shown to be the alpha1 subunit of a P/Q-type voltage-dependent calcium channel, CACNL1A4, are involved in approximately 50% of unselected FHM families and in all families where migraine attacks are associated with permanent cerebellar ataxia. As a first step toward the identification of other FHM genes, we conducted a genetic linkage analysis in one large French pedigree and showed significant linkage to two microsatellite markers D1S2635 (Zmax: 3.33 at theta = 0.05) and D1S2705 (Zmax: 3.64 at theta = 0.05), establishing the existence of a second locus for FHM (FHM2) on chromosome 1q21-q23. Analysis of six additional FHM families favored linkage to this locus in two of them; linkage was excluded in the last four families, indicating further heterogeneity. Chromosome 1-linked families differ from the ones linked to chromosome 19, because penetrance in those families is much lower, and in some of their members, epileptic seizures occur during severe migraine attacks.

Chromosome Mapping↗
PubMed1997

[Ectopic intraspinal extradural anaplastic ependymoma in an infant].

BACKGROUND: Ependymomas represent about 10% of the spinal tumors in children. Some of them may be unusually located. CASE REPORT: A 10-month-old boy was admitted for an abdominal mass syndrome with dehydration asthenia and acute bladder dysfunction. A few hours later, he developed a flaccid paraplegia. Ultrasonic and magnetic resonance spinal imaging showed a giant intraspinal tumor extending from T9 to IA level, posteriorly located to the dural compartment, widening the spinal cord. Ultrasonography also showed right ureterohydronephrosis due to the neurological bladder dysfunction. A conservative laminotomy-laminoplasty was performed in emergency. Total removal of the tumor that was attached to the right dorsal root was achieved extradurally, requiring resection of the proximal part of the root. Histological features were typical of malignant ependymoma. Chemotherapy was initiated 2 weeks later. The severe renal destruction and the persistent bladder dysfunction led to a heminephrectomy and a cystostomy, 3 weeks later. The neurological recovery was only partial with a follow-up of 18 months. CONCLUSION: Ectopic intraspinal extradural localization of ependymomas is rare and their development from a nerve root is exceptional.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1997

Merosin positive congenital muscular dystrophy with mental deficiency, epilepsy and MRI changes in the cerebral white matter.

A girl born from consanguineous Turkish parents had marked hypotonia from birth and delayed milestones. She was able to stand unaided by 3 years of age with then progressive worsening of motor abilities. She had a severe non-progressive mental deficiency. Epilepsy occurred by 6 years of age. Ophthalmological investigation was normal. A marked white matter high signal was seen on magnetic resonance imaging without cortical dysplasia. Dystrophic changes were seen on muscle biopsy. Two brothers had had a similar history with early death. Muscular immunocytochemical studies showed a normal staining for dystrophin and all dystrophin related glycoproteins (including 43 and 50 DAG). Merosin staining was normal. This case differs from Fukuyama's congenital dystrophy, from merosin negative congenital muscular dystrophy, or from other congenital muscular dystrophy with CNS dysfunction. It underlines the heterogeneity of congenital muscular dystrophy and the non-specific aspect of white matter changes on neuro-imaging.

Adult↗
PubMed1997

Linkage mapping of benign familial infantile convulsions (BFIC) to chromosome 19q.

Benign familial infantile convulsions (BFIC) are an autosomal-dominant epileptic syndrome characterized by an age of onset within the first year of life. Although they were first reported in families of Italian descent, BFIC have also been described in non-Italian families. We have mapped the BFIC gene to chromosome 19 by linkage analysis in five Italian families with a maximum two-point lod score of 6.36 at D19S114; maximum multipoint lod scores > 8 were obtained for the interval D19S250-D19S245. BFIC are therefore the third idiopathic partial epileptic syndrome to be mapped on the human genome.

Chromosome Mapping↗
PubMed1996

Total endovascular occlusion of a giant direct arteriovenous fistula in the posterior fossa in a case of Rendu-Osler-Weber disease.

We report a case of giant single-hole direct arteriovenous fistula (AVF) located in the posterior fossa of a child with Rendu-Osler-Weber disease (ROW). There is neither a clinical nor an angioarchitectural difference between AVFs associated with ROW and sporadic AVFs, but ROW should be suspected in children with multifocal pial AVFs. Transarterial embolization was performed to obliterate the AVF in a unique procedure using simultaneous bifemoral catheterization. At follow up 4 years later, the clinical examination was normal. Control MR scans and angiography showed the total occlusion of the fistula, permanent thrombosis of the venous pouch, and disappearance of the abnormal venous drainage. In this case, the endovascular procedure was available and we estimated that it represented a lesser risk than the surgical approach (risk of hemorrhage and risk of thrombosis involving the feeding arteries and the brain stem venous drainage). Furthermore, it avoids craniotomy and reduces the duration of hospitalization.

Adolescent↗
PubMed1996

Congenital non-progressive encephalopathy and deafness with intermittent episodes of coma and hyperkynureninuria.

Six of nine children born from first-cousin parents presented with the same clinical picture: non-progressive congenital encephalopathy with marked hypertonia resembling the stiff-baby syndrome, delayed milestones, mental deficiency and congenital deafness. Rare, usually reversible, episodes of sudden worsening of the neurological status, with progressive loss of consciousness and increase of hypertonia, occurred spontaneously or during febrile illnesses. During these periods, and sometimes on other occasions, transitory renal dysfunction was observed (nephrotic syndrome and/or tubular abnormalities). Death occurred before age 2 years in 4 patients; 2 are still alive (10 and 13 years old). Electrophysiological, biological and enzymatic investigations remained negative, particularly those concerning mitochondrial and peroxisomal metabolism. The only biochemical anomaly was a massive hyperkynureninuria, seen only during the periods of coma (up to 213 mumol/mmol creatinine; normal < 10) and after an intravenous protein loading test. This suggests an anomaly of tryptophan metabolism which has not been reported up to now.

Algeria↗
PubMed1996

[Schizencephaly and upper limb malformation].

BACKGROUND: Schizencephaly, a failure of the cerebral mantle to form is usually unilateral and not associated with anomalies of the controlateral limbs. We present two cases associated with such anomalies. CASE REPORTS: Case no 1. A boy born with a lobster claw deformity in the right arm. His IQ was 60 and he developed generalized seizures at the age of 4 years with spastic diplegia. MRI examination showed unilateral left schizencephaly also lined with pachygyric cortex. Case no 2. A girl was born with a right ectromelic-hand and developed left spastic hemiparesy. Her IQ was normal. She had a generalized seizure at the age of 11 years. MRI showed unilateral right schizencephaly also lined with pachygyric cortex and heterotopic periventricular gray matter. DISCUSSION: Schizencephaly seems to be due to localized ischemia in the periventricular germinal matrix during the 7th week of gestation. The limb deformity could be explained by the same vascular mechanism in the first case but not in the second one since it was homolateral to brain damage. CONCLUSION: Description of further cases is necessary to understand this association. We suggest MRI examination of brain in patients with limb deformity associated with neurological damage.

Abnormalities, Multiple↗
PubMed1996

Treatment with vigabatrin may mimic alpha-aminoadipic aciduria.

PURPOSE: We describe a secondary effect of treatment with vigabatrin (VGB). A significant increase in alpha-aminoadipic acid (AAA) occurred in plasma and urine of VGB-treated children, thus mimicking a known rare metabolic disease, alpha-aminoadipic aciduria (AAAuria). METHODS: We studied eight children, aged from 3 months to 5 years, who were receiving VGB for drug-resistant partial epilepsies. Plasma and urine amino acids were assayed with ninhydrin detection on an automated Beckman 6300 analyzer. RESULTS: In eight out of eight children, there was a significant increase of AAA in plasma and in urine. Plasma values ranged from 7 to 8 microM (control values, < 5) and urinary values from 67 to 274 mmol/mol creatinine (control values, < 25). CONCLUSIONS: The concentrations of AAA in these VGB-treated children were as high as the concentrations found in the inherited metabolic disease, AAAuria. This could lead to incorrect diagnosis and to inappropriate genetic counseling. Thus whenever a genetic metabolic disease is suspected, amino acid chromatography testing should be performed before initiation of treatment with VGB.

2-Aminoadipic Acid↗
PubMed1994

Benign infantile familial convulsions are not an allelic form of the benign familial neonatal convulsions gene.

Benign infantile familial convulsions (BIFC) and benign familial neonatal convulsions (BFNC) are two forms of familial convulsions having an age of onset within the first year of life. The gene responsible for BFNC has been mapped to chromosome 20q in the close vicinity of D20S19 and D20S20 markers. We performed linkage analysis between BIFC and D20S19-D20S20 in eight families in order to know whether the BFNC gene is also implicated in BIFC. Several apparent obligate crossovers between affected members were detected. The data here presented demonstrate that the BFNC gene is not responsible for BIFC.

Age of Onset↗
PubMed1993

[Treatment of epilepsy in children].

The general principles of treatment of epilepsies in children are summarized: control of seizures without compromission of the physical or intellectual capabilities of the patients, owing to normal family and social life. The basic principles of drug treatment, the choice and monitoring of antiepileptic drugs, and the place of the electroencephalogram are discussed.

Age Factors↗
PubMed1993

[Value of skin fibroblasts in culture for the diagnosis of mitochondrial cell dysfunction. Apropos of 5 cases with cytochrome c oxidase deficiency].

Mitochondrial respiratory chain dysfunction has been studied by two complementary methods using cultured skin fibroblasts from five patients with muscular cytochrome c oxidase (complex IV) deficiency: first, a screening test measuring lactate to pyruvate ratio (L/P) after supplementation of cultured cells; secondly, measurement of complex IV activity in whole cells. Respiratory chain defect (increased L/P ratio with decreased complex IV activity) was expressed in fibroblasts of four of the five patients. Our results show that skin fibroblasts can be helpful for biochemical diagnosis of mitochondrial respiratory chain defects.

Cells, Cultured↗