Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 81
Filtrar
1.
Ann Indian Acad Neurol ; 27(1): 53-57, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38495238

RESUMO

Background: Electrocardiography (ECG) remains an excellent screening tool for cardiac assessment in Duchenne muscular dystrophy (DMD), but an accurate interpretation requires comparison with age-matched healthy controls. Objective: We examined various ECG parameters in children with DMD, in comparison with age-matched controls. Methods: Standard 12-lead ECG tracings of serial patients were screened for quality and selected. Controls were healthy, age-matched school-going children. Both quantitative and qualitative ECG parameters were analyzed. Results: After screening, ECGs from 252 patients with DMD (8.32 ± 3.12 years, 2-21 years) and ECGs from 151 age-matched healthy controls (9.72 ± 2.23, 4-19 years) were included. A significantly higher heart rate, shorter R-R interval, and taller R wave in V1 were seen across all age group of DMD in comparison to controls, with the difference increasing with age. While QT prolongation was seen in all age groups of DMD, QTc prolongation was seen only at 10 years or more. Incomplete right bundle branch block (RBBB) and pathological Q waves in inferolateral leads were exclusive in DMD, with the latter declining with age. Evidence for left ventricular (LV) pathology, such as tall R in V5/V6, increase in SV1 + RV6 height, and QRS complex duration, were seen only in the age group of 10 years or more. Conclusion: Stratification based on age and comparison with age-matched healthy subjects showed that several ECG parameters were influenced by age, and it also identified age-dependent evidence for LV pathology and QTc prolongation in DMD.

2.
J Neurol ; 2024 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-38549004

RESUMO

BACKGROUND: Peripheral neuropathies in mitochondrial disease are caused by mutations in nuclear genes encoding mitochondrial proteins, or in the mitochondrial genome. Whole exome or genome sequencing enable parallel testing of nuclear and mtDNA genes, and it has significantly advanced the genetic diagnosis of inherited diseases. Despite this, approximately 40% of all Charcot-Marie-Tooth (CMT) cases remain undiagnosed. METHODS: The genome-phenome analysis platform (GPAP) in RD-Connect was utilised to create a cohort of 2087 patients with at least one Human Phenotype Ontology (HPO) term suggestive of a peripheral neuropathy, from a total of 10,935 patients. These patients' genetic data were then analysed and searched for variants in known mitochondrial disease genes. RESULTS: A total of 1,379 rare variants were identified, 44 of which were included in this study as either reported pathogenic or likely causative in 42 patients from 36 families. The most common genes found to be likely causative for an autosomal dominant neuropathy were GDAP1 and GARS1. We also detected heterozygous likely pathogenic variants in DNA2, MFN2, DNM2, PDHA1, SDHA, and UCHL1. Biallelic variants in SACS, SPG7, GDAP1, C12orf65, UCHL1, NDUFS6, ETFDH and DARS2 and variants in the mitochondrial DNA (mtDNA)-encoded MT-ATP6 and MT-TK were also causative for mitochondrial CMT. Only 50% of these variants were already reported as solved in GPAP. CONCLUSION: Variants in mitochondrial disease genes are frequent in patients with inherited peripheral neuropathies. Due to the clinical overlap between mitochondrial disease and CMT, agnostic exome or genome sequencing have better diagnostic yields than targeted gene panels.

3.
Neurol India ; 72(1): 83-89, 2024 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-38443007

RESUMO

BACKGROUND: DM1 is a multisystem disorder caused by expansion of a CTG triplet repeat in the 3' non-coding region of DMPK. Neuropsychological consequences and sleep abnormalities are important associations in DM1. OBJECTIVE: To describe the clinical phenotype, disease progression and characterize the sleep alterations and cognitive abnormalities in a sub-set of patients. MATERIALS AND METHODS: A retrospective study on 120 genetically confirmed DM1 cases. Findings in neuropsychological assessment and multiple sleep questionnaires were compared with 14 age and sex matched healthy individuals. All 120 patients were contacted through letters/telephonic consultation/hospital visits to record their latest physical and functional disabilities. RESULTS: The mean age at symptom onset was 23.1 ± 11.4 years, M: F = 3.8:1, mean duration of illness = 14.3 ± 9.5 years. Clinically 54.2% had adult onset form, juvenile = 27.5%, infantile = 10.8%, late adult onset = 7.5%. Paternal transmission occurred more frequently. The predominant initial symptoms were myotonia (37.5%), hand weakness (21.7%), lower limb weakness (23.3%) and bulbar (10%). Twenty patients completed sleep questionnaires (SQ). Abnormal scores were noted in Epworth sleepiness scale (55%); Pittsburgh sleep quality index (45%); Berlin SQ (30%); Rapid eye movement sleep Behaviour Disorder SQ (15%); Restless leg syndrome rating scale (10%). Neuropsychological assessment of 20 patients revealed frontal executive dysfunction, attention impairment and visuospatial dysfunction. Frontal lobe was most affected (72%) followed by parietal (16%) and temporal lobe (12%). CONCLUSIONS: The current study provides a comprehensive account of the clinical characteristics in Indian patients with DM1. Hypersomnolence was most commonly seen. Excessive daytime sleepiness and Sleep disordered breathing were the most common sleep related abnormality. Cognitive impairment comprised predominantly of frontal lobe dysfunction.


Assuntos
Distúrbios do Sono por Sonolência Excessiva , Miotonia , Distrofia Miotônica , Adulto , Humanos , Criança , Adolescente , Adulto Jovem , Distrofia Miotônica/complicações , Estudos Retrospectivos , Progressão da Doença
4.
Neurol Genet ; 10(1): e200122, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38229919

RESUMO

Background and Objectives: Distal myopathies are a heterogeneous group of primary muscle disorders with recessive or dominant inheritance. ADSSL1 is a muscle-specific adenylosuccinate synthase isoform involved in adenine nucleotide synthesis. Recessive pathogenic variants in the ADSSL1 gene located in chromosome 14q32.33 cause a distal myopathy phenotype. In this study, we present the clinical and genetic attributes of 6 Indian patients with this myopathy. Methods: This was a retrospective study describing on Indian patients with genetically confirmed ADSSL1 myopathy. Details were obtained from the medical records. Results: All patients presented in their first or early second decade. All had onset in the first decade with a mean age at presentation being 17.7 ± 8.4 years (range: 3-27 years) and M:F ratio being 1:2. The mean disease duration was 9.3 ± 5.2 years ranging from 2 to 15 years. All patients were ambulant with wheelchair bound state in 1 patient due to respiratory involvement. The median serum creatine kinase (CK) level was 185.5 IU/L (range: 123-1564 IU/L). In addition to salient features of ptosis, cardiac involvement, bulbar weakness, and proximo-distal limb weakness with fatigue, there were significant seasonal fluctuations and decremental response to repetitive nerve stimulation, which have not been previously reported. Muscle histopathology was heterogenous with the presence of rimmed vacuoles, nemaline rods, intracellular lipid droplets along with chronic myopathic changes. Subtle response to pyridostigmine treatment was reported. While 5 of 6 patients had homozygous c.781G>A (p.Asp261Asn) variation, 1 had homozygous c.794G>A (p.Gly265Glu) in ADSSL1 gene. Discussion: This study expands the phenotypic spectrum and variability of ADSSL1 myopathy with unusual manifestations in this rare disorder. Because the variant c.781G>A (p.Asp261Asn) is the most common mutation among Indian patients similar to other Asian cohorts, this finding could be useful for genetic screening of suspected patients.

5.
Brain ; 147(1): 281-296, 2024 Jan 04.
Artigo em Inglês | MEDLINE | ID: mdl-37721175

RESUMO

Congenital myasthenic syndromes (CMS) are a rare group of inherited disorders caused by gene defects associated with the neuromuscular junction and potentially treatable with commonly available medications such as acetylcholinesterase inhibitors and ß2 adrenergic receptor agonists. In this study, we identified and genetically characterized the largest cohort of CMS patients from India to date. Genetic testing of clinically suspected patients evaluated in a South Indian hospital during the period 2014-19 was carried out by standard diagnostic gene panel testing or using a two-step method that included hotspot screening followed by whole-exome sequencing. In total, 156 genetically diagnosed patients (141 families) were characterized and the mutational spectrum and genotype-phenotype correlation described. Overall, 87 males and 69 females were evaluated, with the age of onset ranging from congenital to fourth decade (mean 6.6 ± 9.8 years). The mean age at diagnosis was 19 ± 12.8 (1-56 years), with a mean diagnostic delay of 12.5 ± 9.9 (0-49 years). Disease-causing variants in 17 CMS-associated genes were identified in 132 families (93.6%), while in nine families (6.4%), variants in genes not associated with CMS were found. Overall, postsynaptic defects were most common (62.4%), followed by glycosylation defects (21.3%), synaptic basal lamina genes (4.3%) and presynaptic defects (2.8%). Other genes found to cause neuromuscular junction defects (DES, TEFM) in our cohort accounted for 2.8%. Among the individual CMS genes, the most commonly affected gene was CHRNE (39.4%), followed by DOK7 (14.4%), DPAGT1 (9.8%), GFPT1 (7.6%), MUSK (6.1%), GMPPB (5.3%) and COLQ (4.5%). We identified 22 recurrent variants in this study, out of which eight were found to be geographically specific to the Indian subcontinent. Apart from the known common CHRNE variants p.E443Kfs*64 (11.4%) and DOK7 p.A378Sfs*30 (9.3%), we identified seven novel recurrent variants specific to this cohort, including DPAGT1 p.T380I and DES c.1023+5G>A, for which founder haplotypes are suspected. This study highlights the geographic differences in the frequencies of various causative CMS genes and underlines the increasing significance of glycosylation genes (DPAGT1, GFPT1 and GMPPB) as a cause of neuromuscular junction defects. Myopathy and muscular dystrophy genes such as GMPPB and DES, presenting as gradually progressive limb girdle CMS, expand the phenotypic spectrum. The novel genes MACF1 and TEFM identified in this cohort add to the expanding list of genes with new mechanisms causing neuromuscular junction defects.


Assuntos
Síndromes Miastênicas Congênitas , Masculino , Feminino , Humanos , Criança , Adolescente , Adulto Jovem , Adulto , Síndromes Miastênicas Congênitas/diagnóstico , Acetilcolinesterase , Diagnóstico Tardio , Junção Neuromuscular/genética , Testes Genéticos , Mutação/genética
6.
J Neurol ; 271(3): 1331-1341, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-37923938

RESUMO

The RASopathies are a group of genetic rare diseases caused by mutations affecting genes involved in the RAS/MAPK (RAS-mitogen activated protein kinase) pathway. Among them, PTPN11 pathogenic variants are responsible for approximately 50% of Noonan syndrome (NS) cases and, albeit to a lesser extent, of Leopard syndrome (LPRD1), which present a few overlapping clinical features, such as facial dysmorphism, developmental delay, cardiac defects, and skeletal deformities. Motor impairment and decreased muscle strength have been recently reported. The etiology of the muscle involvement in these disorders is still not clear but probably multifactorial, considering the role of the RAS/MAPK pathway in skeletal muscle development and Acetylcholine Receptors (AChR) clustering at the neuromuscular junction (NMJ). We report, herein, four unrelated children carrying three different heterozygous mutations in the PTPN11 gene. Intriguingly, their phenotypic features first led to a clinical suspicion of congenital myasthenic syndrome (CMS), due to exercise-induced fatigability with a variable degree of muscle weakness, and serum proteomic profiling compatible with a NMJ defect. Moreover, muscle fatigue improved after treatment with CMS-specific medication. Although the link between PTPN11 gene and neuromuscular transmission is unconfirmed, an increasing number of patients with RASopathies are affected by muscle weakness and fatigability. Hence, NS or LPDR1 should be considered in children with suspected CMS but negative genetic workup for known CMS genes or additional symptoms indicative of NS, such as facial dysmorphism or intellectual disability.


Assuntos
Síndromes Miastênicas Congênitas , Síndrome de Noonan , Criança , Humanos , Síndrome de Noonan/genética , Síndrome de Noonan/diagnóstico , Síndrome de Noonan/patologia , Síndromes Miastênicas Congênitas/genética , Proteômica , Mutação/genética , Fenótipo , Debilidade Muscular , Proteína Tirosina Fosfatase não Receptora Tipo 11/genética
7.
J Neuromuscul Dis ; 11(1): 221-232, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38108359

RESUMO

Charcot-Marie-Tooth disease 4H(CMT4H) is an autosomal recessive demyelinating form of CMT caused by FGD4/FRABIN mutations. CMT4H is characterized by early onset and slowly progressing motor and sensory deficits in the distal extremities, along with foot deformities. We describe a patient with CMT4H who presented with rapidly progressing flaccid quadriparesis during the postpartum period, which improved significantly with steroid therapy. Magnetic resonance imaging and ultrasonography demonstrated considerable nerve thickening with increased cross-sectional area in the peripheral nerves. A nerve biopsy revealed significant demyelination and myelin outfolding. This is the first report of an Indian patient with a novel homozygous nonsense c.1672C>T (p.Arg558Ter) mutation in the FGD4 gene, expanding the mutational and phenotypic spectrum of this disease.


Assuntos
Doença de Charcot-Marie-Tooth , Feminino , Humanos , Doença de Charcot-Marie-Tooth/genética , Doença de Charcot-Marie-Tooth/patologia , Proteínas dos Microfilamentos/genética , Linhagem , Mutação , Fenótipo , Fatores de Troca do Nucleotídeo Guanina/genética
8.
World Neurosurg ; 2023 Nov 23.
Artigo em Inglês | MEDLINE | ID: mdl-38006932

RESUMO

BACKGROUND: Hirayama disease (HD) is a cervical compressive myelopathy. Anterior cervical discectomy and fusion (ACDF) is identified as the best surgical approach. We evaluated surgical outcomes and factors influencing ACDF in HD. METHODS: Between 2015 and 2019, 126 patients with HD underwent ACDF. Contrast magnetic resonance imaging of the cervical spine in full flexion was performed. Clinical examination and preoperative/postoperative assessment of hand function using Fugl-Meyer assessment, Jebsen-Taylor hand function test, and handheld dynamometry were performed at 3-monthly intervals for 1 year. Surgical outcomes were assessed as per the Odom criteria and Hirayama outcome questionnaire. RESULTS: Age at onset and duration of illness were 12-31 years (mean, 18 ± 2.7) and 1-96 months (32.7 ± 24.4), respectively. All patients had progressive weakness and wasting of the affected limb. Cord atrophy was seen in 97.1%, with epidural detachment and engorgement of the posterior epidural venous plexus in all. All patients underwent ACDF. Of these patients, 54% had an excellent/good outcome and 39% had a satisfactory outcome as per the Odom scale at last follow-up (mean, 44.9 ± 16.5 months) after surgery. Handheld dynamometry showed improvement from preoperative values to 1 year follow-up. Duration of illness and age at onset had a negative correlation and the preoperative Fugl-Meyer score had a positive correlation with improvement. CONCLUSIONS: ACDF resulted in remarkable improvement or stabilization in neurologic deficits in many patients with HD. Because motor disability ensues over time, early surgical intervention during the progressive phase is advocated.

9.
Sci Rep ; 13(1): 15095, 2023 09 12.
Artigo em Inglês | MEDLINE | ID: mdl-37699968

RESUMO

Sarcoglycanopathy is the most frequent form of autosomal recessive limb-girdle muscular dystrophies caused by mutations in SGCB gene encoding beta-sarcoglycan proteins. In this study, we describe a shared, common haplotype co-segregating in 14 sarcoglycanopathy cases from 13 unrelated families from south Indian region with the likely pathogenic homozygous mutation c.544 T > G (p.Thr182Pro) in SGCB. Haplotype was reconstructed based on 10 polymorphic markers surrounding the c.544 T > G mutation in the cases and related family members as well as 150 unrelated controls from Indian populations using PLINK1.9. We identified haplotype H1 = G, A, G, T, G, G, A, C, T, G, T at a significantly higher frequency in cases compared to related controls and unrelated control Indian population. Upon segregation analysis within the family pedigrees, H1 is observed to co-segregate with c.544 T > G in a homozygous state in all the pedigrees of cases except one indicating a probable event of founder effect. Furthermore, Identical-by-descent and inbreeding coefficient analysis revealed relatedness among 33 new pairs of seemingly unrelated individuals from sarcoglycanopathy cohort and a higher proportion of homozygous markers, thereby indicating common ancestry. Since all these patients are from the south Indian region, we suggest this region to be a primary target of mutation screening in patients diagnosed with sarcoglycanopathy.


Assuntos
Sarcoglicanopatias , Sarcoglicanas , Humanos , Povo Asiático , Haplótipos , Mutação , Sarcoglicanopatias/genética , Sarcoglicanas/genética
10.
Intern Med J ; 2023 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-37578398

RESUMO

BACKGROUND: Kennedy disease (KD) is a slowly progressive lower motor neuron degenerative disease. The prevalence of KD is unknown in India. AIM: To describe the phenotypic and laboratory features of an Indian cohort of KD patients. METHODS: A retrospective study was done on seven genetically confirmed KD patients based on demographic, clinical and laboratory details. RESULTS: Mean age at onset and presentation was 37 ± 11.9 and 44.6 ± 13.5 years respectively. Progressive asymmetric proximal and distal limb weakness was the commonest symptom (57.1%). All patients had motor symptoms along with non-specific symptoms such as cramps from the onset. Easy fatigability, decremental response along with ptosis were noted in two patients, which was a novel finding. Gynaecomastia and tongue wasting with fasciculations were universal findings. All five patients with nerve conduction studies showed sensorimotor neuropathy. Magnetic resonance imaging muscle done in two patients showed a prominent moth-eaten appearance in the thigh and posterior leg compartment in one patient. The mean cytosine-adenine-guanine repeats were 44 ± 3.7, and there was no association between age of onset or severity with repeat length. Only one patient required an assistive device for ambulation after 15 years of symptom onset. CONCLUSIONS: This study showed phenotypic heterogeneity in the Indian cohort. The age of onset was earlier with a slowly progressive indolent course as compared with other ethnic cohorts. This highlights the importance of considering the KD diagnosis in patients with the indolent course and suspected ALS diagnosis even with ptosis and fatigability in an appropriate clinical context.

11.
J Neuromuscul Dis ; 10(4): 615-626, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37154180

RESUMO

BACKGROUND: The phenotypic spectrum of Fukutin-related protein (FKRP) mutations is highly variable and comprises of limb girdle muscular dystrophy (LGMD) R9 (previously LGMD 2I) and FKRP related congenital muscular dystrophies. OBJECTIVE: To identify the distinct genotype phenotype pattern in Indian patients with FKRP gene mutations. METHODS: We retrospectively reviewed the case files of patients with muscular dystrophy having a genetically confirmed FKRP mutation. All patients had undergone genetic testing using next-generation sequencing. RESULTS: Our patients included five males and four females presenting between 1.5 years and seven years of age (median age - 3 years). The initial symptom was a delayed acquisition of gross motor developmental milestones in seven patients and recurrent falls and poor sucking in one patient each. Two patients had a language delay, with both having abnormalities on the brain MRI. Macroglossia, scapular winging, and facial weakness were noted in one, three and four patients respectively. Calf muscle hypertrophy was seen in eight patients and ankle contractures in six. At the last follow-up, three patients had lost ambulation (median age - 7 years; range 6.5-9 years) and three patients had not attained independent ambulation. Creatine kinase levels ranged between 2793 and 32,396 U/L (mean 12,120 U/L). A common mutation - c.1343C>T was noted in 5 patients in our cohort. Additionally, four novel mutations were identified. Overall, six patients had an LGMD R9 phenotype, and three had a congenital muscular dystrophy phenotype. CONCLUSION: Patients with FKRP mutations can have varied presentations. A Duchenne-like phenotype was the most commonly encountered pattern in our cohort, with c.1343C>T being the most common mutation.


Assuntos
Distrofia Muscular do Cíngulo dos Membros , Distrofias Musculares , Masculino , Feminino , Humanos , Proteínas/genética , Proteínas/metabolismo , Pentosiltransferases/genética , Estudos Retrospectivos , Distrofias Musculares/genética , Distrofia Muscular do Cíngulo dos Membros/genética , Distrofia Muscular do Cíngulo dos Membros/metabolismo , Fenótipo , Genótipo
12.
J Neuromuscul Dis ; 10(4): 727-730, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37154181

RESUMO

Chronic progressive external ophthalmoplegia (CPEO) is symptom complex with progressive ptosis and restricted ocular motility without diplopia. MYH2 myopathy is rare disorder presenting with CPEO and muscle weakness. We report two Indian patients of MYH2 myopathy with unique features. Patient-1 presented with early adult-onset esophageal reflux followed by, proximal lower limb weakness, proptosis, CPEO without ptosis. He had elevated creatine kinase along with characteristic muscle MRI findings of prominent semitendinosus and medial gastrocnemius involvement. Patient -2 presented with early adult onset CPEO without limb weakness. His creatine kinase was normal. Both the patients had novel MYH2 mutations: a homozygous 5'splice variation in intron 4 (c.348 + 2dup) in patient 1 and homozygous single base pair deletion in exon 32 (p. Ala1480ProfsTer11) in patient 2. Unique features noted include adult onset, isolated CPEO, proptosis, esophageal reflux disease and absence of skeletal abnormalities. MYH2 myopathy has to be considered in adult patients with CPEO.


Assuntos
Blefaroptose , Exoftalmia , Doenças Musculares , Oftalmoplegia Externa Progressiva Crônica , Adulto , Humanos , Masculino , Creatina Quinase , Debilidade Muscular , Músculo Esquelético , Oftalmoplegia Externa Progressiva Crônica/genética
14.
J Neuromuscul Dis ; 10(2): 227-238, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36847014

RESUMO

BACKGROUND AND OBJECTIVE: Duchenne muscular dystrophy (DMD) is a degenerative X-linked muscle disease. Death frequently results from complications in cardiopulmonary systems. Preclinical/early diagnosis of cardiac autonomic abnormalities may aid initiate cardioprotective therapy and enhance prognosis. METHODS: A cross sectional, prospective study of 38 DMD boys compared with 37 age-matched healthy controls was conducted. Lead II electrocardiography and beat-to-beat blood pressure were recorded to assess heart rate variability (HRV), blood pressure variability (BPV), and baroreceptor sensitivity (BRS) in a standardized environment. Data were analysed and correlated with disease severity and genotype. RESULTS: In the DMD group, the median age at assessment was 8 years [IQR 7-9 years], the median age at disease onset was 3 years [IQR, 2-6 years], and the mean duration of illness was 4 years [IQR, 2.5-5]. DNA sequencing showed deletions in 34/38 (89.5 %) and duplications in 4/38 (10.5%) patients. The median heart rate in DMD children was significantly higher [101.19 (Range, 94.71-108.49)] /min compared to controls [81 (Range, 76.2-92.76)] /min (p < 0.05). All the assessed HRV and BPV parameters were significantly impaired in DMD cases except for the coefficient of variance of systolic blood pressure. Further, BRS parameters were also significantly reduced in DMD, excluding alpha-LF. A positive correlation was found between alpha HF with age at onset and duration of illness. CONCLUSION: This study demonstrates a distinct early impairment of neuro-cardio-autonomic regulation in DMD. Simple yet effective non-invasive techniques such as HRV, BPV, and BRS may help identify cardiac dysfunction in a pre-clinical state, paving the way for early cardio-protective therapies and limiting disease progression in DMD patients.


Assuntos
Distrofia Muscular de Duchenne , Masculino , Humanos , Criança , Estudos Transversais , Estudos Prospectivos , Coração , Sistema Nervoso Autônomo
15.
Nat Commun ; 14(1): 1009, 2023 02 23.
Artigo em Inglês | MEDLINE | ID: mdl-36823193

RESUMO

Mutations in the mitochondrial or nuclear genomes are associated with a diverse group of human disorders characterized by impaired mitochondrial respiration. Within this group, an increasing number of mutations have been identified in nuclear genes involved in mitochondrial RNA biology. The TEFM gene encodes the mitochondrial transcription elongation factor responsible for enhancing the processivity of mitochondrial RNA polymerase, POLRMT. We report for the first time that TEFM variants are associated with mitochondrial respiratory chain deficiency and a wide range of clinical presentations including mitochondrial myopathy with a treatable neuromuscular transmission defect. Mechanistically, we show muscle and primary fibroblasts from the affected individuals have reduced levels of promoter distal mitochondrial RNA transcripts. Finally, tefm knockdown in zebrafish embryos resulted in neuromuscular junction abnormalities and abnormal mitochondrial function, strengthening the genotype-phenotype correlation. Our study highlights that TEFM regulates mitochondrial transcription elongation and its defect results in variable, tissue-specific neurological and neuromuscular symptoms.


Assuntos
Fatores de Transcrição , Peixe-Zebra , Criança , Animais , Humanos , Fatores de Transcrição/genética , RNA Mitocondrial , Peixe-Zebra/genética , Peixe-Zebra/metabolismo , DNA Mitocondrial/genética , Transcrição Gênica , Mutação , Proteínas Mitocondriais/genética , Proteínas Mitocondriais/metabolismo
16.
Mol Neurobiol ; 60(5): 2602-2618, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-36692708

RESUMO

PPP1R21 acts as a co-factor for protein phosphatase 1 (PP1), an important serine/threonine phosphatase known to be essential for cell division, control of glycogen metabolism, protein synthesis, and muscle contractility. Bi-allelic pathogenic variants in PPP1R21 were linked to a neurodevelopmental disorder with hypotonia, facial dysmorphism, and brain abnormalities (NEDHFBA) with pediatric onset. Functional studies unraveled impaired vesicular transport as being part of PPP1R21-related pathomechanism. To decipher further the pathophysiological processes leading to the clinical manifestation of NEDHFBA, we investigated the proteomic signature of fibroblasts derived from the first NEDHFBA patient harboring a splice-site mutation in PPP1R21 and presenting with a milder phenotype. Proteomic findings and further functional studies demonstrate a profound activation of the ubiquitin-proteasome system with presence of protein aggregates and impact on cellular fitness and moreover suggest a cross-link between activation of the proteolytic system and cytoskeletal architecture (including filopodia) as exemplified on paradigmatic proteins including actin, thus extending the pathophysiological spectrum of the disease. In addition, the proteomic signature of PPP1R21-mutant fibroblasts displayed a dysregulation of a variety of proteins of neurological relevance. This includes increase proteins which might act toward antagonization of cellular stress burden in terms of pro-survival, a molecular finding which might accord with the presentation of a milder phenotype of our NEDHFBA patient.


Assuntos
Complexo de Endopeptidases do Proteassoma , Fala , Humanos , Actinas , Debilidade Muscular , Mutação/genética , Fenótipo , Proteína Fosfatase 1/genética , Proteômica
17.
Neuromuscul Disord ; 33(2): 161-168, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36634413

RESUMO

Primary acetylcholine receptor deficiency is the most common subtype of congenital myasthenic syndrome, resulting in reduced amount of acetylcholine receptors expressed at the muscle endplate and impaired neuromuscular transmission. AChR deficiency is caused mainly by pathogenic variants in the ε-subunit of the acetylcholine receptor encoded by CHRNE, although pathogenic variants in other subunits are also seen. We report the clinical and molecular features of 13 patients from nine unrelated kinships with acetylcholine receptor deficiency harbouring the CHRNA1 variant NM_001039523.3:c.257G>A (p.Arg86His) in homozygosity or compound heterozygosity. This variant results in the inclusion of an alternatively-spliced evolutionary exon (P3A) that causes expression of a non-functional acetylcholine receptor α-subunit. We compare the clinical findings of this group to the other cases of acetylcholine receptor deficiency within our cohort. We report differences in phenotype, highlighting a predominant pattern of facial and distal weakness in adulthood, predominantly in the upper limbs, which is unusual for acetylcholine receptor deficiency syndromes, and more in keeping with slow-channel syndrome or distal myopathy. Finally, we stress the importance of including alternative exons in variant analysis to increase the probability of achieving a molecular diagnosis.


Assuntos
Síndromes Miastênicas Congênitas , Receptores Nicotínicos , Humanos , Receptores Colinérgicos/genética , Receptores Colinérgicos/metabolismo , Síndromes Miastênicas Congênitas/genética , Síndromes Miastênicas Congênitas/patologia , Éxons/genética , Fenótipo , Mutação , Receptores Nicotínicos/genética
18.
Chronic Illn ; 19(2): 458-471, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-35469482

RESUMO

OBJECTIVE: To develop individualised psychosocial intervention program for people with MND and their families in India. METHODS: People with MND and healthcare staff were constructively involved in co-designing the intervention program in four phases adapted from the MRC framework: 1. A detailed need assessment phase where 30 participants shared their perceptions of psychosocial needs 2. Developing the intervention module (synthesis of narrative review, identified needs); 3. Feasibility testing of the intervention program among seven participants; 4. Feedback from participants on the feasibility (acceptance, practicality adaptation). The study adopted an exploratory research design. RESULTS: Intervention program of nine sessions, addressing psychosocial challenges through the different stages of progression of the illness and ways to handle the challenges, specific to the low resource settings, was developed and was found to be feasible. People with MND and families who participated in the feasibility study shared the perceived benefit through feedback interviews. CONCLUSION: MND has changing needs and challenges. Intervention programme was found to be feasible to be implemented among larger group to establish efficacy.


Assuntos
Esclerose Amiotrófica Lateral , Humanos , Intervenção Psicossocial
19.
Neurogenetics ; 24(1): 43-53, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36580222

RESUMO

Dysferlinopathies are a group of limb-girdle muscular dystrophies causing significant disability in the young population. There is a need for studies on large cohorts to describe the clinical, genotypic and natural history in our subcontinent. To describe and correlate the clinical, genetic profile and natural history of genetically confirmed dysferlinopathies. We analysed a retrospective cohort of patients with dysferlinopathy from a single quaternary care centre in India. A total of 124 patients with dysferlinopathy were included (40 females). Median age at onset and duration of illness were 21 years (range, 13-50) and 48 months (range, 8-288), respectively. The average follow-up period was 60 months (range, 12-288). Fifty-one percent had LGMD pattern of weakness at onset; 23.4% each had Miyoshi and proximo-distal type while isolated hyperCKemia was noted in 1.6%. About 60% were born to consanguineous parents and 26.6% had family history of similar illness. Twenty-three patients (18.6%) lost ambulation at follow-up; the median time to loss of independent ambulation was 120 months (range, 72-264). Single-nucleotide variants (SNVs) constituted 78.2% of patients; INDELs 14.5% and 7.3% had both SNVs and INDELs. Earlier age at onset was noted with SNVs. There was no correlation between the other clinical parameters and ambulatory status with the genotype. Thirty-seven (45.7%) novel pathogenic/likely pathogenic (P/LP) variants were identified out of a total of 81 variations. The c.3191G > A variant was the most recurrent mutation. Our cohort constitutes a clinically and genetically heterogeneous group of dysferlinopathies. There is no significant correlation between the clinico-genetic profile and the ambulatory status.


Assuntos
Distrofia Muscular do Cíngulo dos Membros , Feminino , Humanos , Estudos Retrospectivos , Distrofia Muscular do Cíngulo dos Membros/epidemiologia , Distrofia Muscular do Cíngulo dos Membros/genética , Distrofia Muscular do Cíngulo dos Membros/patologia , Mutação , Estudos de Associação Genética , Índia
20.
Neurol Res Pract ; 4(1): 49, 2022 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-36210472

RESUMO

BACKGROUND: We sought to determine the utility of PET-MRI in diagnosing Idiopathic Inflammatory Myositis (IIM), and look for association between FDG uptake and clinical, pathological and laboratory parameters. METHODS: A retrospective, observational study was conducted on IIM patients having positive serum autoantibodies and who underwent PET-MRI (3-Tesla SIEMENS Biograph MR scanner) between 2017 and 2021. Thirty patients who underwent PET-MRI to detect systemic metastasis without muscle involvement formed the control group. RESULTS: In the IIM cohort, female: male sex ratio was 1.73, mean age at diagnosis was 40.33 years, and the mean duration of illness was 7 months. 33.33% of patients had severe limb weakness. Mi2B (43.33%), Mi2A (43.33%), PL-7(10%), PL-12(6.67%), SRP (16.67%), Tif1gamma (3.33%), NxP2 (3.33%), Ro-52(40%), PM-Scl, U1-RNP, ANA (26.67%) were the serum autoantibodies identified. Using SUV max Ratio to quantify FDG uptake, PET-MRI showed a sensitivity of 100% with 93.3% specificity in diagnosing IIM.FDG uptake was maximum in proximal lower limb region followed by proximal upper limb. Multivariate regression analysis showed that the severity of muscle weakness, serum Mi2B antibody positivity and serum creatinine kinase levels had a significant positive correlation with FDG uptake (value of 0.005, 0.043, 0.042, respectively for whole-body FDG uptake). FDG uptake also showed good correlation with histopathological features and muscle MRI, but there was no significant association with treatment response. Three female patients in our cohort had primary malignancy involving the breast, uterus, and cervix. CONCLUSIONS: PET-MRI is a promising diagnostic modality for IIM. PET-MRI reflects the severity of muscle inflammation, showing good association with various clinical/laboratory parameters, histopathology, and muscle MRI. Parameters associated with severe muscle inflammation in PET-MRI-clinical severity of muscle weakness, Mi2B positivity, and serum creatine kinase levels-may be used as clinical/laboratory markers of disease severity in IIM. PET-MRI has the added advantage of detection of systemic malignancy.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...