Enfermedad de Charcot-Marie-Tooth: caracterización clínica, electrofisiológica y molecular en población Gallega

La enfermedad de Charcot-Marie-Tooth (CMT) es la neuropatía hereditaria más frecuente, con una prevalencia de 28 casos/100.000 habitantes. CMT es uno de los síndromes neurodegenerativos más complejos, con más de 80 genes identificados. OBJETIVO: Analizar la epidemiología genética de CMT en Galicia. Realizar una descripción fenotípica, electrofisiológica y molecular de la población con CMT en Galicia. Proponer un protocolo de diagnóstico genético para su aplicación en la práctica clínica. Estudio descriptivo de CMT en población adulta (>18 años) en Galicia. Se incluyen pacientes con CMT y seguimiento clínico en el servicio de Neurología de las diferentes Gerencias de Gestión. RESULTADOS: Identificamos 232 casos de CMT en Galicia (142 familias). La prevalencia de CMT fue de 10 casos/100.000 habitantes. La prevalencia de CMT desmielinizante fue de 6 casos/100.000 habitantes y para CMT axonal 3 casos/100.000 habitantes. El 60% de los casos mostró una herencia autosómica dominante y un 35% una herencia autosómica recesiva o fueron casos esporádicos. La causa más frecuente de CMT fue CMT1A (57%). Otras causas de CMT identificadas fueron CMTX1 (9%), CMT1B (7%), CMT2A (6%) y CMT2K (6%). Las formas desmielinizantes de CMT se agruparon en CMT1A (75%), CMT1B (9.2%), CMT4G (4%) y CMT1D (4%). En CMT2 observamos una amplia heterogeneidad clínica y genética, resultando CMT2A (26%), CMT2K (26%), CMTX1 (26%), mutaciones en BSCL2 (13%) y CMT2T (5.3%) las causas más frecuentes. Alcanzamos el diagnóstico molecular en el 93% de CMT desmielinizante y en un 47.5% de CMT axonal

Characterizing the phenotype and mode of inheritance of patients with inherited peripheral neuropathies carrying MME mutations

[EN] Background Mutations in the metalloendopeptidase (MME) gene were initially identified as a cause of autosomal recessive Charcot-Marie-Tooth disease type 2 (CMT2). Subsequently, variants in MME were linked to other late-onset autosomal dominant polyneuropathies. Thus, our goal was to define the phenotype and mode of inheritance of patients carrying changes in MME. Methods We screened 197 index cases with a hereditary neuropathy of the CMT type or distal hereditary motor neuropathy (dHMN) and 10 probands with familial amyotrophic lateral sclerosis (fALS) using a custom panel of 119 genes. In addition to the index case subjects, we also studied other clinically and/or genetically affected and unaffected family members. Results We found 17 variants in MME in a total of 20 index cases, with biallelic MME mutations detected in 13 cases from nine families (three in homozygosis and six in compound heterozygosis) and heterozygous variants found in 11 families. All patients with biallelic variants had a similar phenotype, consistent with late-onset axonal neuropathy. Conversely, the phenotype of patients carrying heterozygous mutations was highly variable [CMT type 1 (CMT1), CMT2, dHMN and fALS] and mutations did not segregate with the disease. Conclusion MME mutations that segregate in an autosomal recessive pattern are associated with a late-onset CMT2 phenotype, yet we could not demonstrate that MME variants in heterozygosis cause neuropathy. Our data highlight the importance of establishing an accurate genetic diagnosis in patients carrying MME mutations, especially with a view to genetic counselling.The authors thank the patients and healthy relatives for having participated in this project. We are grateful to the Eurobiobank CIBERER and the Biobank La Fe for their participation in the collection and processing of patient samples. We also thank the technicians at the Department of Genomics and Translational Genetics (CIPF) who participated in the quality control and processing of DNA samples (Virginia Rejas and Laura Ramírez), and the Bachelor¿s thesis student Andrea Ballester who helped with some clinical data collection. This project was funded by the Instituto de Salud Carlos III (ISCIII), FEDER (Grants no. PI12/00946 and PI16/00403 to TS, PI15/00187 to CE). MF holds a grant funded by the IIS La Fe (Grant no. 2015/0085). AS-M holds a grant funded by the Fundació Per Amor a l'Art (FPAA). JFV-C holds a ' Rio Hortega' contract funded by the ISCIII.Lupo, V.; Frasquet, M.; Sánchez-Monteagudo, A.; Pelayo-Negro, A.; García-Sobrino, T.; Sedano, MJ.; Pardo, J.... (2018). Characterizing the phenotype and mode of inheritance of patients with inherited peripheral neuropathies carrying MME mutations. Journal of Medical Genetics. 55(12):814-823. https://doi.org/10.1136/jmedgenet-2018-105650814823551

Characterizing SOD1 mutations in Spain. The impact of genotype, age, and sex in the natural history of the disease

11 páginas, 3 figuras, 2 tablasIntroduction: The aim of this study is to describe the frequency and distribution of SOD1 mutations in Spain, and to explore those factors contributing to their phenotype and prognosis. Methods: Seventeen centres shared data on amyotrophic lateral sclerosis (ALS) patients carrying pathogenic or likely pathogenic SOD1 variants. Multivariable models were used to explore prognostic modifiers. Results: In 144 patients (from 88 families), 29 mutations (26 missense, 2 deletion/insertion and 1 frameshift) were found in all 5 exons of SOD1, including 7 novel mutations. 2.6% of ALS patients (including 17.7% familial and 1.3% sporadic) were estimated to carry SOD1 mutations. Its frequency varied considerably between regions, due to founder events. The most frequent mutation was p.Gly38Arg (n = 58), followed by p.Glu22Gly (n = 11), p.Asn140His (n = 10), and the novel p.Leu120Val (n = 10). Most mutations were characterized by a protracted course, and some of them by atypical phenotypes. Older age of onset was independently associated with faster disease progression (exp(Estimate) = 1.03 [0.01, 0.05], p = 0.001) and poorer survival (HR = 1.05 [1.01, 1.08], p = 0.007), regardless of the underlying mutation. Female sex was independently associated to faster disease progression (exp(Estimate) = 2.1 [1.23, 3.65], p = 0.012) in patients carrying the p.Gly38Arg mutation, resulting in shorter survival compared with male carriers (236 vs 301 months). Conclusions: These data may help to evaluate the efficacy of SOD1 targeted treatments, and to expand the number of patients that might benefit from these treatments.This study has received funding from: Instituto de Salud Carlos III (21/00737 PI J.F.V.C., 19/01178 PI T.S., PI 19/01543 to R.R.), cofunded by European Regional Development Fund (‘A way to make Europe’); STOPELA (2017/0653); I + D biomedicina 2017 from Comunidad de Madrid ‘ELA-Madrid’ (B2017/BMD-3813 to A.G.-R.); estrategias frente a Enfermedades Neurodegenerativas Ministerio de Sanidad – Comunidad de Madrid B.O.C.M. Num. 142 - Lunes 17 de junio de 2019 - Pág. 10 ‘Estudio genético de la población con ELA de la Comunidad de Madrid’ to A.G.-R. The Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER) and the Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas (CIBERNED) are initiatives from the ISCIII. J.F.V.C., T.S., C.P., M.P., R.R.-G., J.T.S. and R.J.M. are members of the European Reference Network for Rare Neuromuscular Diseases (ERN EURO-NMD). The funders had no role in the design and conduct of the study; collection, management, analysis, and interpretation of the data; preparation, review, or approval of the manuscript; and decision to submit the manuscript for publication.Peer reviewe

Methylene Blue functionalized carbon nanodots combined with different shape gold nanostructures for sensitive and selective SARS-CoV-2 sensing

The development of DNA-sensing platforms based on new synthetized Methylene Blue functionalized carbon nanodots combined with different shape gold nanostructures (AuNs), as a new pathway to develop a selective and sensitive methodology for SARS-CoV-2 detection is presented. A mixture of gold nanoparticles and gold nanotriangles have been synthetized to modify disposable electrodes that act as an enhanced nanostructured electrochemical surface for DNA probe immobilization. On the other hand, modified carbon nanodots prepared a la carte to contain Methylene Blue (MB-CDs) are used as electrochemical indicators of the hybridization event. These MB-CDs, due to their structure, are able to interact differently with double and single-stranded DNA molecules. Based on this strategy, target sequences of the SARS-CoV-2 virus have been detected in a straightforward way and rapidly with a detection limit of 2.00 aM. Moreover, this platform allows the detection of the SARS-CoV-2 sequence in the presence of other viruses, and also a single nucleotide polymorphism (SNPs). The developed approach has been tested directly on RNA obtained from nasopharyngeal samples from COVID-19 patients, avoiding any amplification process. The results agree well with those obtained by RT-qPCR or reverse transcription quantitative polymerase chain reaction technique.We acknowledge the support from the Comunidad de Madrid (TRANSNANOAVANSENS-CM, S2018/NMT-4349, NANOCOV-CM, SI3/PJI/2021–00341) and Ministerio de economia y competitividad de España (PID2020–116728RB-100, CTQ2015–71955-REDT (ELECTROBIONET)). IMDEA Nanociencia acknowledges support from the Programme for Centres of Excellence in R&D ‘Severo Ochoa’ (CEX2020–001039-S, MINECO). Authors also acknowledge REACT EU NANOCOV-CM project. RdC acknowledges support from Fundación IMDEA Nanociencia, Banco Santander, UAM (convocatoria CRUE- SANTANDER-CSIC, reference 10.01.03.02.41).Peer reviewe

Drug-refractory myasthenia gravis : Clinical characteristics, treatments, and outcome

Altres ajuts: R. Alvarez-Velasco was supported by grant SLT008/18/00207 from the Health Research and Innovation Strategic Plan (PERIS). The NMD-ES Project and F. PlaJunca (data curator) are partially funded by the Centro de Investigacion Biomédica en Red de Enfermedades Raras (CIBERER).To describe the clinical characteristics and outcomes in patients with refractory myasthenia gravis (MG) and to determine the effectiveness and side effects of the drugs used for their treatment. This observational retrospective cross-sectional multicenter study was based on data from the Spanish MG Registry (NMD-ES). Patients were considered refractory when their MG Foundation of America post-interventional status (MGFA-PIS) was unchanged or worse after corticosteroids and two or more other immunosuppressive agents. Clinical and immunologic characteristics of drug-refractory patients, efficiency and toxicity of drugs used, and outcome (MGFA-PIS) at end of follow-up were studied. We included 990 patients from 15 hospitals. Eighty-four patients (68 of 842 anti-acetylcholine receptor [AChR], 5 of 26 anti-muscle-specific tyrosine kinase [MusK], 10 of 120 seronegative, and 1 of 2 double-seropositive patients) were drug refractory. Drug-refractory patients were more frequently women (p < 0.0001), younger at onset (p < 0.0001), and anti-MuSK positive (p = 0.037). Moreover, they more frequently presented a generalized form of the disease, bulbar symptoms, and life-threatening events (p < 0.0001; p = 0.018; and p = 0.002, respectively) than non-drug-refractory patients. Mean follow-up was 9.8 years (SD 4.5). Twenty-four (50%) refractory patients had side effects to one or more of the drugs. At the end of follow-up, 42.9% of drug-refractory patients (42.6% of anti-AChR, 100% of anti-MuSK, and 10% of seronegative patients) and 79.8% of non-drug-refractory patients (p < 0.0001) achieved remission or had minimal manifestations. Eighty percent of drug-refractory-seronegative patients did not respond to any drug tested. In this study, 8.5% of MG patients were drug-refractory. New more specific drugs are needed to treat drug-refractory MG patients

Distribution and genotype-phenotype correlation of GDAP1 mutations in Spain

Mutations in the GDAP1 gene can cause Charcot-Marie-Tooth disease. These mutations are quite rare in most Western countries but not so in certain regions of Spain or other Mediterranean countries. This cross-sectional retrospective multicenter study analyzed the clinical and genetic characteristics of patients with GDAP1 mutations across Spain. 99 patients were identified, which were distributed across most of Spain, but especially in the Northwest and Mediterranean regions. The most common genotypes were p.R120W (in 81% of patients with autosomal dominant inheritance) and p.Q163X (in 73% of autosomal recessive patients). Patients with recessively inherited mutations had a more severe phenotype, and certain clinical features, like dysphonia or respiratory dysfunction, were exclusively detected in this group. Dominantly inherited mutations had prominent clinical variability regarding severity, including 29% of patients who were asymptomatic. There were minor clinical differences between patients harboring specific mutations but not when grouped according to localization or type of mutation. This is the largest clinical series to date of patients with GDAP1 mutations, and it contributes to define the genetic distribution and genotype-phenotype correlation in this rare form of CMT

Autoantibody screening in Guillain-Barré syndrome

Background: Guillain?Barré syndrome (GBS) is an acute inflammatory neuropathy with a heterogeneous presentation. Although some evidences support the role of autoantibodies in its pathogenesis, the target antigens remain unknown in a substantial proportion of GBS patients. The objective of this study is to screen for autoantibodies targeting peripheral nerve components in Guillain-Barré syndrome. Methods: Autoantibody screening was performed in serum samples from all GBS patients included in the International GBS Outcome study by 11 different Spanish centres. The screening included testing for anti-ganglioside antibodies, anti-nodo/paranodal antibodies, immunocytochemistry on neuroblastoma-derived human motor neurons and murine dorsal root ganglia (DRG) neurons, and immunohistochemistry on monkey peripheral nerve sections. We analysed the staining patterns of patients and controls. The prognostic value of anti-ganglioside antibodies was also analysed. Results: None of the GBS patients (n = 100) reacted against the nodo/paranodal proteins tested, and 61 (61%) were positive for, at least, one anti-ganglioside antibody. GBS sera reacted strongly against DRG neurons more frequently than controls both with IgG (6% vs 0%; p = 0.03) and IgM (11% vs 2.2%; p = 0.02) immunodetection. No differences were observed in the proportion of patients reacting against neuroblastoma-derived human motor neurons. Reactivity against monkey nerve tissue was frequently detected both in patients and controls, but specific patterns were only detected in GBS patients: IgG from 13 (13%) patients reacted strongly against Schwann cells. Finally, we confirmed that IgG anti-GM1 antibodies are associated with poorer outcomes independently of other known prognostic factor

Proceso asistencial integrado de esclerosis lateral amiotrófica

O proceso asistencial integrado da esclerose lateral amiotrófica, elaborouse co obxectivo de crear un proceso de traballo común en todas as áreas para facilitar a asistencia sanitaria ás persoas diagnosticadas desta enfermidade. Establécense actuacións como o asesoramento continuo, as consultas en acto único, a coordinación asistencial, tanto entre especialidades como coa atención primaria e a coordinación administrativa do sistema socio sanitario. Neste proceso participaron profesionais das diferentes áreas sanitarias especialistas en neuroloxía, endocrinoloxía, neumoloxía, psicoloxía clínica, rehabilitación, traballo social e hospitalización a domicilioEl proceso asistencial integrado de la esclerosis lateral amiotrófica, se elaboró con el objetivo de crear un proceso de trabajo común en todas las áreas para facilitar la asistencia sanitaria a las personas diagnosticadas de esta enfermedad. Se establecen actuaciones como el asesoramiento continuo, las consultas en acto único, la coordinación asistencial, tanto entre especialidades como con la atención primaria y la coordinación administrativa del sistema socio sanitario. En este proceso participaron profesionales de las diferentes áreas sanitarias especialistas en neurología, endocrinología, neumología, psicología clínica, rehabilitación, trabajo social y hospitalización a domicili