Lorenzo Nanetti
@istituto-besta.it
Fondazione IRCCS Istituto Neurologico Carlo Besta
Scopus Publications
Scopus Publications
Thiago Junqueira Ribeiro Rezende, Isaac Adanyaguh, Orlando G P Barsottini, Benjamin Bender, Fernando Cendes, Leo Coutinho, Andreas Deistung, Imis Dogan, Alexandra Durr, Juan Fernandez-Ruiz,et al.
BMJ
BackgroundSpinal cord damage is a feature of many spinocerebellar ataxias (SCAs), but well-powered in vivo studies are lacking and links with disease severity and progression remain unclear. Here we characterise cervical spinal cord morphometric abnormalities in SCA1, SCA2, SCA3 and SCA6 using a large multisite MRI dataset.MethodsUpper spinal cord (vertebrae C1–C4) cross-sectional area (CSA) and eccentricity (flattening) were assessed using MRI data from nine sites within the ENIGMA-Ataxia consortium, including 364 people with ataxic SCA, 56 individuals with preataxic SCA and 394 nonataxic controls. Correlations and subgroup analyses within the SCA cohorts were undertaken based on disease duration and ataxia severity.ResultsIndividuals in the ataxic stage of SCA1, SCA2 and SCA3, relative to non-ataxic controls, had significantly reduced CSA and increased eccentricity at all examined levels. CSA showed large effect sizes (d>2.0) and correlated with ataxia severity (r<−0.43) and disease duration (r<−0.21). Eccentricity correlated only with ataxia severity in SCA2 (r=0.28). No significant spinal cord differences were evident in SCA6. In preataxic individuals, CSA was significantly reduced in SCA2 (d=1.6) and SCA3 (d=1.7), and the SCA2 group also showed increased eccentricity (d=1.1) relative to nonataxic controls. Subgroup analyses confirmed that CSA and eccentricity are abnormal in early disease stages in SCA1, SCA2 and SCA3. CSA declined with disease progression in all, whereas eccentricity progressed only in SCA2.ConclusionsSpinal cord abnormalities are an early and progressive feature of SCA1, SCA2 and SCA3, but not SCA6, which can be captured using quantitative MRI.
Luca Porcu, Mario Fichera, Lorenzo Nanetti, Eliana Rulli, Paola Giunti, Michael H. Parkinson, Alexandra Durr, Claire Ewenczyk, Sylvia Boesch, Wolfgang Nachbauer,et al.
Wiley
AbstractBackgroundThe Scale for Assessment and Rating of Ataxia (SARA) is widely used in different types of ataxias and has been chosen as the primary outcome measure in the European natural history study for Friedreich ataxia (FA).MethodsTo assess distribution and longitudinal changes of SARA scores and its single items, we analyzed SARA scores of 502 patients with typical‐onset FA (<25 years) participating in the 4‐year prospective European FA Consortium for Translational Studies (EFACTS). Pattern of disease progression was determined using linear mixed‐effects regression models. The chosen statistical model was re‐fitted in order to estimate parameters and predict disease progression. Median time‐to‐change and rate of score progression were estimated using the Kaplan–Meier method and weighted linear regression models, respectively.ResultsSARA score at study enrollment and age at onset were the major predictive factors of total score progression during the 4‐year follow‐up. To a less extent, age at evaluation also influenced the speed of SARA progression, while disease duration did not improve the prediction of the statistical model. Temporal dynamics of total SARA and items showed a great variability in the speed of score increase during disease progression. Gait item had the highest annual progression rate, with median time for one‐point score increase of 1 to 2 years.InterpretationAnalyses of statistical properties of SARA suggest a variable sensitivity of the scale at different disease stages, and provide important information for population selection and result interpretation in future clinical trials.
Anna Castaldo, Mariangela Farinotti, Mario Fichera, Lorenzo Nanetti, Filippo Fortuna, Caterina Mariotti, and Alessandra Solari
Springer Science and Business Media LLC
Paulina Cunha, Emilien Petit, Marie Coutelier, Giulia Coarelli, Caterina Mariotti, Jennifer Faber, Judith Van Gaalen, Joana Damasio, Zofia Fleszar, Michele Tosi,et al.
Elsevier BV
Lorenzo Nanetti, Stefania Magri, Mario Fichera, Anna Castaldo, Anna Nigri, Chiara Pinardi, Alessia Mongelli, Lidia Sarro, Davide Pareyson, Marina Grisoli,et al.
Wiley
BACKGROUND AND OBJECTIVES
Spinocerebellar ataxias (SCAs) are autosomal dominant disorders with extensive clinical and genetic heterogeneity. We recently identified a form of SCA transmitted with a digenic pattern of inheritance caused by the concomitant presence of an intermediate-length expansion in TATA-box binding protein gene (TBP40-46 ) and a heterozygous pathogenic variant in the Stip1-homologous and U-Box containing protein 1 gene (STUB1). This SCATBP/STUB1 represents the first example of a cerebellar disorder in which digenic inheritance has been identified.
OBJECTIVES
We studied a large cohort of patients with SCATBP/STUB1 with the aim of describing specific clinical and neuroimaging features of this distinctive genotype.
METHODS
In this observational study, we recruited 65 affected and unaffected family members from 21 SCATBP/STUB1 families and from eight families with monogenic SCA17. Their characteristics and phenotypes were compared with those of 33 age-matched controls.
RESULTS
SCATBP/STUB1 patients had multi-domain dementia with a more severe impairment in respect to patient carrying only fully expanded SCA17 alleles. Cerebellar volume and thickness of cerebellar cortex were reduced in SCATBP/STUB1 compared with SCA17 patients (P = 0.03; P = 0.008). Basal ganglia volumes were reduced in both patient groups, as compared with controls, whereas brainstem volumes were significantly reduced in SCATBP/STUB1 , but not in SCA17 patients.
CONCLUSIONS
The identification of the complex SCATBP/STUB1 phenotype may impact on diagnosis and genetic counseling in the families with both hereditary and sporadic ataxia. The independent segregation of TBP and STUB1 alleles needs to be considered for recurrence risk and predictive genetic tests. © 2023 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.
Serena Santangelo, Patrizia Bossolasco, Stefania Magri, Claudia Colombrita, Sabrina Invernizzi, Cinzia Gellera, Lorenzo Nanetti, Daniela Di Bella, Vincenzo Silani, Franco Taroni,et al.
Elsevier BV
Elisabetta Indelicato, Kathrin Reetz, Sarah Maier, Wolfgang Nachbauer, Matthias Amprosi, Paola Giunti, Caterina Mariotti, Alexandra Durr, Francisco J.R. de Rivera Garrido, Thomas Klopstock,et al.
Wiley
ABSTRACTBackgroundFriedreich's ataxia (FA) is a rare multisystemic disorder which can cause premature death.ObjectivesTo investigate predictors of survival in FA.MethodsWithin a prospective registry established by the European Friedreich's Ataxia Consortium for Translational Studies (EFACTS; ClinicalTrials.gov identifier NCT02069509) we enrolled genetically confirmed FA patients at 11 tertiary centers and followed them in yearly intervals. We investigated overall survival applying the Kaplan–Meier method, life tables, and log‐rank test. We explored prognostic factors applying Cox proportional hazards regression and subsequently built a risk score which was assessed for discrimination and calibration performance.ResultsBetween September 2010 and March 2017, we enrolled 631 FA patients. Median age at inclusion was 31 (range, 6–76) years. Until December 2022, 44 patients died and 119 terminated the study for other reasons. The 10‐year cumulative survival rate was 87%. In a multivariable analysis, the disability stage (hazard ratio [HR] 1.51, 95% CI 1.08–2.12, P = 0.02), history of arrhythmic disorder (HR 2.93, 95% CI 1.34–6.39, P = 0.007), and diabetes mellitus (HR 2.31, 95% CI 1.05–5.10, P = 0.04) were independent predictors of survival. GAA repeat lengths did not improve the survival model. A risk score built on the previously described factors plus the presence of left ventricular systolic dysfunction at echocardiography enabled identification of four trajectories to prognosticate up to 10‐year survival (log‐rank test P < 0.001).ConclusionsArrhythmias, progressive neurological disability, and diabetes mellitus influence the overall survival in FA. We built a survival prognostic score which identifies patients meriting closer surveillance and who may benefit from early invasive cardiac monitoring and therapy. © 2023 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.
Nicola Rifino, Anna Bersano, Alessandro Padovani, Giancarlo Maria Conti, Anna Cavallini, Luca Colombo, Alberto Priori, Raffaella Pianese, Maria Rosaria Gammone, Alessandra Erbetta,et al.
Springer Science and Business Media LLC
Giulia Ferrera, Rossella Izzo, daniele ghezzi, Lorenzo Nanetti, Eleonora Lamantea, and Anna Ardissone
Georg Thieme Verlag KG
Spinocerebellar ataxias (SCAs) are heterogeneous autosomal dominant progressive ataxic disorders. SCA25 has been linked to PNPT1 pathogenic variants. Although pediatric onset is not unusual, to date only one patient with onset in the first years of life has been reported. This study presents an additional case, wherein symptoms emerged during the toddler phase, accompanied by the identification of a novel PNPT1 variant. The childwas seen at 3 years because of frequent falls. Neurological examination revealed cerebellar signsand psychomotor delay. Brain MRI showed cerebellar atrophy (CA), cerebellar cortex and dentate nuclei hyperintensities. Metabolic and genetic testing was inconclusive. At follow up (age 6), the child had clinically and radiologically worsened; ENG revealed axonal sensory neuropathy. Screening of genes associated with ataxias and mitochondrial disease identified a novel, heterozygous variant in PNPT1, which was probably pathogenic. This variant was also detected in the proband’s mother and maternal grandmother both asymptomatic, which aligns with the previously documented incomplete penetrance of heterozygous PNPT1 variants. Our study confirms that SCA25 can have onset in early-childhood and characterizes natural history in pediatric cases: progressive cerebellar ataxia, sensory neuropathy which manifests during the course of the disease. We report for the first time cerebellar gray matter hyperintensities, suggesting that SCA25 should be included in the differential diagnosis of cerebellar ataxias associated with such brain imaging features. In summary, SCA25 should be considered in the diagnostic workup of early onset pediatric progressive ataxias Additionally, we confirm an incomplete penetrance and highly variable expressivity of PNPT1-associated SCA25.
Lorenzo Nanetti, Mary Kearney, Sylvia Boesch, Lucie Stovickova, Juan Darío Ortigoza-Escobar, Alfons Macaya, David Gomez-Andres, Emmanuel Roze, Maria-Judit Molnar, Nicole I. Wolf,et al.
Springer Science and Business Media LLC
Gülin Öz, Sirio Cocozza, Pierre-Gilles Henry, Christophe Lenglet, Andreas Deistung, Jennifer Faber, Adam J. Schwarz, Dagmar Timmann, Koene R. A. Van Dijk, Ian H. Harding,et al.
Springer Science and Business Media LLC
Caterina Mariotti, Mario Fichera, and Lorenzo Nanetti
Springer International Publishing
Mischa Uebachs, Philipp Wegner, Sebastian Schaaf, Simon Kugai, Heike Jacobi, Sheng-Han Kuo, Tetsuo Ashizawa, Juliane Fluck, Sophie Tezenas du Montcel, Peter Bauer,et al.
Springer Science and Business Media LLC
AbstractWith SCAview, we present a prompt and comprehensive tool that enables scientists to browse large datasets of the most common spinocerebellar ataxias intuitively and without technical effort. Basic concept is a visualization of data, with a graphical handling and filtering to select and define subgroups and their comparison. Several plot types to visualize all data points resulting from the selected attributes are provided. The underlying synthetic cohort is based on clinical data from five different European and US longitudinal multicenter cohorts in spinocerebellar ataxia type 1, 2, 3, and 6 (SCA1, 2, 3, and 6) comprising > 1400 patients with overall > 5500 visits. First, we developed a common data model to integrate the clinical, demographic, and characterizing data of each source cohort. Second, the available datasets from each cohort were mapped onto the data model. Third, we created a synthetic cohort based on the cleaned dataset. With SCAview, we demonstrate the feasibility of mapping cohort data from different sources onto a common data model. The resulting browser-based visualization tool with a thoroughly graphical handling of the data offers researchers the unique possibility to visualize relationships and distributions of clinical data, to define subgroups and to further investigate them without any technical effort. Access to SCAview can be requested via the Ataxia Global Initiative and is free of charge.
Christian Hohenfeld, Ulrich Terstiege, Imis Dogan, Paola Giunti, Michael H. Parkinson, Caterina Mariotti, Lorenzo Nanetti, Mario Fichera, Alexandra Durr, Claire Ewenczyk,et al.
Springer Science and Business Media LLC
AbstractWe explored whether disease severity of Friedreich ataxia can be predicted using data from clinical examinations. From the database of the European Friedreich Ataxia Consortium for Translational Studies (EFACTS) data from up to five examinations of 602 patients with genetically confirmed FRDA was included. Clinical instruments and important symptoms of FRDA were identified as targets for prediction, while variables such as genetics, age of disease onset and first symptom of the disease were used as predictors. We used modelling techniques including generalised linear models, support-vector-machines and decision trees. The scale for rating and assessment of ataxia (SARA) and the activities of daily living (ADL) could be predicted with predictive errors quantified by root-mean-squared-errors (RMSE) of 6.49 and 5.83, respectively. Also, we were able to achieve reasonable performance for loss of ambulation (ROC-AUC score of 0.83). However, predictions for the SCA functional assessment (SCAFI) and presence of cardiological symptoms were difficult. In conclusion, we demonstrate that some clinical features of FRDA can be predicted with reasonable error; being a first step towards future clinical applications of predictive modelling. In contrast, targets where predictions were difficult raise the question whether there are yet unknown variables driving the clinical phenotype of FRDA.
Davide Rossi Sebastiano, Daniele Cazzato, Elisa Visani, Eleonora Dalla Bella, Laura Brambilla, Grazia Devigili, Paola Caroppo, Lorenzo Maggi, Lorenzo Nanetti, Ettore Salsano,et al.
Springer Science and Business Media LLC
Nicole Pizzorni, Andrea Ciammola, Giovanni Casazza, Daniela Ginocchio, Federica Bianchi, Sarah Feroldi, Barbara Poletti, Lorenzo Nanetti, Caterina Mariotti, Gabriele Mora,et al.
Wiley
BACKGROUND
Oropharyngeal dysphagia is generally recognized to increase the risk of malnutrition, however, its role in patients with neurodegenerative disease has still to be determined. The cross-sectional study aimed to investigate the impact of swallowing function on malnutrition risk in patients with neurodegenerative diseases.
METHODS
Patients with oral nutrition and diagnosis of Huntington's disease (HD), Parkinson's disease (PD), or Amyotrophic Lateral Sclerosis (ALS) were recruited. Demographic and clinical data were collected. The swallowing assessment included a fiberoptic endoscopic evaluation of swallowing, an oral phase assessment, and a meal observation scored with the Mealtime Assessment Scale (MAS). Malnutrition risk was assessed with the Mini Nutritional Assessment (MNA®).
RESULTS
Overall, 148 patients were recruited (54 HD, 33 PD, and 61 ALS). One-hundred (67.6%) patients were considered at risk of malnutrition. At the multivariate analysis, age ≥65 (OR 3.16, p=0.014), disease severity (moderate vs mild OR 3.89, severe vs mild OR 9.71, p=0.003), number of masticatory cycles (OR 1.03, p=0.044), and MAS safety (OR 1.44, p=0.016) were significantly associated with malnutrition risk.
CONCLUSION
Prolonged oral phase and signs of impaired swallowing safety during meals, together with older age and disease severity, are independent predictors of malnutrition risk in neurodegenerative diseases. The study broadens the focus on dysphagia, stressing the importance of an early detection not only of pharyngeal signs, but also of oral phase impairment and meal difficulties through a multidimensional swallowing assessment.
Anna Nigri, Lidia Sarro, Alessia Mongelli, Anna Castaldo, Luca Porcu, Chiara Pinardi, Marina Grisoli, Stefania Ferraro, Laura Canafoglia, Elisa Visani,et al.
Springer Science and Business Media LLC
Spinocerebellar ataxias type 1 (SCA1) is an autosomal dominant disease usually manifesting in adulthood. We performed a prospective 1-year longitudinal study in 14 presymptomatic mutation carriers (preSCA1), 11 ataxic patients, and 21 healthy controls. SCA1 patients had a median disease duration of 6 years (range 2-16) and SARA score of 7 points (range 3.5-20). PreSCA1 had an estimated time before disease onset of 9.7 years (range 4-30), and no signs of ataxia. At baseline, SCA1 patients significantly differed from controls in SARA score (Scale for Assessment and Rating of Ataxia), cognitive tests, and structural MRI measures. Significant volume loss was found in cerebellum, brainstem, basal ganglia, and cortical thinning in frontal, temporal, and occipital regions. PreSCA1 did not differ from controls. At 1-year follow-up, SCA1 patients showed significant increase in SARA score, and decreased volume of cerebellum (- 0.6%), pons (- 5.5%), superior cerebellar peduncles (- 10.7%), and midbrain (- 3.0%). Signs of disease progression were also observed in preSCA1 subjects, with increased SARA score and reduced total cerebellar volume. Our exploratory study suggests that clinical scores and MRI measures provide valuable data to monitor and quantify the earliest changes associated with the preclinical and the symptomatic phases of SCA1 disease.
Lorenzo Nanetti, Daniela Di Bella, Stefania Magri, Mario Fichera, Elisa Sarto, Anna Castaldo, Alessia Mongelli, Silvia Baratta, Silvia Fenu, Marco Moscatelli,et al.
Frontiers Media SA
A wide spectrum of neurodegenerative diseases has been associated with pathogenic variants in the PNPLA6 (patatin-like phospholipase domain-containing protein 6) gene, including spastic paraplegia type 39, Gordon—Holmes, Boucher—Neuhauser, Oliver—Mc Farlane, and Laurence—Moon syndromes. These syndromes present variable and overlapping clinical symptoms, encompassing cerebellar ataxia, hypogonadotropic hypogonadism, chorioretinal dystrophy, spastic paraplegia, muscle wasting, peripheral neuropathy, and cognitive impairment. In the present study, we performed a wide genetic screening in 292 patients presenting with ataxia or spastic paraplegia using a probe-based customized gene panel, covering &gt;200 genes associated with spinocerebellar diseases. We identified six novel and four recurrent PNPLA6 gene variants in eight patients (2.7%). Six patients presented an infantile or juvenile onset (age &lt;18), and two patients had an adult onset. Cerebellar ataxia was observed in seven patients and spastic paraplegia in one patient. Progression of cerebellar symptoms was slow in all patients, who retained ambulation even after a mean disease duration of 15 years. Brain MRI showed cerebellar atrophy in 6/8 patients, more pronounced in superior and dorsal vermis lobules (I to VII). Additional clinical features included hypogonadotropic hypogonadism (5/8), growth hormone deficiency (2/8), peripheral axonal neuropathy (4/8), cognitive impairment (3/8), chorioretinal dystrophy (2/8), and bilateral vestibular areflexia with a reduced visual vestibule-ocular reflex (1/8). In accordance with previous studies, chorioretinal dystrophy was the most frequent presenting symptom in early onset patients, hypogonadotropic hypogonadism in juvenile onset cases, and cerebellar ataxia in adult patients. One patient had an initial clinical presentation compatible with Cerebellar Ataxia with Neuropathy and Vestibular Areflexia Syndrome (CANVAS), but no pathological expansions in the RFC1 gene. In conclusion, patients with PNPLA6 variants present a variable age of onset spanning from infancy to adulthood, and each clinical symptom has an age-dependent manifestation thus requiring a multi-systemic diagnostic approach. The description of patients presenting very late-onset cerebellar ataxia suggests that PNPLA6 genetic screening should also be considered in the diagnostic workout of adult cerebellar ataxia.
Stefania Magri, Lorenzo Nanetti, Cinzia Gellera, Elisa Sarto, Elena Rizzo, Alessia Mongelli, Benedetta Ricci, Roberto Fancellu, Luisa Sambati, Pietro Cortelli,et al.
Elsevier BV
Marta Gatti, Stefania Magri, Daniela Di Bella, Elisa Sarto, Franco Taroni, Caterina Mariotti, and Lorenzo Nanetti
Springer Science and Business Media LLC
Spastic paraplegia type 46 (SPG46) is a rare autosomal recessive hereditary spastic paraplegia, caused by mutations in the non-lysosomal glucosylceramidase β2 (GBA2) gene. Worldwide, approximately twenty SPG46 families have been identified so far. We describe a compound heterozygous Italian patient carrying a novel (p.Arg879Gln) and a recurrent (p.Arg399 *) GBA2 gene variant. The patient presented unsteady gait at age 2, and progressively manifested spastic-ataxia, scoliosis, mild intellectual decline, and bilateral cataract. Clinical manifestations associated with GBA2 gene variants encompass a spectrum of overlapping phenotypes including cerebellar ataxia, spastic paraplegia, and Marinesco-Sjogren-like syndrome. We review previously reported cases of SPG46 and discuss possible genetic differential diagnosis.
Davide Pareyson, , Chiara Pantaleoni, Roberto Eleopra, Giuseppe De Filippis, Isabella Moroni, Elena Freri, Federica Zibordi, Sara Bulgheroni, Emanuela Pagliano,et al.
Springer Science and Business Media LLC
Lombardy was severely hit by the COVID-19 pandemic since February 2020 and the Health System underwent rapid reorganization. Outpatient clinics were stopped for non-urgent patients: it became a priority to manage hundreds of fragile neurological patients who suddenly had less reference points. In Italy, before the pandemic, Televisits were neither recognized nor priced. At the Fondazione IRCCS Istituto Neurologico C. Besta, we reorganized outpatient clinics to deliver Neuro-telemedicine services, including Televisits and Teleneurorehabilitation, since March 2020. A dedicated Working Group prepared the procedure, tested the system, and designed satisfaction questionnaires for adults and children. After a pilot phase, we prepared a procedure for Telemedicine outpatient clinics which was approved by hospital directions. It included prescription, booking, consenting, privacy and data protection, secure connection with patients (Teams Microsoft 365), electronic report preparation and delivery, reporting, and accountability of the services. During the March–September 2020 period, we delivered 3167 Telemedicine services, including 1618 Televisits, to 1694 patients (972 adults, 722 children) with a wide range of chronic neurological disorders. We successfully administered different clinical assessment and scales. Satisfaction among patients and caregivers was very high. During the dramatic emergency, we were able to take care of more than 1600 patients by organizing Neuro-telehealth in a few weeks, lessening the impact of the pandemic on fragile patients with chronic neurological disorders; this strategy is now stably embedded in our care pathways. In Italy, Telehealth is at present recognized and priced and is becoming a stable pillar of the health system.
Kathrin Reetz, Imis Dogan, Ralf-Dieter Hilgers, Paola Giunti, Michael H Parkinson, Caterina Mariotti, Lorenzo Nanetti, Alexandra Durr, Claire Ewenczyk, Sylvia Boesch,et al.
Elsevier BV
BACKGROUND
The European Friedreich's Ataxia Consortium for Translational Studies (EFACTS) investigates the natural history of Friedreich's ataxia. We aimed to assess progression characteristics and to identify patient groups with differential progression rates based on longitudinal 4-year data to inform upcoming clinical trials in Friedreich's ataxia.
METHODS
EFACTS is a prospective, observational cohort study based on an ongoing and open-ended registry. Patients with genetically confirmed Friedreich's ataxia were seen annually at 11 clinical centres in seven European countries (Austria, Belgium, France, Germany, Italy, Spain, and the UK). Data from baseline to 4-year follow-up were included in the current analysis. Our primary endpoints were the Scale for the Assessment and Rating of Ataxia (SARA) and the activities of daily living (ADL). Linear mixed-effect models were used to analyse annual disease progression for the entire cohort and subgroups defined by age of onset and ambulatory abilities. Power calculations were done for potential trial designs. This study is registered with ClinicalTrials.gov, NCT02069509.
FINDINGS
Between Sept 15, 2010, and Nov 20, 2018, of 914 individuals assessed for eligibility, 602 patients were included. Of these, 552 (92%) patients contributed data with at least one follow-up visit. Annual progression rate for SARA was 0·82 points (SE 0·05) in the overall cohort, and higher in patients who were ambulatory (1·12 [0·07]) than non-ambulatory (0·50 [0·07]). ADL worsened by 0·93 (SE 0·05) points per year in the entire cohort, with similar progression rates in patients who were ambulatory (0·94 [0·07]) and non-ambulatory (0·91 [0·08]). Although both SARA and ADL showed slightly greater worsening in patients with typical onset (symptom onset at ≤24 years) than those with late onset (symptom onset ≥25 years), differences in progression slopes were not significant. For a 2-year parallel-group trial, 230 (115 per group) patients would be required to detect a 50% reduction in SARA progression at 80% power: 118 (59 per group) if only individuals who are ambulatory are included. With ADL as the primary outcome, 190 (95 per group) patients with Friedreich's ataxia would be needed, and fewer patients would be required if only individuals with early-onset are included.
INTERPRETATION
Our findings for stage-dependent progression rates have important implications for clinicians and researchers, as they provide reliable outcome measures to monitor disease progression, and enable tailored sample size calculation to guide upcoming clinical trial designs in Friedreich's ataxia.
FUNDING
European Commission, Voyager Therapeutics, and EuroAtaxia.
Stefania Magri, Lorenzo Nanetti, Alessia Mongelli, Elena Rizzo, Franco Taroni, Caterina Mariotti, and Cinzia Gellera
Wiley
Huntington disease (HD) is an autosomal dominant disease characterized by motor, behavioral, and cognitive symptoms, caused by the pathological expansion of more than 35 CAG/CAA repeats in the HTT gene. We describe the phenotype of a patient compatible with HD. Several family members were reported as affected, and a paternal cousin and his daughter carried 39 and 42 CAG/CAA. HD genetic testing in proband showed homozygosity for a 14 CAG/CAA allele. Considering the phenotype and family history, HTT gene sequence was performed, revealing heterozygosity for the c.51C>G variant that changes the last nucleotide before the CAG tract, causing misannealing of forward primer (HD344) and dropout of the expanded allele. Polymerase chain reaction (PCR) analysis performed with an alternative forward primer demonstrated a 41 CAG/CAA allele. The c.51C>G variant was not detected in the affected cousin, thus suggesting a de novo occurrence. The lack of biological samples from the proband father and grandmother prevented further investigations to establish in which family member the variant occurred. These data indicate that patients presenting HD phenotype, and homozygous for a normal HTT CAG/CAA allele should be thoroughly evaluated for the presence of a genetic variant, even de novo, within the repeat region that may hamper genetic diagnosis.
Anna Nigri, Lidia Sarro, Alessia Mongelli, Chiara Pinardi, Luca Porcu, Anna Castaldo, Stefania Ferraro, Marina Grisoli, Maria Grazia Bruzzone, Cinzia Gellera,et al.
Frontiers Media SA
Spinocerebellar ataxias type 2 (SCA2) is an autosomal dominant inherited disease caused by expanded trinucleotide repeats (≥32 CAG) within the coding region of ATXN2 gene. Age of disease onset primarily depends on the length of the expanded region. The majority of subjects carrying the mutation remain free of clinical signs for few decades (“pre-symptomatic” stage), but in proximity of disease onset subtle neurophysiological, cognitive, and structural brain imaging changes may occur. Aims of the present study are to determine the time-window in which early clinical and neurodegenerative MRI changes may be identified, and to evaluate the rate of the disease progression in both preclinical and early disease phases. We performed a 1-year longitudinal study in 42 subjects: 14 SCA2 patients (mean age 39 years, disease duration 7 years, SARA score 9 points), 13 presymptomatic SCA2 subjects (preSCA2, mean age 39 years, expected time to disease onset 16 years), and 15 gene-negative healthy controls (mean age 33 years). All participants underwent genetic test, neurological examination, cognitive tests, and brain MRI. Evaluations were repeated at 1-year interval. Baseline MRI evaluations in SCA2 patients showed significant atrophy in cerebellum, brainstem, basal ganglia and cortex compared to controls, while preSCA2 subjects had isolated volume loss in the pons, and cortical thinning in specific frontal and parietal areas, namely rostral-middle-frontal and precuneus. One-year longitudinal follow-up demonstrated, in SCA2 patients, volume reduction in cerebellum, pons, superior cerebellar peduncles, and midbrain, and only in the cerebellum in preSCA2 subjects. No progression in clinical or cognitive measures was observed in preSCA2 subjects. The rate of volume loss in the cerebellum and subcortical regions greatly differed between patients and preSCA2. In conclusion, our pilot study demonstrated that MRI measures are highly sensitive to identify longitudinal structural changes in SCA2 patients, and in preSCA2 up to a decade before expected disease onset. These findings may contribute in the understanding of early neurodegenerative processes and may be useful in future therapeutical trials.