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Revue : GeneReviews® [Internet] Titre : Spinal Muscular Atrophy Type de document : Article Auteurs : Prior TW ; Leach ME ; Finanger E Année de publication : 3/12/2020 Langues : Anglais (eng) Mots-clés : amyotrophie spinale ; amyotrophie spinale proximale (type 0) ; amyotrophie spinale proximale (type I) ; amyotrophie spinale proximale (type II) ; amyotrophie spinale proximale adulte (type IV) ; amyotrophie spinale proximale liée à SMN1 ; amyotrophie spinale proximale type 3 ; article de synthèse ; classification des maladies ; conseil génétique ; corrélation génotype-phénotype ; description de la maladie ; diagnostic ; diagnostic différentiel ; diagnostic moléculaire ; épidémiologie ; maladie du motoneurone ; maladie neuromusculaire ; prévalence ; prise en charge thérapeutique Résumé : Initial Posting: February 24, 2000; Last Revision: December 3, 2020.
Clinical characteristics.
Spinal muscular atrophy (SMA) is characterized by muscle weakness and atrophy resulting from progressive degeneration and irreversible loss of the anterior horn cells in the spinal cord (i.e., lower motor neurons) and the brain stem nuclei. The onset of weakness ranges from before birth to adulthood. The weakness is symmetric, proximal > distal, and progressive. Before the genetic basis of SMA was understood, it was classified into clinical subtypes based on maximum motor function achieved; however, it is now apparent that the phenotype of SMN1-associated SMA spans a continuum without clear delineation of subtypes. With supportive care only, poor weight gain with growth failure, restrictive lung disease, scoliosis, and joint contractures are common complications; however, newly available targeted treatment options are changing the natural history of this disease.
Diagnosis/testing.
The diagnosis of SMA is established in a proband with a history of motor difficulties or regression, proximal muscle weakness, reduced/absent deep tendon reflexes, evidence of motor unit disease, AND/OR by the identification of biallelic pathogenic variants in SMN1 on molecular genetic testing. Increases in SMN2 copy number often modify the phenotype.
Management.
Treatment of manifestations: Therapies targeted to the underlying disease mechanism include nusinersen (Spinraza®; an antisense oligonucleotide) for the treatment of all types of SMA and onasemnogene abeparvovec-xioi (Zolgensma®; gene replacement therapy) for the treatment of type I SMA. These targeted treatments may prevent the development or slow the progression of some features of SMA; efficacy is improved when treatment is initiated before symptom onset. It is unclear what the long-term effect of these treatments will be or if new phenotypes will arise in treated individuals.
Proactive supportive treatment by a multidisciplinary team is essential to reduce symptom severity, particularly in the most severe cases of SMA. When nutrition or dysphagia is a concern, placement of a gastrostomy tube early in the course of the disease is appropriate. Standard therapy for gastroesophageal reflux disease and chronic constipation. Formal consultation and frequent follow up with a pulmonologist familiar with SMA is necessary. As respiratory function deteriorates, tracheotomy or noninvasive respiratory support may be offered. Surgical repair for scoliosis should be considered based on progression of the curvature, pulmonary function, and bone maturity. Surgical intervention for hip dislocation for those with pain.
Surveillance: Presymptomatic individuals require monitoring for the development of symptoms to determine appropriate timing to initiate targeted and/or supportive therapies. Multidisciplinary evaluation every six months or more frequently for weaker children is indicated to assess nutritional state, respiratory function, motor function, and orthopedic status, and to determine appropriate interventions.
Agents/circumstances to avoid: Prolonged fasting, particularly in the acutely ill infant with SMA.
Evaluation of relatives at risk: It is appropriate to determine the genetic status of younger, apparently asymptomatic sibs of an affected individual in order to identify as early as possible those who would benefit from prompt initiation of targeted treatment.
Genetic counseling.
SMA is inherited in an autosomal recessive manner. Each pregnancy of a couple who have had a child with SMA has an approximately 25% chance of producing an affected child, an approximately 50% chance of producing an asymptomatic carrier, and an approximately 25% chance of producing an unaffected child who is not a carrier. These recurrence risks deviate slightly from the norm for autosomal recessive inheritance because about 2% of affected individuals have a de novo SMN1 variant on one allele; in these instances, only one parent is a carrier of an SMN1 variant, and thus the sibs are not at increased risk for SMA. Carrier testing for at-risk relatives and prenatal testing for pregnancies at increased risk are possible if the diagnosis of SMA has been confirmed by molecular genetic testing in an affected family member.Lien associé : Texte complet disponible en accès libre sur Bookshelf GeneReviews® Pubmed / DOI : Pubmed : 20301526 Avis des lecteurs Aucun avis, ajoutez le vôtre !
(mauvais) 15 (excellent)
Revue : GeneReviews® [Internet] Titre : Barth Syndrome Type de document : Article Auteurs : Ferreira C ; Pierre G ; Thompson R ; Vernon H Année de publication : 09/07/2020 Langues : Anglais (eng) Mots-clés : article de synthèse ; conseil génétique ; corrélation génotype-phénotype ; description de la maladie ; diagnostic ; diagnostic différentiel ; diagnostic moléculaire ; épidémiologie ; physiopathologie ; prévalence ; prise en charge thérapeutique ; syndrome de Barth Résumé : nitial Posting: October 9, 2014; Last Update: July 9, 2020.
Clinical characteristics.
Barth syndrome is characterized in affected males by cardiomyopathy, neutropenia, skeletal myopathy, prepubertal growth delay, and distinctive facial gestalt (most evident in infancy); not all features may be present in a given affected male. Cardiomyopathy, which is almost always present before age five years, is typically dilated cardiomyopathy with or without endocardial fibroelastosis or left ventricular noncompaction; hypertrophic cardiomyopathy can also occur. Heart failure is a significant cause of morbidity and mortality; risk of arrhythmia and sudden death is increased. Neutropenia is most often associated with mouth ulcers, pneumonia, and sepsis. The nonprogressive myopathy predominantly affects the proximal muscles, and results in early motor delays. Prepubertal growth delay is followed by a postpubertal growth spurt with remarkable "catch-up" growth. Heterozygous females who have a normal karyotype are asymptomatic and have normal biochemical studies.
Diagnosis/testing.
The diagnosis of Barth syndrome is established in a male proband with either an increased monolysocardiolipin:cardiolipin ratio (if available) or a hemizygous pathogenic variant in TAZ identified by molecular genetic testing. The diagnosis of Barth syndrome is usually established in a female proband with suggestive clinical findings and a TAZ pathogenic variant identified by molecular genetic testing.
Management.
Treatment of manifestations: Standard treatment of heart failure including careful fluid and volume management and avoidance of over-diuresis and dehydration, standard heart failure medications to improve symptoms, and cardiac transplantation when heart failure is severe and intractable; consideration of antiarrhythmic medications or implantable cardiac defibrillator for cardiac arrhythmia; granulocyte colony-stimulating factor for neutropenia; physical therapy for skeletal muscle weakness; standard treatment for talipes equinovarus and/or scoliosis; feeding therapy and consideration of gastrostomy tube for persistent feeding issues; uncooked cornstarch prior to bedtime for hypoglycemia; standard treatment for developmental delay / intellectual disability.
Prevention of secondary complications: Aspirin therapy for prevention of clot formation in those with severe cardiac dysfunction and/or marked left ventricular noncompaction; antibiotic prophylaxis to prevent recurrent infections; limiting fasting or providing intravenous glucose infusion prior to planned procedures; regular monitoring of potassium levels during administration of IV fluids that contain potassium and during episodes of diarrhea; consultation with a nutritionist and/or gastroenterologist to determine optimal caloric delivery.
Surveillance: At least annual electrocardiography with Holter monitor and echocardiography; electrophysiologic study to assess for potentially serious arrhythmia as needed; complete blood count with differential with all febrile episodes and at least semiannually; measurement of height and weight, clinical assessment of strength and for scoliosis, and assessment of developmental progress and educational needs at each visit; formal developmental assessments every three to five years during childhood.
Agents/circumstances to avoid: Prolonged fasting, use of rectal thermometers in those with neutropenia, and use of succinylcholine. Growth hormone is typically discouraged unless growth hormone deficiency is conclusively established, as the majority of affected males will attain normal stature by adulthood. The muscular involvement in Barth syndrome may increase the risk for malignant hyperthermia compared to the general population.
Evaluations of relatives at risk: It is appropriate to evaluate the older and younger brothers of a proband in order to identify as early as possible those who would benefit from initiation of treatment and preventive measures.
Pregnancy management: Pregnancies of male fetuses known to have Barth syndrome should be managed by a high-risk maternal fetal obstetrician; there are no specific recommendations regarding mode, timing, or location of delivery.
Genetic counseling.
Barth syndrome is inherited in an X-linked manner. If a mother has a TAZ pathogenic variant, the chance of transmitting it in each pregnancy is 50%. Males who inherit the TAZ pathogenic variant will be affected; females who inherit the TAZ pathogenic variant are typically not affected. Affected males pass the TAZ pathogenic variant to all of their daughters and none of their sons. Testing for at-risk female relatives and prenatal testing for pregnancies at increased risk are possible if the TAZ pathogenic variant has been identified in an affected family member.Lien associé : Texte complet disponible en accès libre sur Bookshelf GeneReviews® Pubmed / DOI : Pubmed : 25299040 Avis des lecteurs Aucun avis, ajoutez le vôtre !
(mauvais) 15 (excellent)
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Charcot-Marie-Tooth (CMT) Hereditary Neuropathy Overview : Synonyms: Distal Hereditary Motor Neuropathy (dHMN), Hereditary Motor/Sensory Neuropathy (HMSN)
Bird TD
GeneReviews® [Internet], 2020
Revue : GeneReviews® [Internet] Titre : Charcot-Marie-Tooth (CMT) Hereditary Neuropathy Overview : Synonyms: Distal Hereditary Motor Neuropathy (dHMN), Hereditary Motor/Sensory Neuropathy (HMSN) Type de document : Article Auteurs : Bird TD Année de publication : 14/05/2020 Langues : Anglais (eng) Mots-clés : article de synthèse ; conseil génétique ; description de la maladie ; diagnostic différentiel ; diagnostic moléculaire ; étiologie ; maladie de Charcot-Marie-Tooth ; maladie du système nerveux périphérique ; nosologie ; prise en charge thérapeutique Résumé : Initial Posting: September 28, 1998; Last Revision: May 14, 2020.
The purpose of this overview is to increase the awareness of clinicians regarding Charcot-Marie-Tooth (CMT) hereditary neuropathy, its causes, and its management.
The following are the goals of this overview.
Goal 1. Describe the clinical characteristics of CMT hereditary neuropathy.
Goal 2. Review the causes of CMT hereditary neuropathy.
Goal 3. Provide an evaluation strategy to identify the cause of CMT hereditary neuropathy in a proband (when possible).
Goal 4. Inform genetic counseling of family members of an individual with CMT hereditary neuropathy.
Goal 5. Review management of CMT hereditary neuropathy.Lien associé : Texte complet disponible en accès libre sur Bookshelf GeneReviews® Pubmed / DOI : Pubmed : 20301532 En ligne : http://www.ncbi.nlm.nih.gov/pubmed/20301532 Avis des lecteurs Aucun avis, ajoutez le vôtre !
(mauvais) 15 (excellent)
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Maladie de Charcot-Marie-Tooth axonale : la mutation fondatrice du gène HINT1 est fréquemment retrouvée en Russie
Urtizberea JA
2020
Titre : Maladie de Charcot-Marie-Tooth axonale : la mutation fondatrice du gène HINT1 est fréquemment retrouvée en Russie Type de document : Brève Auteurs : Urtizberea JA, Auteur Année de publication : 20/02/2020 Langues : Français (fre) Mots-clés : diagnostic ; diagnostic moléculaire ; maladie de Charcot-Marie-Tooth ; maladie du système nerveux périphérique Lien associé : Lien vers la Brève du site Institut de Myologie Texte intégral : Les neuropathies héréditaires sensitivo-motrices (regroupées sous le terme de maladie de Charcot-Marie-Tooth ou CMT ou HSMN) sont des maladies neuromusculaires fréquentes, génétiquement déterminées et caractérisées par une grande hétérogénéité clinique et génétique. On les classe en fonction des données électrophysiologiques (formes démyélinisantes ou axonales) et du mode de transmission. Plus de 80 gènes ont été mis en cause dans les différentes formes de CMT. Le diagnostic moléculaire a grandement bénéficié de l’apport du séquençage à haut débit (NGS pour next sequencing).
Dans un article publié en décembre 2019, des chercheurs moscovites rapportent une fréquence très élevée de mutations dans le gène HINT1 au sein d’une très large cohorte nationale de patients atteints de CMT (tous types confondus) et génotypés en NGS. Le gène HINT1 avait déjà été incriminé dans une forme particulière de neuropathie héréditaire axonale autosomique récessive ((HSMN2) associée, de manière inconstante, à une neuromyotonie clinique et électrique. Une mutation fondatrice (c.110G>C ; p.Arg37Pro), déjà identifiée dans une précédente étude tchèque, a été retrouvée chez 34 patients (29 homozygotes et 5 hétérozygotes composés) répartis sur l’ensemble de la Fédération de Russie. Des études complémentaires d’haplotypes et d’hétérozygotie ont confirmé le caractère prévalent de cette mutation dans les populations d’origine slave. HINT1 serait ainsi responsable de 9% des formes axonales de CMT soit le deuxième gène le plus fréquemment impliqué après celui codant la mitofusine 2 (MFN2).Voir aussiAvis des lecteurs Aucun avis, ajoutez le vôtre !
(mauvais) 15 (excellent)
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HINT1 gene pathogenic variants: the most common cause of recessive hereditary motor and sensory neuropathies in Russian patients
Shchagina OA, Milovidova TB, Murtazina AF, et al.
Molecular biology reports, 2020, 47, 2, p 1331
Revue : Molecular biology reports, 47, 2 Titre : HINT1 gene pathogenic variants: the most common cause of recessive hereditary motor and sensory neuropathies in Russian patients Type de document : Article Auteurs : Shchagina OA ; Milovidova TB ; Murtazina AF ; Rudenskaya GE ; Nikitin SS ; Dadali EL ; Polyakov AV Editeur : Netherlands Année de publication : 02/2020 Pages : p 1331 Langues : Anglais (eng) Mots-clés : diagnostic ; diagnostic moléculaire ; effet fondateur ; épidémiologie ; étude de cohorte ; maladie du système nerveux périphérique ; neuropathie sensitivomotrice ; Russie Pubmed / DOI : Pubmed : 31848916 / DOI : 10.1007/s11033-019-05238-z
N° Profil MNM : 2019122 En ligne : http://www.ncbi.nlm.nih.gov/pubmed/31848916 Voir aussiAvis des lecteurs Aucun avis, ajoutez le vôtre !
(mauvais) 15 (excellent)
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Malignant Hyperthermia Susceptibility : Synonym: Malignant Hyperpyrexia
Rosenberg H, Sambuughin N, Riazi S, et al.
GeneReviews® [Internet], 2020
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Clinical and Genetic Features in a Series of Eight Unrelated Patients with Neuropathy Due to Glycyl-tRNA Synthetase (GARS) Variants
Forrester N, Rattihalli R, Horvath R, et al.
Journal of Neuromuscular Diseases, 2020, 7, 2, p 137
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Targeted next-generation sequencing panels in the diagnosis of Charcot-Marie-Tooth disease
Cortese A, Wilcox JE, Polke JM, et al.
Neurology, 2020, 94, 1
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Elévation chronique de la créatine-phospho-kinase : l’approche NGS s’avère performante et utile
Urtizberea JA
2019
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Identification of novel pathogenic copy number variations in Charcot-Marie-Tooth disease
Mortreux J, Bacquet J, Boyer A, et al.
Journal of human genetics, 2019
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Whole exome sequencing reveals a broader variant spectrum of Charcot-Marie-Tooth disease type 2
Lin S, Xu LQ, Xu GR, et al.
Neurogenetics, 2019
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Glycogen storage disease Type VI : Synonyms: GSD VI
Labrador E, Weinstein DA
GeneReviews® [Internet], 2019
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The neuro-ophthalmology of inherited myopathies
Watson E, Ahmad K, Fraser CL
Current opinion in ophthalmology, 2019, 30, 6, p 476
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Next-generation sequencing approach to hyperCKemia: A 2-year cohort study
Rubegni A, Malandrini A, Dosi C, et al.
Neurology. Genetics, 2019, 5, 5, e352
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Very Long-Chain Acyl-Coenzyme A Dehydrogenase Deficiency : Synonyms: Very Long-Chain Acyl-CoA Dehydrogenase Deficiency, VLCAD Deficiency
Leslie ND, Valencia CA, Strauss AW, et al.
GeneReviews® [Internet], 2019
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Carnitine Palmitoyltransferase II Deficiency : Synonym: CPT II Deficiency
Wieser T
GeneReviews® [Internet], 2019
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Phosphorylase Kinase Deficiency : Synonyms: Glycogen Storage Disease Type IX, GSDIX, PhK Deficiency, Phosphorylase b Kinase Deficiency
Herbert M, Goldstein JL, Rehder C, et al.
GeneReviews® [Internet], 2018
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X-Linked Centronuclear Myopathy : Synonyms: Myotubular Myopathy (MTM), XLCNM, X-Linked Centronuclear Myopathy, XLMTM
Dowling JJ, Lawlor MW, Das S
GeneReviews® [Internet], 2018
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