CAG repeat mosaicism is gene specific in spinocerebellar ataxias.

Expanded CAG repeats in coding regions of different genes are the most common cause of dominantly inherited spinocerebellar ataxias (SCAs). These repeats are unstable through the germline, and larger repeats lead to earlier onset. We measured somatic expansion in blood samples collected from 30 SCA1, 50 SCA2, 74 SCA3, and 30 SCA7 individuals over a mean interval of 8.5 years, along with postmortem tissues and fetal tissues from SCA1, SCA3, and SCA7 individuals to examine somatic expansion at different stages of life. We showed that somatic mosaicism in the blood increases over time. Expansion levels are significantly different among SCAs and correlate with CAG repeat lengths. The level of expansion is greater in individuals with SCA7 who manifest disease compared to that of those who do not yet display symptoms. Brain tissues from SCA individuals have larger expansions compared to the blood. The cerebellum has the lowest mosaicism among the studied brain regions, along with a high expression of ATXNs and DNA repair genes. This was the opposite in cortices, with the highest mosaicism and lower expression of ATXNs and DNA repair genes. Fetal cortices did not show repeat instability. This study shows that CAG repeats are increasingly unstable during life in the blood and the brain of SCA individuals, with gene- and tissue-specific patterns.

Extreme phenotypic heterogeneity in non-expansion spinocerebellar ataxias.

Although the best-known spinocerebellar ataxias (SCAs) are triplet repeat diseases, many SCAs are not caused by repeat expansions. The rarity of individual non-expansion SCAs, however, has made it difficult to discern genotype-phenotype correlations. We therefore screened individuals who had been found to bear variants in a non-expansion SCA-associated gene through genetic testing, and after we eliminated genetic groups that had fewer than 30 subjects, there were 756 subjects bearing single-nucleotide variants or deletions in one of seven genes: CACNA1A (239 subjects), PRKCG (175), AFG3L2 (101), ITPR1 (91), STUB1 (77), SPTBN2 (39), or KCNC3 (34). We compared age at onset, disease features, and progression by gene and variant. There were no features that reliably distinguished one of these SCAs from another, and several genes-CACNA1A, ITPR1, SPTBN2, and KCNC3-were associated with both adult-onset and infantile-onset forms of disease, which also differed in presentation. Nevertheless, progression was overall very slow, and STUB1-associated disease was the fastest. Several variants in CACNA1A showed particularly wide ranges in age at onset: one variant produced anything from infantile developmental delay to ataxia onset at 64 years of age within the same family. For CACNA1A, ITPR1, and SPTBN2, the type of variant and charge change on the protein greatly affected the phenotype, defying pathogenicity prediction algorithms. Even with next-generation sequencing, accurate diagnosis requires dialogue between the clinician and the geneticist.

Reproductive choices and intrafamilial communication in neurogenetic diseases with different self-estimated severities.

BACKGROUND: Low uptake of presymptomatic testing and medically assisted reproduction in families impacted by neurogenetic diseases prompted us to investigate how reproductive options are considered and whether there is a relationship with perceived severity of the disease. We hypothesised that self-estimated severity would influence opinion on reproductive options and that prenatal/preimplantation diagnosis would be a motivation to inform relatives about their risk. METHODS: We invited people impacted by neurogenetic diseases to evaluate the severity of their familial disease using analogic visual scales and to answer questionnaires about reproductive choices and intrafamilial communication. We compared answers between diseases and with the perceived severity of each disease. RESULTS: We analysed 562 questionnaires. Participants were impacted by Huntington disease (n=307), spinocerebellar ataxias (n=114), Steinert myotonic dystrophy (n=82) and amyotrophic lateral sclerosis/frontotemporal dementia (n=59). Self-estimated severity differed between pathologies (p<0.0001). Overall, participants considered prenatal diagnosis (78.0±34.4 out of 100) and preimplantation diagnosis (75.2±36.1 out of 100) justified more than termination of pregnancy (68.6±38.5 out of 100). They were less in favour of gamete donation (48.3±39.8 out of 100) or pregnancy abstention (43.3±40.3 out of 100). The greater the perceived severity of the disease, the more reproductive options were considered justified, except for gamete donation. Prenatal/preimplantation diagnosis was a motivation to inform relatives for only 55.3% of participants (p=0.01). CONCLUSION: Self-estimated severity minimally impacts opinions towards reproductive options. Medically assisted reproduction procedures are rarely sought and do not motivate familial communication.

Fast and reliable detection of repeat expansions in spinocerebellar ataxia using exomes.

Usually, molecular diagnosis of spinocerebellar ataxia is based on a step-by-step approach with targeted sizing of four repeat expansions accounting for most dominant cases, then targeted sequencing of other genes. Nowadays, genome sequencing allows detection of most pathogenic variants in a single step. The ExpansionHunter tool can detect expansions in short-read genome sequencing data. Recent studies have shown that ExpansionHunter can also be used to identify repeat expansions in exome sequencing data. We tested ExpansionHunter on spinocerebellar ataxia exomes in a research context as a second-line analysis, after exclusion of main CAG repeat expansions in half of the probands. First, we confirmed the detection of expansions in seven known expansion carriers and then, after targeted analysis of ATXN1, 2, 3 and 7, CACNA1A, TBP, ATN1, NOP56, AR and HTT in 498 exomes, we found 22 additional pathogenic expansions. Comparison with capillary migration sizing in 247 individuals and confirmation of all expanded alleles detected by ExpansionHunter demonstrated that for these loci, sensitivity and specificity reached 100%. ExpansionHunter detected but underestimated the repeat size for larger expansions, and the normal alleles distribution at each locus should be taken into account to detect expansions. Exome combined with ExpansionHunter is reliable to detect repeat expansions in selected loci as first-line analysis in spinocerebellar ataxia.

Intermediate repeat expansions of TBP and STUB1: Genetic modifier or pure digenic inheritance in spinocerebellar ataxias?

PURPOSE: CAG/CAA repeat expansions in TBP>49 are responsible for spinocerebellar ataxia (SCA) type 17 (SCA17). We previously detected cosegregation of STUB1 variants causing SCA48 with intermediate alleles of TBP in 2 families. This cosegregation questions the existence of SCA48 as a monogenic disease. METHODS: We systematically sequenced TBP repeats in 34 probands of dominant ataxia families with STUB1 variants. In addition, we searched for pathogenic STUB1 variants in probands with expanded alleles of TBP>49 (n = 2) or intermediate alleles of TBP≥40 (n = 47). RESULTS: STUB1 variants were found in half of the TBP40-49 cohort. Mirroring this finding, TBP40-49 alleles were detected in 40% of STUB1 probands. The longer the TBP repeat length, the more likely the occurrence of cognitive impairment (P = .0129) and the faster the disease progression until death (P = .0003). Importantly, 13 STUB1 probands presenting with the full SCA48 clinical phenotype had normal TBP37-39 alleles, excluding digenic inheritance as the sole mode. CONCLUSION: We show that intermediate TBP40-49 alleles act as disease modifiers of SCA48 rather than a STUB1/TBP digenic model. This distinction from what has been proposed before has crucial consequences for genetic counseling in SCA48.

Huntington's Disease with Small CAG Repeat Expansions.

BACKGROUND: Carriers of small cytosine-adenine-guanine (CAG) repeats below 39 in the HTT gene are traditionally associated with milder Huntington's disease, but their clinical profile has not been extensively studied. OBJECTIVE: To study the phenotype of CAG36-38 repeat carriers. METHODS: We included 35 patients and premanifest carriers of CAG36-38 repeats. We compared clinical and neuropsychological profiles of 11 CAG36-38 patients with 11 matched CAG40-42 patients. In addition, we analyzed 243 CAG36-38 individuals from the ENROLL study to complete the phenotype description. RESULTS: Global cognitive efficiency and performance in different cognitive subdomains were similar in small CAG36-38 and typically CAG40-42 expanded individuals. Chorea as the first symptom was significantly less frequent for CAG36-38 patients (P = 0.04) despite similar total motor scores at first visit. Total motor score at last visit was significantly lower in CAG36-38 carriers (P = 0.003). The similar cognitive and different motor profile of CAG36-38 (n = 243) and CAG40-42 (n = 4675) carriers was confirmed in the ENROLL database. Additionally, clinicians were significantly less confident in diagnosing Huntington's disease (P = 2.4e-8) and diagnosis happened significantly later in CAG36-38 (P = 2.2e-6) despite a similar age at symptom onset (P = 0.29). CONCLUSIONS: We showed that small CAG36-38 expansion carriers had a similar cognitive profile to those with the more common CAG40-42 expansions. These individuals may evade molecular diagnosis because of the absence of chorea rather than because of a low penetrance of symptoms. This finding should encourage neurologists to consider Huntington's disease in cognitively impaired elderly patients without typical chorea and anticipate consequences for genetic counseling in their offspring. © 2023 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Clinico-Genetic, Imaging and Molecular Delineation of COQ8A-Ataxia: A Multicenter Study of 59 Patients.

OBJECTIVE: To foster trial-readiness of coenzyme Q8A (COQ8A)-ataxia, we map the clinicogenetic, molecular, and neuroimaging spectrum of COQ8A-ataxia in a large worldwide cohort, and provide first progression data, including treatment response to coenzyme Q10 (CoQ10). METHODS: Cross-modal analysis of a multicenter cohort of 59 COQ8A patients, including genotype-phenotype correlations, 3D-protein modeling, in vitro mutation analyses, magnetic resonance imaging (MRI) markers, disease progression, and CoQ10 response data. RESULTS: Fifty-nine patients (39 novel) with 44 pathogenic COQ8A variants (18 novel) were identified. Missense variants demonstrated a pleiotropic range of detrimental effects upon protein modeling and in vitro analysis of purified variants. COQ8A-ataxia presented as variable multisystemic, early-onset cerebellar ataxia, with complicating features ranging from epilepsy (32%) and cognitive impairment (49%) to exercise intolerance (25%) and hyperkinetic movement disorders (41%), including dystonia and myoclonus as presenting symptoms. Multisystemic involvement was more prevalent in missense than biallelic loss-of-function variants (82-93% vs 53%; p = 0.029). Cerebellar atrophy was universal on MRI (100%), with cerebral atrophy or dentate and pontine T2 hyperintensities observed in 28%. Cross-sectional (n = 34) and longitudinal (n = 7) assessments consistently indicated mild-to-moderate progression of ataxia (SARA: 0.45/year). CoQ10 treatment led to improvement by clinical report in 14 of 30 patients, and by quantitative longitudinal assessments in 8 of 11 patients (SARA: -0.81/year). Explorative sample size calculations indicate that ≥48 patients per arm may suffice to demonstrate efficacy for interventions that reduce progression by 50%. INTERPRETATION: This study provides a deeper understanding of the disease, and paves the way toward large-scale natural history studies and treatment trials in COQ8A-ataxia. ANN NEUROL 2020;88:251-263.

SARA captures disparate progression and responsiveness in spinocerebellar ataxias.

BACKGROUND: The Scale for Assessment and Rating of Ataxia (SARA) is a widely used clinical scale to assess cerebellar ataxia but faces some criticisms about the relevancy of all its items. OBJECTIVES: To prepare for future clinical trials, we analyzed the progression of SARA and its items in several polyQ spinocerebellar ataxias (SCA) from various cohorts. METHODS: We included data from patients with SCA1, SCA2, SCA3, and SCA6 from four cohorts (EUROSCA, RISCA, CRC-SCA, and SPATAX) for a total of 850 carriers and 3431 observations. Longitudinal progression of the SARA and its items was measured. Cohort, stage and genetic effects were tested. We looked at the respective contribution of each item to the total scale. Sensitivity to change of the scale and the impact of item removal was evaluated by calculating sample sizes needed in various scenarios. RESULTS: Longitudinal progression was significantly different between cohorts in SCA1, SCA2 and SCA3, the EUROSCA cohort having the fastest progression. Advanced-stage patients were progressing slower in SCA2 and SCA6. Items were not contributing equally to the full scale through ataxia severity: gait, stance, hand movement, and heel-shin contributed the most in the early stage, and finger-chase, nose-finger, and sitting in later stages. Few items drove the sensitivity to the change of SARA, but changes in the scale structure could not improve its sensitivity in all populations. CONCLUSION: SARA and its item's progression pace showed high heterogeneity across cohorts and SCAs. However, no combinations of items improved the responsiveness in all SCAs or populations taken separately.

Clinical and genetic keys to cerebellar ataxia due to FGF14 GAA expansions.

BACKGROUND: SCA27B caused by FGF14 intronic heterozygous GAA expansions with at least 250 repeats accounts for 10-60% of cases with unresolved cerebellar ataxia. We aimed to assess the size and frequency of FGF14 expanded alleles in individuals with cerebellar ataxia as compared with controls and to characterize genetic and clinical variability. METHODS: We sized this repeat in 1876 individuals from France sampled for research purposes in this cross-sectional study: 845 index cases with cerebellar ataxia and 324 affected relatives, 475 controls, as well as 119 cases with spastic paraplegia, and 113 with familial essential tremor. FINDINGS: A higher frequency of expanded allele carriers in index cases with ataxia was significant only above 300 GAA repeats (10.1%, n = 85) compared with controls (1.1%, n = 5) (p < 0.0001) whereas GAA250-299 alleles were detected in 1.7% of both groups. Eight of 14 index cases with GAA250-299 repeats had other causal pathogenic variants (4/14) and/or discordance of co-segregation (5/14), arguing against GAA causality. We compared the clinical signs in 127 GAA≥300 carriers to cases with non-expanded GAA ataxia resulting in defining a key phenotype triad: onset after 45 years, downbeat nystagmus, episodic ataxic features including diplopia; and a frequent absence of dysarthria. All maternally transmitted alleles above 100 GAA were unstable with a median expansion of +18 repeats per generation (r2 = 0.44; p < 0.0001). In comparison, paternally transmitted alleles above 100 GAA mostly decreased in size (-15 GAA (r2 = 0.63; p < 0.0001)), resulting in the transmission bias observed in SCA27B pedigrees. INTERPRETATION: SCA27B diagnosis must consider both the phenotype and GAA expansion size. In carriers of GAA250-299 repeats, the absence of documented familial transmission and a presentation deviating from the key SCA27B phenotype, should prompt the search for an alternative cause. Affected fathers have a reduced risk of having affected children, which has potential implications for genetic counseling. FUNDING: This work was supported by the Fondation pour la Recherche Médicale, grant number 13338 to JLM, the Association Connaître les Syndrome Cérébelleux - France (to GS) and by the European Union's Horizon 2020 research and innovation program under grant agreement No 779257 ("SOLVE-RD" to GS). DP holds a Fellowship award from the Canadian Institutes of Health Research (CIHR). SK received a grant (01GM1905C) from the Federal Ministry of Education and Research, Germany, through the TreatHSP network. This work was supported by the Australian Government National Health and Medical Research Council grants (GNT2001513 and MRFF2007677) to MB and PJL.

Individual perception of environmental factors that influence lower limbs spasticity in inherited spastic paraparesis.

BACKGROUND: Phenotypic variability is a consistent finding in neurogenetics and therefore applicable to hereditary spastic paraparesis. Identifying reasons for this variability is a challenge. We hypothesized that, in addition to genetic modifiers, extrinsic factors influence variability. OBJECTIVES: Our aim was to describe the clinical variability in hereditary spastic paraparesis from the person's perspective. Our goals were to identify individual and environmental factors that influence muscle tone disorders and derive interventions which could improve spasticity. METHODS: This study was based on self-assessments with questions on nominal and ordinal scales completed by participants with hereditary spastic paraparesis. A questionnaire was completed either in-person in the clinic or electronically via lay organization websites. RESULTS: Among the 325 responders, most had SPG4/SPAST (n = 182, 56%) with a mean age at onset of 31.7 (SD 16.7) years and a mean disease duration of 23 (SD 13.6) years at the time of participation. The 2 factors identified as improving spasticity for > 50% of the responders were physiotherapy (193/325, 59%), and superficial warming (172/308, 55%). Half of the responders (n = 164, 50%) performed physical activity at least once a month and up to once a week. Participants who reported physiotherapy as effective were significantly more satisfied with ≥ 3 sessions per week. Psychologically stressful situations (246/319, 77%) and cold temperatures (202/319, 63%) exacerbated spasticity for most participants. CONCLUSION: Participants perceived that physiotherapy reduced spasticity and that the impact of physiotherapy on spasticity was much greater than other medical interventions. Therefore, people should be encouraged to practice physical activity at least 3 times per week. This study reported participants' opinions: in hereditary spastic paraparesis only functional treatments exist, therefore the participant's expertise is of particular importance.

End-of-Life Discussions With Patients and Caregivers Affected By Neurogenetic Diseases.

Background and Objectives: No effective cure is available for neurogenetic diseases such as Huntington disease, spinocerebellar ataxias, and Friedreich ataxia, all of which cause progressive motor, cognitive, and psychiatric symptoms leading, in the long term, to severe communication (among other) impairments. In end-of-life situations, advanced directives (indications formulated by the patient about end-of-life choices) are one decision-making resource for relatives, caregivers, and health care professionals. Given the slowly progressive nature of these diseases, the related disabilities, and their hereditary component, patients, caregivers, and neurologists are often at a loss concerning the right course of action to take. Our study's aim was to explore patients' and caregivers' perceptions, needs, and expectations around anticipated end-of-life discussions and advanced directives. Methods: DIRAGENE is an observational, cross-sectional, mixed-methods study with a patient-centered component and a primary caregiver-centered component. Observations include disease severity, psychosocial, and emotional scales; in-house questionnaires; and semidirected interviews. Results: We included 124 participants, of which 81 were patients and 43 primary caregivers. Only 16% of the participants knew specifically about advanced directives and 7% had written documents vs 30% and 18% in the general French population, respectively, adjusted for age. Qualitative analysis of the interviews with 15 couples showed notable dissimilarities in ideas about advanced directives between patients and caregivers and that the underlying pathology, severity, and inheritability are less relevant factors regarding end-of-life discussions than age, environment, prior experiences with death, and history of family illness. Most patients (95%) and caregivers (98%) found that participating in the study was helpful in bringing awareness to end-of-life issues, wished to prioritize discussing them with loved ones, and requested assistance in managing them throughout the course of the disease. Discussion: Being affected by severe neurogenetic diseases does not seem to prompt individuals to give much thought to end-of-life planning. However, patients and caregivers welcome comprehensive information and expect progressive support from trained health care professionals in having such discussions. Routine integration of these conversations into medical management through a holistic and adapted approach will benefit patients with illnesses with unfavorable long-term prognoses.

Silver-fluoropolymer (Ag-CFX) films: Kinetic study of silver release, and spectroscopic-microscopic insight into the inhibition of P. fluorescens biofilm formation.

Silver-fluoropolymer (Ag-CFX) composed of encapsulated bioactive nanophases within a thin polymer coating are promising antimicrobial films with excellent bioactivity. In this contribution, we report on Ag-CFX thin films obtained by ion beam co-sputtering, accurately tuning film thickness, and inorganic loading. The Ag-CFX films were characterized by spectroscopic and scanning probe microscopy techniques with respect to composition and swelling behavior. Next to electrothermal atomic absorption spectroscopy (ETAAS) studies, scanning electrochemical microscopy (SECM) experiments in combination with anodic stripping voltammetry (ASV) were carried out to study the release mechanism of silver(I) from the embedded silver nanoparticles (AgNPs). Silver(I) concentration profiles at the Ag-CFX films in contact with water resulted in a release of 1310 ± 50 µg L-1 (n = 3) after 27 h of immersion and corresponded well to the swelling of the films. The antimicrobial properties towards biofilm formation of P. fluorescens were studied by attenuated total reflection Fourier-transform infrared (ATR-FTIR) spectroscopy during a period of 48 h. The obtained IR data revealed biofilm inhibition due to the presence of the antimicrobial layer but also indicated potential surface re-colonization after 30 h of contact with the bacteria-containing solution. The occurrence of cyclic changes in the characteristic IR bands correlated with apparent stress of bottom-layered bacteria, along with re-colonization on top of dead biomass, indicative of potential cannibalism events.

Characterizing cardiac phenotype in Friedreich's ataxia: The CARFA study.

BACKGROUND: Friedreich's ataxia is an autosomal recessive mitochondrial disease caused by a triplet repeat expansion in the frataxin gene (FXN), exhibiting cerebellar sensory ataxia, diabetes and cardiomyopathy. Cardiac complications are the major cause of early death. AIMS: To characterize the cardiac phenotype associated with Friedreich's ataxia, and to assess the evolution of the associated cardiopathy over 1 year. METHODS: This observational single-centre open label study consisted of two groups: 20 subjects with Friedreich's ataxia and 20 healthy controls studied over two visits over 1 year. All subjects had transthoracic echocardiography, cardiac magnetic resonance imaging, cardiopulmonary exercise testing, quantification of serum cardiac biomarkers and neurological assessment. RESULTS: Patients with Friedreich's ataxia had left ventricular hypertrophy, with significantly smaller left ventricular diastolic diameters and volumes and increased wall thicknesses. Cardiac magnetic resonance imaging demonstrated significant concentric left ventricular remodelling, according to the mass/volume ratio, and focal myocardial fibrosis in 50% of patients with Friedreich's ataxia. Cardiopulmonary exercise testing showed alteration of left ventricular diastolic filling in patients with Friedreich's ataxia, with an elevated VE/VCO2 slope (ventilatory flow/exhaled volume of carbon dioxide). High-sensitivity troponin T plasma concentrations were higher in subjects with Friedreich's ataxia. None of the previous variables changed at 1 year. Neurological assessments remained stable for both groups, except for the nine-hole pegboard test, which was altered over 1 year. CONCLUSIONS: The multivariable characterization of the cardiac phenotype of patients with Friedreich's ataxia was significantly different from controls at baseline. Over 1 year there were no clinically significant changes in patients with Friedreich's ataxia compared with healthy controls, whereas the neurological severity score increased modestly.

Safety and efficacy of riluzole in spinocerebellar ataxia type 2 in France (ATRIL): a multicentre, randomised, double-blind, placebo-controlled trial.

BACKGROUND: Riluzole has been reported to be beneficial in patients with cerebellar ataxia; however, effectiveness in individual subtypes of disease is unclear due to heterogeneity in participants' causes and stages of disease. Our aim was to test riluzole in a single genetic disease, spinocerebellar ataxia type 2. METHODS: We did a randomised, double-blind, placebo-controlled, multicentre trial (the ATRIL study) at eight national reference centres for rare diseases in France that were part of the Neurogene National Reference Centre for Rare Diseases. Participants were patients with spinocerebellar ataxia type 2 with an age at disease onset of up to 50 years and a scale for the assessment and rating of ataxia (SARA) score of at least 5 and up to 26. Patients were randomly assigned centrally (1:1) to receive either riluzole 50 mg orally or placebo twice per day for 12 months. Two visits, at baseline and at 12 months, included clinical measures and 3T brain MRI. The primary endpoint was the proportion of patients whose SARA score improved by at least 1 point. Analyses were done in the intention-to-treat population (all participants who were randomly assigned) and were done with only the observed data (complete case analysis). This trial is registered at ClinicalTrials.gov (NCT03347344) and has been completed. FINDINGS: Between Jan 18, 2018, and June 14, 2019, we enrolled 45 patients. 22 patients were randomly assigned to receive riluzole and 23 to receive placebo. Median age was 42 years (IQR 36-57) in the riluzole group and 49 years (40-56) in the placebo group and 23 (51%) participants were women. All participants presented with moderate-stage disease, characterised by a median SARA score of 13·5 (IQR 9·5-16·5). The primary endpoint, SARA score improvement of at least 1 point after 12 months, was observed in seven patients (32%) in the treated group versus nine patients (39%) in the placebo group, with a mean difference of -10·3% (95% CI -37·4% to 19·2%; p=0·75). SARA score showed a median increase (ie, worsening) of 0·5 points (IQR -1·5 to 1·5) in the riluzole group versus 0·3 points (-1·0 to 2·5) in the placebo group (p=0·70). No serious adverse event was reported in the riluzole-treated group whereas four patients in placebo group had a serious adverse event (hepatic enzyme increase, fracture of external malleolus, rectorrhagia, and depression). The number of patients with adverse events was similar in both groups (riluzole 16 [73%] patients vs placebo 19 [83%] patients; p=0·49). INTERPRETATION: We were able to recruit 45 patients moderately affected by spinocerebellar ataxia type 2 for this trial. Riluzole did not improve clinical or radiological outcomes in these patients. However, our findings provide data on progression of spinocerebellar ataxia type 2 that might prove to be valuable for the design of other clinical trials. FUNDING: French Ministry of Health.

Informing about genetic risk in families with Huntington disease: comparison of attitudes across two decades.

The low uptake of presymptomatic testing in Huntington disease prompted us to question family members on how they handle the transmission of information regarding genetic risk. We hypothesised that in 2019, parents would inform their at-risk children about their genetic risk more and at a younger age than in 2000, given the availability of prenatal diagnosis, French legislation changes since 2011, and recent therapeutic advances. We made a questionnaire available about the transmission of genetic information within families with Huntington disease in 2000 and 2019. We obtained 443 questionnaires (295 in 2019 and 148 in 2000). Participants were mainly at-risk for Huntington disease (n = 113), affected (n = 85), and spouses (n = 154). In 2019, participants had a higher mean education level (p < 0.01) and a mean age of 44.1 ± 15.1 years (vs 48.1 ± 11.4 years in 2000, p < 0.01). They had been informed about the risk of being a carrier at around 30 years of age (29.0 ± 14.2 in 2019 vs 32.2 ± 13.8 in 2000, p = 0.09). However, they would inform at an earlier age (≤18 years, 67% vs 59%, p = 0.16). Information on transmission risk had been given primarily by parents (45% vs 30%, p = 0.06). In addition, genetic testing for relatives unaware of their status was recommended more frequently in 2019 (46% vs 32%, p < 0.001). Respondents in 2019 recommended genetic testing more often but overall attitudes towards information and testing have not changed significantly over the 19-year time period since the questionnaire was first delivered even despite recent clinical trials potential disease modifying therapies.

The ARCA Registry: A Collaborative Global Platform for Advancing Trial Readiness in Autosomal Recessive Cerebellar Ataxias.

Autosomal recessive cerebellar ataxias (ARCAs) form an ultrarare yet expanding group of neurodegenerative multisystemic diseases affecting the cerebellum and other neurological or non-neurological systems. With the advent of targeted therapies for ARCAs, disease registries have become a precious source of real-world quantitative and qualitative data complementing knowledge from preclinical studies and clinical trials. Here, we review the ARCA Registry, a global collaborative multicenter platform (>15 countries, >30 sites) with the overarching goal to advance trial readiness in ARCAs. It presents a good clinical practice (GCP)- and general data protection regulation (GDPR)-compliant professional-reported registry for multicenter web-based capture of cross-center standardized longitudinal data. Modular electronic case report forms (eCRFs) with core, extended, and optional datasets allow data capture tailored to the participating site's variable interests and resources. The eCRFs cover all key data elements required by regulatory authorities [European Medicines Agency (EMA)] and the European Rare Disease (ERD) platform. They capture genotype, phenotype, and progression and include demographic data, biomarkers, comorbidity, medication, magnetic resonance imaging (MRI), and longitudinal clinician- or patient-reported ratings of ataxia severity, non-ataxia features, disease stage, activities of daily living, and (mental) health status. Moreover, they are aligned to major autosomal-dominant spinocerebellar ataxia (SCA) and sporadic ataxia (SPORTAX) registries in the field, thus allowing for joint and comparative analyses not only across ARCAs but also with SCAs and sporadic ataxias. The registry is at the core of a systematic multi-component ARCA database cluster with a linked biobank and an evolving study database for digital outcome measures. Currently, the registry contains more than 800 patients with almost 1,500 visits representing all ages and disease stages; 65% of patients with established genetic diagnoses capture all the main ARCA genes, and 35% with unsolved diagnoses are targets for advanced next-generation sequencing. The ARCA Registry serves as the backbone of many major European and transatlantic consortia, such as PREPARE, PROSPAX, and the Ataxia Global Initiative, with additional data input from SPORTAX. It has thus become the largest global trial-readiness registry in the ARCA field.

Hypothermia and neuroprotection by sulfide after cardiac arrest and cardiopulmonary resuscitation.

BACKGROUND: Poor neurological outcome remains a major problem in patients suffering cardiac arrest. Recent data have demonstrated potent neuroprotective effects of the administration of sulfide donor compounds after ischaemia/reperfusion injury following cardiac arrest and resuscitation. Therefore, we sought to evaluate the impact of sodium sulfide (Na(2)S), a liquid hydrogen sulfide donor on core body temperature and neurological outcome after cardiac arrest in rats. METHODS: Fifty male Wistar rats were randomized into two groups (sulfide vs. placebo, n=25 per group). Cardiac arrest was induced by transoesophageal ventricular fibrillation during general anaesthesia. After 6 min of global cerebral ischaemia, animals were resuscitated by external chest compressions combined with defibrillation. An investigator blinded bolus of either Na(2)S (0.5 mg/kg body weight) or placebo 1 min before the beginning of CPR, followed by a continuous infusion of Na(2)S (1 mg/kg body weight/h) or placebo for 6 h, was administered intravenously. 1 day, 3 days, and 7 days after restoration of spontaneous circulation, neurological outcome was evaluated by a tape removal test. After 7 days of reperfusion, coronal brain sections were analyzed by TUNEL- and Nissl-staining. A caspase activity assay was used to determine antiapoptotic properties of Na(2)S. RESULTS: Temperature course was similar in both groups (mean minimal temperature in the sulfide group 31.3±1.2°C vs. 30.8±1.9°C in the placebo group; p=0.29). Despite significant neuroprotection demonstrated by the tape removal test after 3 days of reperfusion in the sulfide treated group, there was no significant difference in neuronal survival at day 7. Likewise results from TUNEL-staining revealed no differences in the amount of apoptotic cell death between the groups after 7 days of reperfusion. CONCLUSION: In our rat model of cardiac arrest, sulfide therapy was associated with only a short term beneficial effect on neurological outcome.