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1.
Muscle Nerve ; 69(4): 459-466, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38353295

RESUMEN

INTRODUCTION/AIMS: Young people with Duchenne muscular dystrophy (DMD) are at increased risk of obesity. Weight management is important to families; however, several barriers exist. This pilot study aimed to investigate the feasibility and acceptability of a co-designed weight management program for DMD. METHODS: The Supporting Nutrition and Optimizing Wellbeing Program (SNOW-P) was a single-arm diet and behavior weight management intervention delivered via weekly telehealth/phone visits over 6 weeks to young people with DMD and obesity (body mass index (BMI) ≥95th percentile) and their caregivers. Using an online survey, caregivers of boys with DMD were consulted on the structure and topics delivered in SNOW-P. Primary outcomes were feasibility and acceptability; secondary outcomes were weight, physical function, and quality of life at 6- and 12-weeks follow-up. RESULTS: Of nineteen eligible participants, eight were enrolled (median age 11.4 years, range 4.9-15.8), and seven completed the program. Visit attendance was high (88%-100%); most participants reported high satisfaction and that participation was easy. Suggested changes included online and visual DMD-specific resources. At 6-weeks, median change in weight z-scores was -0.01 (IQR: -0.23, 0.17) indicating that on average, weight gain tracked as expected for age. Waist circumference measured by caregivers lacked accuracy and the completion rate of caregiver-reported secondary outcome measures (e.g., food diaries) was low. DISCUSSION: A co-designed, telehealth/phone weight management program appeared to be feasible and acceptable in a small group of boys with DMD. An adapted, hybrid telehealth and face-to-face program is recommended for efficacy testing.


Asunto(s)
Distrofia Muscular de Duchenne , Programas de Reducción de Peso , Masculino , Humanos , Adolescente , Preescolar , Niño , Distrofia Muscular de Duchenne/terapia , Distrofia Muscular de Duchenne/complicaciones , Proyectos Piloto , Calidad de Vida , Obesidad
2.
J Paediatr Child Health ; 60(2-3): 41-46, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38545899

RESUMEN

Acute generalised muscle weakness in children is a paediatric emergency with a broad differential diagnosis. A careful history and neurologic examination guides timely investigation and management. We review some of the more common causes of acute generalised muscle weakness in children, highlighting key history and examination findings, along with an approach to lesion localisation to guide differential diagnosis and further investigation.


Asunto(s)
Síndrome de Guillain-Barré , Debilidad Muscular , Niño , Humanos , Debilidad Muscular/diagnóstico , Debilidad Muscular/etiología , Examen Neurológico , Diagnóstico Diferencial , Síndrome de Guillain-Barré/complicaciones
3.
Muscle Nerve ; 67(6): 489-496, 2023 06.
Artículo en Inglés | MEDLINE | ID: mdl-36478256

RESUMEN

INTRODUCTION/AIMS: Boys with Duchenne muscular dystrophy (DMD) are at increased risk of fracture. This study investigated the incidence of fractures, factors contributing to risk of first fracture with emphasis on body mass index (BMI), and the impact of fractures on functional capacity in an Australian cohort of boys with DMD. METHODS: A retrospective cohort study included boys with DMD who attended a pediatric neuromuscular clinic from 2011 to 2018. Information regarding fractures, anthropometry measurements, body composition and functional assessment was collected. Factors associated with first fracture risk were analyzed with Cox-proportional hazards. Longitudinal analysis of function post-fracture was also conducted. RESULTS: This study included 155 boys with DMD. At least one fracture occurred in 71 (45%) boys; overall incidence of fractures was 399-per-10,000 persons-years. The first fracture was vertebral in 55%; 41% had non-vertebral fractures and 4% had both. Vertebral fractures occurred in significantly older (12.28 vs 9.28 y) boys with longer exposure to glucocorticoids (5.45 vs 2.50 y) compared to non-vertebral fractures. Boys with a history of fracture(s) had a steeper rate of functional decline (measured by Northstar Ambulatory Assessment score) than those with no recorded fractures. DISCUSSION: A high fracture burden was observed in a large Australian cohort of boys with DMD. Further investigation is required to understand preventative strategies and modifiable risk factors to reduce the incidence of fractures in DMD. The impact on fractures on ambulatory capacity should be closely monitored.


Asunto(s)
Fracturas Óseas , Distrofia Muscular de Duchenne , Distrofia Muscular de Duchenne/complicaciones , Distrofia Muscular de Duchenne/epidemiología , Fracturas Óseas/epidemiología , Fracturas Óseas/etiología , Humanos , Masculino , Niño , Estudios Retrospectivos , Riesgo , Australia/epidemiología
4.
J Neurol Neurosurg Psychiatry ; 93(5): 530-538, 2022 05.
Artículo en Inglés | MEDLINE | ID: mdl-35140138

RESUMEN

BACKGROUND AND OBJECTIVES: Charcot-Marie-Tooth disease (CMT) is the most common inherited neuropathy and often presents during childhood. Guidelines for the optimal management of common problems experienced by individuals with CMT do not exist, for either children or adults. We formed the Paediatric CMT Best Practice Guidelines Consortium to develop evidence and consensus-based recommendations for the clinical management of children and adolescents with CMT, with the primary objective of promoting optimal, standardised care globally. METHODS: Development of this clinical practice guideline involved a series of systematic reviews covering 10 clinical questions, modified Delphi methodology involving an international panel of clinicians to generate consensus where evidence did not exist, and application of the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) approach to evaluate the body of literature and formulate recommendations. RESULTS: The final guideline includes three evidence-based and 31 consensus-based recommendations. They encompass the management of muscle weakness, balance and mobility impairment, sensory symptoms, muscle cramps, impaired upper limb function, respiratory impairment, maintenance of joint range of motion and non-surgical management of joint deformity. Consensus was not achieved in some management areas, reflecting differences in practice between clinicians and healthcare settings, and highlighting the need for further research. CONCLUSIONS: This clinical practice guideline provides practical and implementable guidance on the management of common clinical problems experienced by children with CMT and advocates for improved access to multidisciplinary care. Successful dissemination and implementation of these recommendations will be critical in ensuring their application across multiple healthcare settings.


Asunto(s)
Enfermedad de Charcot-Marie-Tooth , Adolescente , Adulto , Enfermedad de Charcot-Marie-Tooth/diagnóstico , Enfermedad de Charcot-Marie-Tooth/terapia , Niño , Consenso , Humanos , Calambre Muscular , Debilidad Muscular , Guías de Práctica Clínica como Asunto , Revisiones Sistemáticas como Asunto
5.
Cerebellum ; 21(6): 963-975, 2022 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-34855135

RESUMEN

To identify gait and balance measures that are responsive to change during the timeline of a clinical trial in Friedreich ataxia (FRDA), we administered a battery of potential measures three times over a 12-month period. Sixty-one ambulant individuals with FRDA underwent assessment of gait and balance at baseline, 6 months and 12 months. Outcomes included GAITRite® spatiotemporal gait parameters; Biodex Balance System Postural Stability Test (PST) and Limits of Stability; Berg Balance Scale (BBS); Timed 25-Foot Walk Test; Dynamic Gait Index (DGI); SenseWear MF Armband step and energy activity; and the Friedreich Ataxia Rating Scale Upright Stability Subscale (FARS USS). The standardised response mean (SRM) or correlation coefficients were reported as effect size indices for comparison of internal responsiveness. Internal responsiveness was also analysed in subgroups. SenseWear Armband daily step count had the largest effect size of all the variables over 6 months (SRM = -0.615), while the PST medial-lateral index had the largest effect size (SRM = 0.829) over 12 months. The FARS USS (SRM = 0.824) and BBS (SRM = -0.720) were the only outcomes able to detect change over 12 months in all subgroups. The DGI was the most responsive outcome in children, detecting a mean change of -2.59 (95% CI -3.52 to -1.66, p < 0.001, SRM = -1.429). In conclusion, the FARS USS and BBS are highly responsive and can detect change in a wide range of ambulant individuals with FRDA. However, therapeutic effects in children may be best measured by the DGI.


Asunto(s)
Ataxia de Friedreich , Niño , Humanos , Ataxia de Friedreich/diagnóstico , Índice de Severidad de la Enfermedad , Marcha/fisiología , Progresión de la Enfermedad , Equilibrio Postural/fisiología
6.
Muscle Nerve ; 66(1): 31-38, 2022 07.
Artículo en Inglés | MEDLINE | ID: mdl-35426158

RESUMEN

INTRODUCTION/AIMS: In response to coronavirus disease 2019 (COVID-19) pandemic restrictions int 2020, our face-to-face (F2F) multidisciplinary neuromuscular clinic (NMC) transitioned to widespread use of telehealth (TH). This study aimed to (1) understand parent/guardian, child, and clinician perceptions of TH; (2) examine TH-related changes in clinical activity; and (3) use these findings to inform a future model of care for the NMC. METHODS: A clinical audit was undertaken to examine clinical activity throughout 2018-2020. Online surveys were distributed to clinicians and parents of children attending the NMC via TH in 2020. A working group of clinicians created a checklist to guide a future hybrid model of TH and F2F care. RESULTS: Total clinical activity in 2020 was maintained from previous years; 62.8% of all appointments occurred via TH, and 82.3% of patients attended NMC by TH at least once. Ninety-nine parents (30.6% response rate), 52 children, and 17 clinicians (77% response rate) responded to the survey. All groups reported better interaction when F2F compared to TH. Eighty percent of parents identified advantages of TH and reported lower levels of stress. A lack of "hands-on" physical assessment was identified by parents and clinicians as a TH limitation. Most families (68.1% of parents; 58.8% of children) and all clinicians indicated a preference for a mix of TH and F2F NMC appointments in the future. DISCUSSION: This study has informed a checklist to guide future TH use in a new hybrid model of care. Further investigation is required to assess health impacts of TH use in pediatric neuromuscular care.


Asunto(s)
COVID-19 , Telemedicina , Instituciones de Atención Ambulatoria , Niño , Humanos , Pandemias
7.
Epilepsia ; 62(2): 358-370, 2021 02.
Artículo en Inglés | MEDLINE | ID: mdl-33475165

RESUMEN

OBJECTIVE: To study the epilepsy syndromes among the severe epilepsies of infancy and assess their incidence, etiologies, and outcomes. METHODS: A population-based cohort study was undertaken of severe epilepsies with onset before age 18 months in Victoria, Australia. Two epileptologists reviewed clinical features, seizure videos, and electroencephalograms to diagnose International League Against Epilepsy epilepsy syndromes. Incidence, etiologies, and outcomes at age 2 years were determined. RESULTS: Seventy-three of 114 (64%) infants fulfilled diagnostic criteria for epilepsy syndromes at presentation, and 16 (14%) had "variants" of epilepsy syndromes in which there was one missing or different feature, or where all classical features had not yet emerged. West syndrome (WS) and "WS-like" epilepsy (infantile spasms without hypsarrhythmia or modified hypsarrhythmia) were the most common syndromes, with a combined incidence of 32.7/100 000 live births/year. The incidence of epilepsy of infancy with migrating focal seizures (EIMFS) was 4.5/100 000 and of early infantile epileptic encephalopathy (EIEE) was 3.6/100 000. Structural etiologies were common in "WS-like" epilepsy (100%), unifocal epilepsy (83%), and WS (39%), whereas single gene disorders predominated in EIMFS, EIEE, and Dravet syndrome. Eighteen (16%) infants died before age 2 years. Development was delayed or borderline in 85 of 96 (89%) survivors, being severe-profound in 40 of 96 (42%). All infants with EIEE or EIMFS had severe-profound delay or were deceased, but only 19 of 64 (30%) infants with WS, "WS-like," or "unifocal epilepsy" had severe-profound delay, and only two of 64 (3%) were deceased. SIGNIFICANCE: Three quarters of severe epilepsies of infancy could be assigned an epilepsy syndrome or "variant syndrome" at presentation. In this era of genomic testing and advanced brain imaging, diagnosing epilepsy syndromes at presentation remains clinically useful for guiding etiologic investigation, initial treatment, and prognostication.


Asunto(s)
Discapacidades del Desarrollo/epidemiología , Epilepsias Mioclónicas/epidemiología , Espasmos Infantiles/epidemiología , Anticonvulsivantes/uso terapéutico , Preescolar , Estudios de Cohortes , Discapacidades del Desarrollo/etiología , Discapacidades del Desarrollo/fisiopatología , Progresión de la Enfermedad , Electroencefalografía , Epilepsias Mioclónicas/tratamiento farmacológico , Epilepsias Mioclónicas/etiología , Epilepsias Mioclónicas/fisiopatología , Síndromes Epilépticos/tratamiento farmacológico , Síndromes Epilépticos/epidemiología , Síndromes Epilépticos/etiología , Síndromes Epilépticos/fisiopatología , Femenino , Humanos , Incidencia , Lactante , Recién Nacido , Síndrome de Lennox-Gastaut/tratamiento farmacológico , Síndrome de Lennox-Gastaut/epidemiología , Síndrome de Lennox-Gastaut/etiología , Síndrome de Lennox-Gastaut/fisiopatología , Masculino , Malformaciones del Desarrollo Cortical/complicaciones , Malformaciones del Desarrollo Cortical/epidemiología , Malformaciones del Desarrollo Cortical/cirugía , Mortalidad , Índice de Severidad de la Enfermedad , Espasmos Infantiles/tratamiento farmacológico , Espasmos Infantiles/etiología , Espasmos Infantiles/fisiopatología , Victoria/epidemiología
8.
Brain ; 141(12): 3319-3330, 2018 12 01.
Artículo en Inglés | MEDLINE | ID: mdl-30476010

RESUMEN

Many genetic subtypes of Charcot-Marie-Tooth disease (CMT) show signs of symptomatic disease during the earliest years of life. This might be the ideal time to intervene before progression of clinical sequelae due to demyelination and axonal loss. In the absence of disease-specific clinical trial outcome measures for CMT during infancy and early childhood the aim of this study was to develop and validate a functional measure of disease severity, known as the Charcot-Marie-Tooth disease Infant Scale (CMTInfS). Development projects involved identification of a preliminary pool of 31 items representing the range of disability in affected patients aged 0-4 years from a systematic review of the literature, peer review by 12 expert clinicians and researchers in the field, design of a scoring algorithm and pilot testing in 22 participants. Subsequently, a series of validation projects were conducted based on 128 assessments of: 26 confirmed cases of inherited neuropathy (17 CMT1A, one CMT1B, one CMT1D, one CMT2C, one CMT2S, two CMT4C, one CMTX3, one Riboflavin Transporter Deficiency Type 2, and one unidentified mutation); seven 'at risk' cases and 95 unaffected healthy controls recruited through the NIH-funded Inherited Neuropathies Consortium. Validation projects included: Item, Factor and Rasch analysis, intra- and inter-rater reliability, discriminant ability and convergent validity with the CMT Pediatric Scale (CMTPedS) for children aged 3-4 years. Development and validation projects produced a psychometrically robust 15-item scale. Rasch analysis supported the viability of the CMTInfS as a unidimensional measure of disease severity and showed good overall model fit, no evidence of misfitting items or persons and was well targeted for affected children. The CMTInfS demonstrated high intra-rater reliability [intraclass correlation coefficient (ICC)3,1 0.999, 95% confidence interval 0.996-1.000) and inter-rater reliability (ICC2,1 0.997, 95% confidence interval 0.992-0.999). The CMTInfS was able to discriminate between the CMT group and controls (P = 0.006), and convergent validity demonstrated good agreement between CMTInfS and CMTPedS scores (r = 0.76, P = 0.01). The final version of the CMTInfS requires 20 min to administer and is a reliable and sensitive functional outcome measure for early onset CMT and related neuropathies.10.1093/brain/awy280_video1awy280media15970672819001.


Asunto(s)
Enfermedad de Charcot-Marie-Tooth/diagnóstico , Índice de Severidad de la Enfermedad , Enfermedad de Charcot-Marie-Tooth/genética , Preescolar , Evaluación de la Discapacidad , Progresión de la Enfermedad , Femenino , Humanos , Lactante , Recién Nacido , Masculino , Variaciones Dependientes del Observador , Psicometría , Reproducibilidad de los Resultados
9.
J Neurol Neurosurg Psychiatry ; 89(9): 937-942, 2018 09.
Artículo en Inglés | MEDLINE | ID: mdl-29549190

RESUMEN

BACKGROUND: Spinal muscular atrophy (SMA) is a devastating motor neuron disorder causing progressive muscle weakness and respiratory insufficiency. We present the initial Australian experiences implementing the expanded access programme (EAP) to enable preapproval access to nusinersen, the first disease-modifying therapy, for SMA type 1. METHODS: An Australian multicentre, open-label EAP for nusinersen enrolled patients with infantile-onset SMA type 1 from November 2016 to September 2017. Standard-of-care medical therapy and treatment with intrathecal nusinersen were provided to all patients. Clinical and diagnostic characteristics, molecular genetics, treatment administered, and functional motor outcomes were assessed. RESULTS: A total of 20 patients with SMA type 1 met the inclusion criteria, of whom 16 consented and received nusinersen treatment. Median time to diagnosis from symptom onset was 5.0 months and was correlated with age of onset (r=0.54, P<0.05). Management shifts included proactive nutritional and pulmonary support in all newly diagnosed patients with increased complexity of decision making. Supplemental nutrition with or without nocturnal non-invasive ventilation was implemented during follow-up in new diagnoses with age of onset <3 months and 2 SMN2 copies. CONCLUSIONS: The nusinersen EAP highlights difficulties in achieving early diagnosis and/or prevention, the evolution of optimal clinical care in a time of uncertain prognostication, resource implications and ethical issues in clinical practice for SMA type 1. These challenges are broadly relevant to the realisation of all novel therapeutics in neurological disorders.


Asunto(s)
Accesibilidad a los Servicios de Salud , Oligonucleótidos/uso terapéutico , Atrofias Musculares Espinales de la Infancia/diagnóstico , Atrofias Musculares Espinales de la Infancia/tratamiento farmacológico , Factores de Edad , Australia , Preescolar , Femenino , Humanos , Lactante , Masculino , Estudios Prospectivos , Resultado del Tratamiento
10.
Clin Rehabil ; 32(5): 630-643, 2018 May.
Artículo en Inglés | MEDLINE | ID: mdl-29072092

RESUMEN

OBJECTIVE: To determine the effectiveness of a six-week rehabilitation programme followed by a home exercise programme for Friedreich's ataxia. DESIGN: Randomized, delayed-start control single-blind trial. SETTING: Outpatient rehabilitation centre. SUBJECTS: Ambulant or non-ambulant individuals with Friedreich's ataxia. INTERVENTION: Participants were randomized to a six-week outpatient rehabilitation programme, immediately (intervention group) or after a six-week delayed-start (control group). The rehabilitation was followed by a six-week home exercise programme. MAIN MEASURES: The primary outcome was the Functional Independence Measure. Other measures included the Friedreich Ataxia Impact Scale and the Friedreich Ataxia Rating Scale. Outcomes were administered at baseline, 6, 12 and 18 weeks. RESULTS: Of 159 individuals screened, 92 were excluded and 48 declined to participate. A total of 19 participants were enrolled in the study. There was no significant difference in Functional Independence Measure change from baseline to six weeks in the intervention group (mean ± standard deviation, 2.00 ± 3.16) as compared to the control group (0.56 ± 4.06). Change in the Friedreich Ataxia Impact Scale body movement subscale indicated a significant improvement in health and well-being in the intervention group compared to the control group ( P = 0.003). Significant within-group improvements in the Friedreich Ataxia Impact Scale and the motor domain of the Functional Independence Measure post-rehabilitation were not sustained post-home exercise programme. CONCLUSION: Our study indicates that rehabilitation can improve health and well-being in individuals with Friedreich's ataxia; however, a larger study is required to have sufficient power to detect a significant change in the most sensitive measure of function, the motor domain of the Functional Independence Measure.


Asunto(s)
Evaluación de la Discapacidad , Terapia por Ejercicio , Ataxia de Friedreich/rehabilitación , Adulto , Atención Ambulatoria , Femenino , Humanos , Masculino , Método Simple Ciego , Tiempo de Tratamiento
12.
Neurol Neurochir Pol ; 52(2): 129-139, 2018 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-29499876

RESUMEN

Friedreich ataxia (FRDA) is a progressive neurological disorder affecting approximately 1 in 29,000 individuals of European descent. At present, there is no approved pharmacological treatment for this condition however research into treatment of FRDA has advanced considerably over the last two decades since the genetic cause was identified. Current proposed treatment strategies include decreasing oxidative stress, increasing cellular frataxin, improving mitochondrial function as well as modulating frataxin controlled metabolic pathways. Genetic and cell based therapies also hold great promise. Finally, physical therapies are being explored as a means of maximising function in those affected by FRDA.


Asunto(s)
Ataxia de Friedreich , Humanos
13.
Ann Neurol ; 79(3): 485-95, 2016 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-26704351

RESUMEN

OBJECTIVE: Friedreich ataxia (FRDA) is an inherited neurodegenerative disease characterized by ataxia and cardiomyopathy. Homozygous GAA trinucleotide repeat expansions in the first intron of FXN occur in 96% of affected individuals and reduce frataxin expression. Remaining individuals are compound heterozygous for a GAA expansion and a FXN point/insertion/deletion mutation. We examined disease-causing mutations and the impact on frataxin structure/function and clinical outcome in FRDA. METHODS: We compared clinical information from 111 compound heterozygotes and 131 individuals with homozygous expansions. Frataxin mutations were examined using structural modeling, stability analyses and systematic literature review, and categorized into four groups: (1) homozygous expansions, and three compound heterozygote groups; (2) null (no frataxin produced); (3) moderate/strong impact; and (4) minimal impact. Mean age of onset and the presence of cardiomyopathy and diabetes mellitus were compared using regression analyses. RESULTS: Mutations in the hydrophobic core of frataxin affected stability whereas surface residue mutations affected interactions with iron sulfur cluster assembly and heme biosynthetic proteins. The null group of compound heterozygotes had significantly earlier age of onset and increased diabetes mellitus, compared to the homozygous expansion group. There were no significant differences in mean age of onset between homozygotes and the minimal and moderate/strong impact groups. INTERPRETATION: In compound heterozygotes, expression of partially functional mutant frataxin delays age of onset and reduces diabetes mellitus, compared to those with no frataxin expression from the non-expanded allele. This integrated analysis of categorized frataxin mutations and their correlation with clinical outcome provide a definitive resource for investigating disease pathogenesis in FRDA.


Asunto(s)
Diabetes Mellitus/epidemiología , Diabetes Mellitus/genética , Ataxia de Friedreich/epidemiología , Ataxia de Friedreich/genética , Proteínas de Unión a Hierro/genética , Pérdida de Heterocigocidad/genética , Adolescente , Adulto , Distribución por Edad , Causalidad , Niño , Preescolar , Comorbilidad , Femenino , Marcadores Genéticos/genética , Predisposición Genética a la Enfermedad/epidemiología , Predisposición Genética a la Enfermedad/genética , Humanos , Incidencia , Lactante , Masculino , Pronóstico , Factores de Riesgo , Distribución por Sexo , Victoria/epidemiología , Adulto Joven , Frataxina
14.
Neurobiol Dis ; 94: 237-44, 2016 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-27388934

RESUMEN

Charcot-Marie-Tooth disease (CMT) is the most common inherited peripheral neuropathy. An X-linked form of CMT (CMTX6) is caused by a missense mutation (R158H) in the pyruvate dehydrogenase kinase isoenzyme 3 (PDK3) gene. PDK3 is one of 4 isoenzymes that negatively regulate the activity of the pyruvate dehydrogenase complex (PDC) by reversible phosphorylation of its first catalytic component pyruvate dehydrogenase (designated as E1). Mitochondrial PDC catalyses the oxidative decarboxylation of pyruvate to acetyl CoA and links glycolysis to the energy-producing Krebs cycle. We have previously shown the R158H mutation confers PDK3 enzyme hyperactivity. In this study we demonstrate that the increased PDK3 activity in patient fibroblasts (PDK3(R158H)) leads to the attenuation of PDC through hyper-phosphorylation of E1 at selected serine residues. This hyper-phosphorylation can be reversed by treating the PDK3(R158H) fibroblasts with the PDK inhibitor dichloroacetate (DCA). In the patient cells, down-regulation of PDC leads to increased lactate, decreased ATP and alteration of the mitochondrial network. Our findings highlight the potential to develop specific drug targeting of the mutant PDK3 as a therapeutic approach to treating CMTX6.


Asunto(s)
Enfermedad de Charcot-Marie-Tooth/metabolismo , Mitocondrias/metabolismo , Mutación , Proteínas Serina-Treonina Quinasas/genética , Adenosina Trifosfato/metabolismo , Humanos , Isoenzimas/metabolismo , Mutación/genética , Fosforilación , Piruvato Deshidrogenasa Quinasa Acetil-Transferidora
15.
Hum Mol Genet ; 22(7): 1404-16, 2013 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-23297365

RESUMEN

Hereditary motor and sensory disorders of the peripheral nerve form one of the most common groups of human genetic diseases collectively called Charcot-Marie-Tooth (CMT) neuropathy. Using linkage analysis in a three generation kindred, we have mapped a new locus for X-linked dominant CMT to chromosome Xp22.11. A microsatellite scan of the X chromosome established significant linkage to several markers including DXS993 (Zmax = 3.16; θ = 0.05). Extended haplotype analysis refined the linkage region to a 1.43-Mb interval flanked by markers DXS7110 and DXS8027. Whole exome sequencing identified a missense mutation c.G473A (p.R158H) in the pyruvate dehydrogenase kinase isoenzyme 3 (PDK3) gene. The change localized within the 1.43-Mb linkage interval, segregated with the affected phenotype and was excluded in ethnically matched control chromosomes. PDK3 is one of the four isoenzymes regulating the pyruvate dehydrogenase complex (PDC), by reversible phosphorylation, and is a nuclear-coded protein located in the mitochondrial matrix. PDC catalyzes the oxidative decarboxylation of pyruvate to acetyl CoA and is a key enzyme linking glycolysis to the energy-producing Krebs cycle and lipogenic pathways. We found that the R158H mutation confers enzyme hyperactivity and binds with stronger affinity than the wild-type to the inner-lipoyl (L2) domain of the E2p chain of PDC. Our findings suggest a reduced pyruvate flux due to R158H mutant PDK3-mediated hyper-phosphorylation of the PDC as the underlying pathogenic cause of peripheral neuropathy. The results highlight an important causative link between peripheral nerve degeneration and an essential bioenergetic or biosynthetic pathway required for the maintenance of peripheral nerves.


Asunto(s)
Enfermedad de Charcot-Marie-Tooth/genética , Enfermedades Genéticas Ligadas al Cromosoma X/genética , Mutación Missense , Proteínas Serina-Treonina Quinasas/genética , Adenosina Trifosfato/química , Adolescente , Adulto , Secuencia de Bases , Enfermedad de Charcot-Marie-Tooth/enzimología , Análisis Mutacional de ADN , Femenino , Frecuencia de los Genes , Genes Dominantes , Estudios de Asociación Genética , Enfermedades Genéticas Ligadas al Cromosoma X/enzimología , Sitios Genéticos , Heterocigoto , Humanos , Isoenzimas/genética , Escala de Lod , Masculino , Persona de Mediana Edad , Linaje , Unión Proteica , Proteínas Serina-Treonina Quinasas/química , Proteínas Serina-Treonina Quinasas/metabolismo , Subunidades de Proteína/química , Subunidades de Proteína/genética , Subunidades de Proteína/metabolismo , Piruvato Deshidrogenasa Quinasa Acetil-Transferidora , Adulto Joven
16.
J Neurol Neurosurg Psychiatry ; 86(6): 660-6, 2015 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-25112308

RESUMEN

OBJECTIVE: To explore the progression of Friedreich ataxia by analysing the change in scores of four clinical measures (the Friedreich Ataxia Rating Scale (FARS), the International Cooperative Ataxia Rating Scale (ICARS), the Functional Independence Measure (FIM) and the Modified Barthel Index (MBI)) over a period of up to 12 years, to ascertain the effects of clinical variables on performance of these measures, and to determine the most sensitive rating scale for measuring disease progression. METHODS: We measured the disease progression of up to 147 individuals against disease duration grouped into 5-year intervals. Additional subgroups were created to study the effects of the size of the smaller FXN intron 1 GAA repeat size (GAA1) and onset age on rating scale performance. RESULTS: Both the FARS and ICARS demonstrated greater change in the first 20 years post disease onset than in the subsequent 20 years during which there was little change in the mean score. While the FIM and MBI continued to deteriorate beyond 20 years post disease onset, floor effects were noted. As measured by the FARS, individuals with a larger GAA1 repeat were found to progress more quickly in the first 20 years of disease. CONCLUSIONS: Individuals with larger GAA1 repeat sizes and earlier ages of disease onset were shown to deteriorate at a faster rate and were associated with greater FARS and ICARS scores and lower FIM and MBI scores, which are indicative of greater disease severity.


Asunto(s)
Ataxia de Friedreich/terapia , Adolescente , Adulto , Edad de Inicio , Anciano , Niño , Progresión de la Enfermedad , Femenino , Estudios de Seguimiento , Ataxia de Friedreich/diagnóstico , Ataxia de Friedreich/fisiopatología , Humanos , Proteínas de Unión a Hierro/genética , Masculino , Persona de Mediana Edad , Secuencias Repetitivas de Ácidos Nucleicos , Adulto Joven , alfa-Glucosidasas/genética , Frataxina
18.
J Paediatr Child Health ; 51(8): 759-64, 2015 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-25752877

RESUMEN

Duchenne muscular dystrophy, an X-linked disorder, has an incidence of one in 5000 boys and presents in early childhood with proximal muscle weakness. Untreated boys become wheelchair bound by the age of 12 years and die of cardiorespiratory complications in their late teens to early 20s. The use of corticosteroids, non-invasive respiratory support, and active surveillance and management of associated complications have improved ambulation, function, quality of life and life expectancy. The clinical features, investigations and management of Duchenne muscular dystrophy are reviewed, as well as the latest in some of the novel therapies.


Asunto(s)
Distrofia Muscular de Duchenne , Adolescente , Niño , Humanos , Masculino , Datos de Secuencia Molecular , Distrofia Muscular de Duchenne/tratamiento farmacológico , Distrofia Muscular de Duchenne/genética , Distrofia Muscular de Duchenne/fisiopatología
19.
Mov Disord ; 29(7): 940-3, 2014 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-24390816

RESUMEN

BACKGROUND: Friedreich ataxia (FRDA) generally results from reduced frataxin, a mitochondrial protein involved in iron metabolism. We assessed whether HFE p.C282Y and/or p.H63D heterozygosity modifies age at disease onset or disease severity in individuals with FRDA. METHODS: One hundred seventy individuals with FRDA were assessed for the association of HFE p.C282Y and p.H63D with (1) age at disease onset and (2) Friedreich Ataxia Rating Scale (FARS) score. RESULTS: After adjusting for the smaller FXN GAA repeat size and sex, individuals with FRDA and heterozygous for p.C282Y had disease onset on average 3.72 years earlier than those homozygous for the wild-type amino acid (P = 0.02). Neither mutation affected disease severity as measured by FARS. CONCLUSIONS: It is hypothesized that the association between p.C282Y heterozygosity and an earlier age at FRDA onset relates to exacerbation of the already dysregulated iron metabolism that plays a major role in the pathogenesis of FRDA.


Asunto(s)
Ataxia de Friedreich/genética , Antígenos de Histocompatibilidad Clase I/genética , Proteínas de la Membrana/genética , Mutación Puntual/genética , Adolescente , Adulto , Edad de Inicio , Anciano , Niño , Femenino , Genotipo , Proteína de la Hemocromatosis , Heterocigoto , Humanos , Proteínas de Unión a Hierro/genética , Masculino , Persona de Mediana Edad , Proteínas Mitocondriales/metabolismo , Adulto Joven , Frataxina
20.
J Clin Med ; 13(7)2024 Apr 06.
Artículo en Inglés | MEDLINE | ID: mdl-38610891

RESUMEN

BACKGROUND: Auditory neuropathy (AN) is a hearing disorder that affects neural activity in the VIIIth cranial nerve and central auditory pathways. Progressive forms have been reported in a number of neurodegenerative diseases and may occur as a result of both the deafferentiation and desynchronisation of neuronal processes. The purpose of this study was to describe changes in auditory function over time in a patient with axonal neuropathy and to explore the effect of auditory intervention. METHODS: We tracked auditory function in a child with progressive AN associated with Charcot-Marie-Tooth (Type 2C) disease, evaluating hearing levels, auditory-evoked potentials, and perceptual abilities over a 3-year period. Furthermore, we explored the effect of auditory intervention on everyday listening and neuroplastic development. RESULTS: While sound detection thresholds remained constant throughout, both electrophysiologic and behavioural evidence suggested auditory neural degeneration over the course of the study. Auditory brainstem response amplitudes were reduced, and perception of auditory timing cues worsened over time. Functional hearing ability (speech perception in noise) also deteriorated through the first 1.5 years of study until the child was fitted with a "remote-microphone" listening device, which subsequently improved binaural processing and restored speech perception ability to normal levels. CONCLUSIONS: Despite the deterioration of auditory neural function consistent with peripheral axonopathy, sustained experience with the remote-microphone listening system appeared to produce neuroplastic changes, which improved the patient's everyday listening ability-even when not wearing the device.

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