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OBJECTIVES: Friedreich ataxia (FRDA) is a rare genetic disorder caused by mutations in the FXN gene, leading to progressive coordination loss and other symptoms. The recently approved omaveloxolone targets this condition but is limited to patients over 16 years of age, highlighting the need for pediatric treatments due to the disorders early onset and more rapid progression in children. This population also experiences increased non-neurological complications; the FACHILD study aimed to augment and expand the knowledge about the natural history of the disease and clinical outcome assessments for trials in children in FRDA. METHODS: The study enrolled 108 individuals aged 7-18 years with a confirmed FRDA diagnosis, with visits occurring from October 2017 to November 2022 across three institutions. Several measures were introduced to minimize the impact of the COVID-19 pandemic, including virtual visits. Outcome measures centered on the mFARS score and its subscores, and data were analyzed using mixed models for repeated measures. For context and to avoid misinterpretation, the analysis was augmented with data from patients enrolled in the Friedreichs Ataxia Clinical Outcome Measures Study. RESULTS: Results confirmed the general usefulness of the mFARS score in children, but also highlighted issues, particularly with the upper limb subscore (FARS B). Increased variability, limited homogeneity across study subgroups, and potential training effects might limit mFARS application in clinical trials in pediatric populations. INTERPRETATION: The FARS E (Upright Stability) score might be a preferred outcome measure in this patient population.

Characterizing bedside oculomotor deficits is a critical factor in defining the clinical presentation of hereditary ataxias. Quantitative assessments are increasingly available and have significant advantages, including comparability over time, reduced examiner dependency, and sensitivity to subtle changes. To delineate the potential of quantitative oculomotor assessments as digital-motor outcome measures for clinical trials in ataxia, we searched MEDLINE for articles reporting on quantitative eye movement recordings in genetically confirmed or suspected hereditary ataxias, asking which paradigms are most promising for capturing disease progression and treatment response. Eighty-nine manuscripts identified reported on 1541 patients, including spinocerebellar ataxias (SCA2, n = 421), SCA3 (n = 268), SCA6 (n = 117), other SCAs (n = 97), Friedreich ataxia (FRDA, n = 178), Niemann-Pick disease type C (NPC, n = 57), and ataxia-telangiectasia (n = 85) as largest cohorts. Whereas most studies reported discriminatory power of oculomotor assessments in diagnostics, few explored their value for monitoring genotype-specific disease progression (n = 2; SCA2) or treatment response (n = 8; SCA2, FRDA, NPC, ataxia-telangiectasia, episodic-ataxia 4). Oculomotor parameters correlated with disease severity measures including clinical scores (n = 18 studies (SARA: n = 9)), chronological measures (e.g., age, disease duration, time-to-symptom onset; n = 17), genetic stratification (n = 9), and imaging measures of atrophy (n = 5). Recurrent correlations across many ataxias (SCA2/3/17, FRDA, NPC) suggest saccadic eye movements as potentially generic quantitative oculomotor outcome. Recommendation of other paradigms was limited by the scarcity of cross-validating correlations, except saccadic intrusions (FRDA), pursuit eye movements (SCA17), and quantitative head-impulse testing (SCA3/6). This work aids in understanding the current knowledge of quantitative oculomotor parameters in hereditary ataxias, and identifies gaps for validation as potential trial outcome measures in specific ataxia genotypes.

Cerebellar transcranial direct current stimulation (ctDCS) has emerged as a promising, non-invasive, and safe neuromodulatory intervention capable of reducing ataxia symptoms and restoring cerebellum-motor connectivity. However, previous studies have only applied ctDCS in isolation, without association with specific training. This study aimed to assess the effect of ctDCS combined with gait training on functional mobility, balance, and symptoms and severity of ataxia. A randomized, triple-blind, sham-controlled, bi-center clinical trial was conducted with forty-four adults with cerebellar ataxia. Volunteers were randomized to receive five daily sessions of either real ctDCS (n = 11; 2 mA for 25 min) or sham ctDCS (n = 11) during gait training. Functional mobility, balance, and symptoms and severity of ataxia were assessed using the Time Up and Go test, the MiniBESTest, and the Scale for the Assessment and Rating of Ataxia (SARA), respectively, before and after the interventions. Both groups showed improvement in functional mobility, but there was no significant difference between the ctDCS and sham groups. However, the ctDCS group demonstrated significant improvements in cerebellar ataxia severity as reflected by SARA scores, particularly in tests of stance, sitting, speech disturbance, nose-finger test, and heel-shin slide test. Notably, no improvements were observed in balance. This study indicates that while ctDCS combined with gait training may improve specific symptoms of cerebellar ataxia, it does not significantly enhance overall functional mobility compared to sham treatment. [ABSTRACT FROM AUTHOR]

Neuropsychiatric symptoms (NPS) are common in hereditary ataxias as a part of the cerebellar cognitive affective syndrome. In Friedreich ataxia (FRDA), one of the most common hereditary ataxias, depressive symptoms were previously reported, but little is known about other NPS. We aimed to study the presence and severity of a broad range of NPS in individuals with FRDA and assess the relationship between the NPS and the disease severity, cognition, and quality of life and to examine the concordance between the NPS reported by the patients and by their informants. Mild Behavioral Impairment Checklist (MBI-C), a questionnaire designed for screening NPS in the early stages of neurodegenerative diseases, was administered to informants of individuals with FRDA and healthy controls and to people with FRDA themselves. Compared to healthy controls, patients with FRDA scored significantly higher in the total MBI-C score, emotion dysregulation domain (corresponding to depression and anxiety), and decreased motivation domain. When assessed by caregiver, the total MBI-C score and several NPS domains correlated with activities of daily living. Only psychotic symptoms were related to ataxia severity and general cognition. When endorsed by patients, only the relation between few MBI-C domains and quality of life was observed. We found slight to moderate agreement between informant-rated and patient-rated scores. NPS, particularly emotion dysregulation and decreased motivation, are common and clinically relevant in FRDA and should receive more attention due to their potential impact on quality of life and the possibility of therapeutic intervention. [ABSTRACT FROM AUTHOR]

The article discusses the use of Omaveloxolone for treating Friedreich Ataxia, an autosomal recessive disorder caused by mutations in the frataxin gene. Omaveloxolone aims to counteract the pathologies associated with FRDA by enhancing antioxidant defenses and restoring redox balance. While promising outcomes have been observed in neurological function, its impact on cardiovascular outcomes remains unclear, necessitating further research. Clinical trials have shown improvements in neurological symptoms with omaveloxolone treatment, but its effect on cardiac function requires more investigation due to the high prevalence of cardiovascular disease in individuals with FRDA. [Extracted from the article]

Background: Friedreich ataxia (FRDA) is an autosomal recessive neurodegenerative disorder caused by an expanded GAA repeat in the first intron of the FXN gene. Objective: The aim of this study was to analyze leukocyte telomeres length (LTL) in FRDA to verify the possible relationships between LTL and disease progression. We investigated LTL in a cohort of FRDA biallelic patients (n = 61), heterozygous (n = 29), and age‐matched healthy subjects (n = 87). Methods: LTL was measured by real‐time polymerase chain reaction quantitative analysis (qPCR). Results: The results showed that before 35 years of age, leukocyte telomeres were longer in patients than in controls, whereas the reverse applies in patients above 36 years of age. Interestingly, LTL was greater than controls at any age in heterozygous subjects. This picture mirrors what has been previously observed in vitro in FRDA cultured fibroblasts, showing significantly longer telomeres at early passages because of activation of an alternative lengthening of telomeres (ALT)‐like mechanism, but showing accelerated telomere shortening as population doubling increases. GAA1 repeat length is positively correlated with the LTL and negatively correlated with the age at blood sampling. The relationship of LTL with clinical parameters (cardiomyopathy, diabetes, dependence on a wheelchair) was also analyzed. Significantly shorter leukocyte telomeres were associated with the presence of cardiomyopathy, but not with diabetes and the dependence on a wheelchair. Conclusions: Overall, the present study indicates that telomere length analysis in FRDA may be a relevant biomarker for following the stages of the disease. © 2024 The Author(s). Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society. [ABSTRACT FROM AUTHOR]

Vatiquinone, a 15‐lipoxygenase inhibitor, is in development for patients with Friedreich ataxia. The study determined the effect of vatiquinone on electrocardiogram parameters. This was a 2‐part, single‐center, randomized, double‐blinded, and placebo‐controlled study. Part 1 used an adaptive approach to identify a supratherapeutic dose, while Part 2 evaluated the effect of vatiquinone on Fridericia corrected QT interval (QTcF). A safe and tolerated supratherapeutic dose of 1400 mg was identified. Concentration‐QTcF analysis confirmed there was no statistically significant relationship between vatiquinone concentration and QTcF. QTcF effect (ie, ΔΔQTcF) exceeding 10 milliseconds was excluded for concentrations up to approximately 11,500 ng/mL. By‐time‐point analysis confirmed that least‐squares mean ΔΔQTcF was below 10 milliseconds. Largest least‐squares mean ΔΔQTcF of 1.5 milliseconds was observed at 2 hours after dosing. Vatiquinone did not have a clinically relevant effect on heart rate nor on cardiac conduction (PR interval and QRS interval). No new safety signals were found, as safety data are consistent with the known safety profile of vatiquinone. These findings altogether demonstrated that there is a minimal cardiac risk for vatiquinone concentrations up to the supratherapeutic dose level. [ABSTRACT FROM AUTHOR]

Abstract Neuropsychiatric symptoms (NPS) are common in hereditary ataxias as a part of the cerebellar cognitive affective syndrome. In Friedreich ataxia (FRDA), one of the most common hereditary ataxias, depressive symptoms were previously reported, but little is known about other NPS. We aimed to study the presence and severity of a broad range of NPS in individuals with FRDA and assess the relationship between the NPS and the disease severity, cognition, and quality of life and to examine the concordance between the NPS reported by the patients and by their informants. Mild Behavioral Impairment Checklist (MBI-C), a questionnaire designed for screening NPS in the early stages of neurodegenerative diseases, was administered to informants of individuals with FRDA and healthy controls and to people with FRDA themselves. Compared to healthy controls, patients with FRDA scored significantly higher in the total MBI-C score, emotion dysregulation domain (corresponding to depression and anxiety), and decreased motivation domain. When assessed by caregiver, the total MBI-C score and several NPS domains correlated with activities of daily living. Only psychotic symptoms were related to ataxia severity and general cognition. When endorsed by patients, only the relation between few MBI-C domains and quality of life was observed. We found slight to moderate agreement between informant-rated and patient-rated scores. NPS, particularly emotion dysregulation and decreased motivation, are common and clinically relevant in FRDA and should receive more attention due to their potential impact on quality of life and the possibility of therapeutic intervention.

Friedreich's ataxia (FA) is an autosomal recessive disorder caused by reduced frataxin (FXN) expression in mitochondria, where the lethal component is cardiomyopathy. Using the conditional Fxnflox/null::MCK-Cre knock-out (Fxn-cKO) mouse model, we discovered significant sex differences in the progression towards heart failure, with Fxn-cKO males exhibiting a worse cardiac phenotype, low survival rate, kidney and reproductive organ deficiencies. These differences are likely due to a decline in testosterone in Fxn-cKO males. The decrease in testosterone was related to decreased expression of proteins involved in cholesterol transfer into the mitochondria: StAR and TSPO on the outer mitochondrial membrane, and the cholesterol side-chain cleavage enzyme P450scc and ferredoxin on the inner mitochondrial membrane. Expression of excitation-contraction coupling proteins (L-type calcium channel, RyR2, SERCA2, phospholamban and CaMKIIδ) was decreased significantly more in Fxn-cKO males. This is the first study that extensively investigates the sexual dimorphism in FA mouse model with cardiac calcium signaling impairment.

OBJECTIVE: The natural history of Friedreich ataxia is being investigated in a multi-center longitudinal study designated the Friedreich ataxia Clinical Outcome Measures Study (FACOMS). To understand the utility of this study in analysis of clinical trials, we performed a propensity-matched comparison of data from the open-label MOXIe extension (omaveloxolone) to that from FACOMS. METHODS: MOXIe extension patients were matched to FACOMS patients using logistic regression to estimate propensity scores based on multiple covariates: sex, baseline age, age of onset, baseline modified Friedreich Ataxia Rating scale (mFARS) score, and baseline gait score. The change from baseline in mFARS at Year 3 for the MOXIe extension patients compared to the matched FACOMS patients was analyzed as the primary efficacy endpoint using mixed model repeated measures analysis. RESULTS: Data from the MOXIe extension show that omaveloxolone provided persistent benefit over 3 years when compared to an untreated, matched cohort from FACOMS. At each year, in all analysis populations, patients in the MOXIe extension experienced a smaller change from baseline in mFARS score than matched FACOMS patients. In the primary pooled population (136 patients in each group) by Year 3, patients in the FACOMS matched set progressed 6.6 points whereas patients treated with omaveloxolone in MOXIe extension progressed 3 points (difference = -3.6; nominal p value = 0.0001). INTERPRETATION: These results suggest a meaningful slowing of Friedreich ataxia progression with omaveloxolone, and consequently detail how propensity-matched analysis may contribute to understanding of effects of therapeutic agents. This demonstrates the direct value of natural history studies in clinical trial evaluations.

Friedreich’s Ataxia (FRDA) is the most common autosomal recessive ataxia worldwide and is caused by biallelic unstable intronic GAA expansions at FXN. With its limited therapy and the recent approval of the first disease-modifying agent for FRDA, the search for biological markers is urgently needed to assist and ease the development of therapies. MiRNAs have emerged as promising biomarkers in various medical fields such as oncology, cardiology, epilepsy and neurology as well. Cell-free plasmatic miRNAs have potential advantages as biomarkers because of their size, stability against blood RNases, relative ease of obtaining, storage and measurement. In this study, we attempted to characterize the plasma miRNA signature (RNA-Seq followed by qRT-PCR) and its clinical/structural correlates in a cohort of Brazilian patients with FRDA. Our results showed that miR-26a-5p is upregulated and miR-15a-5p is downregulated. The first was correlated with age at onset, cerebellum volume, spinal cord cross-sectional area (C2-CSA) and the left ventricle mass (LV_Mass). For the miR-15a-5p, significant correlations were found with cerebellum volume, spinal cord eccentricity and LV_Mass. It has been previously hypothesized that these miRs target BDNF, modulating its expression and, when this gene is downregulated, it leads to neuronal loss, explaining the ataxic phenotype and our results reinforce this hypothesis. The miR-26a-5p was already associated with cardiomyocyte hypertrophy through the increased NLRP3 inflammasome activity, which is indirectly linked with cardiac hypertrophy. Considering that, we propose these miRNAs as possible prognostic biomarkers for FRDA. However, longitudinal studies are still needed to validate their clinical use. [ABSTRACT FROM AUTHOR]

Cerebellar pathology engenders the disturbance of movement that characterizes Friedreich ataxia (FRDA), yet the impact of cerebellar pathology on cognition in FRDA remains unclear. Numerous studies have unequivocally demonstrated the role of the cerebellar pathology in disturbed cognitive, language and affective regulation, referred to as Cerebellar Cognitive Affective Syndrome (CCAS), and quantified by the CCAS-Scale (CCAS-S). The presence of dysarthria in many individuals with ataxia, particularly FRDA, may confound results on some items of the CCAS-S resulting in false-positive scores. This study explored the relationship between performance on the CCAS-S and clinical metrics of disease severity in 57 adults with FRDA. In addition, this study explored the relationship between measures of intelligibility and naturalness of speech and scores on the CCAS-S in a subgroup of 39 individuals with FRDA. We demonstrated a significant relationship between clinical metrics and performance on the CCAS-S. In addition, we confirmed the items that returned the greatest rate of failure were based on Verbal Fluency Tasks, revealing a significant relationship between these items and measures of speech. Measures of speech explained over half of the variance in the CCAS-S score suggesting the role of dysarthria in the performance on the CCAS-S is not clear. Further work is required prior to adopting the CCAS-S as a cognitive screening tool for individuals with FRDA. [ABSTRACT FROM AUTHOR]

Friedreich's Ataxia (FRDA) is the leading cause of ataxia worldwide, but data on epidemiology and diagnostic journey are scarce, particularly in Latin America. Herein we estimated the prevalence of FRDA in the most populous Brazilian state and characterized the diagnostic odyssey of the disease. We received anonymized data of patients with FRDA from advocacy groups and physicians. Prevalence was estimated dividing the number of patients by the population of the state as reported in the last census. Patients were invited to answer an online survey to describe clinical data and diagnostic journey of the disease. FRDA estimated prevalence was 0.367:100,000, with a slight predominance of women (58.2% vs 41.7%). One hundred and four patients answered the survey (mean age of 37.3 ± 13.8 years; 75.9% classical and 24.0% late onset). On average, 6.2 ± 4.1 physicians were visited before reaching the diagnosis. Mean diagnostic delay was 7.8 ± 6.7 years; no difference between classical and LOFA groups was found. Most of the patients reported unsteadiness and gait abnormalities as the first symptom. Neurologists and orthopedical surgeons were the main specialties first sought by patients. We found a prevalence of 0.36:100,000 for FRDA in the state of São Paulo, Brazil. The disease is characterized by remarkable diagnostic delay, with no relevant differences between classical and LOFA patients. [ABSTRACT FROM AUTHOR]

Omaveloxolone (SKYCLARYS®) is approved for the treatment of Friedreich ataxia (FA) in patients aged ≥16 years in the United States and European Union (EU). The recommended dosage is 150 mg administered orally once daily as three 50‐mg capsules. However, some patients with FA may have oropharyngeal dysphagia or difficulty swallowing whole capsules; therefore, alternate method(s) of administration are needed. A Phase 1 clinical study in 32 healthy volunteers evaluated the relative bioavailability, safety, and tolerability of a single dose of omaveloxolone when capsule contents were sprinkled on and mixed in applesauce compared to when taken as intact capsules. Palatability when sprinkled on and mixed in applesauce was assessed with a questionnaire. After a single 150‐mg dose, the peak and overall exposures of omaveloxolone were similar irrespective of administration method, with the 90% CIs of the geometric least squares mean ratio (%) for maximum plasma concentration (Cmax), AUC0‐t, and AUC0‐∞ within the 80% to 125% reference intervals. Omaveloxolone was absorbed more slowly as intact capsules (median tmax, 10 h) compared with sprinkled capsule contents over applesauce (median tmax, 6 h). With chronic daily administration of omaveloxolone to treat FA, the 4‐h difference in tmax is not considered clinically relevant. Sprinkled omaveloxolone capsule contents on applesauce were well tolerated, with acceptable palatability and no serious adverse events. Given the similar systemic exposure when capsules were swallowed whole, sprinkling omaveloxolone capsule contents on and mixing in applesauce is a feasible alternative method of administering omaveloxolone and has been included in both the United States and EU prescribing information. [ABSTRACT FROM AUTHOR]

Friedreich Ataxia (FRDA) is an inherited neuromuscular disorder triggered by a deficit of the mitochondrial protein frataxin. At a cellular level, frataxin deficiency results in insufficient iron–sulfur cluster biosynthesis and impaired mitochondrial function and adenosine triphosphate production. The main clinical manifestation is a progressive balance and coordination disorder which depends on the involvement of peripheral and central sensory pathways as well as of the cerebellum. Besides the neurological involvement, FRDA affects also the striated muscles. The most prominent manifestation is a hypertrophic cardiomyopathy, which also represents the major determinant of premature mortality. Moreover, FRDA displays skeletal muscle involvement, which contributes to the weakness and marked fatigue evident throughout the course of the disease. Herein, we review skeletal muscle findings in FRDA generated by functional imaging, histology, as well as multiomics techniques in both disease models and in patients. Altogether, these findings corroborate a disease phenotype in skeletal muscle and support the notion of progressive mitochondrial damage as a driver of disease progression in FRDA. Furthermore, we highlight the relevance of skeletal muscle investigations in the development of biomarkers for early-phase trials and future therapeutic strategies in FRDA. [ABSTRACT FROM AUTHOR]

The translocator protein TSPO is an evolutionary conserved mitochondrial protein overexpressed in various contexts of neurodegeneration. Friedreich Ataxia (FA) is a neurodegenerative disease due to GAA expansions in the FXN gene leading to decreased expression of frataxin, a mitochondrial protein involved in the biosynthesis of iron-sulfur clusters. We previously reported that Tspo was overexpressed in a Drosophila model of this disease generated by CRISPR/Cas9 insertion of approximately 200 GAA in the intron of fh , the fly frataxin gene. Here, we describe a new Drosophila model of FA with 42 GAA repeats, called fh-GAAs. The smaller expansion size allowed to obtain adults exhibiting hallmarks of the FA disease, including short lifespan, locomotory defects and hypersensitivity to oxidative stress. The reduced lifespan was fully rescued by ubiquitous expression of human FXN , confirming that both frataxins share conserved functions. We observed that Tspo was overexpressed in heads and decreased in intestines of these fh-GAAs flies. Then, we further overexpressed Tspo specifically in glial cells and observed improved survival. Finally, we investigated the effects of Tspo overexpression in healthy flies. Increased longevity was conferred by glial-specific overexpression, with opposite effects in neurons. Overall, this study highlights protective effects of glial TSPO in Drosophila both in a neurodegenerative and a healthy context. • A 42 GAA-based Drosophila model of Friedreich Ataxia exhibit hallmarks of the disease. • Overexpression of Tspo in glial cells improves survival of frataxin-deficient flies. • Glial but not neuron-specific overexpression of Tspo increases Drosophila lifespan. [ABSTRACT FROM AUTHOR]

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The last decade has witnessed major breakthroughs in identifying novel genetic causes of hereditary ataxias, deepening our understanding of disease mechanisms, and developing therapies for these debilitating disorders. This article reviews the currently approved and most promising candidate pharmacotherapies in relation to the known disease mechanisms of the most prevalent autosomal recessive ataxias. Omaveloxolone is an Nrf2 activator that increases antioxidant defense and was recently approved for treatment of Friedreich ataxia. Its therapeutic effect is modest, and further research is needed to find synergistic treatments that would halt or reverse disease progression. Promising approaches include upregulation of frataxin expression by epigenetic mechanisms, direct protein replacement, and gene replacement therapy. For ataxia-telangiectasia, promising approaches include splice-switching antisense oligonucleotides and small molecules targeting oxidative stress, inflammation, and mitochondrial function. Rare recessive ataxias for which disease-modifying therapies exist are also reviewed, emphasizing recently approved therapies. Evidence supporting the use of riluzole and acetyl-leucine in recessive ataxias is discussed. Advances in genetic therapies for other neurogenetic conditions have paved the way to implement feasible approaches with potential dramatic benefits. Particularly, as we develop effective treatments for these conditions, we may need to combine therapies, consider newborn testing for pre-symptomatic treatment, and optimize non-pharmacological approaches. [ABSTRACT FROM AUTHOR]

Background: A drug repositioning effort supported the possible use of the anti-HIV drug etravirine as a disease-modifying drug for Friedreich ataxia (FRDA). Etravirine increases frataxin protein and corrects the biochemical defects in cells derived from FRDA patients. Because of these findings, and since etravirine displays a favorable safety profile, we conducted a pilot open-label phase 2 clinical trial assessing the safety and potential efficacy of etravirine in FRDA patients. Methods: Thirty-five patients were stratified into three severity groups and randomized to etravirine 200 mg/day or 400 mg/day. They were treated for 4 months. Safety endpoints were the number and type of adverse events and number of dropouts. Efficacy endpoints were represented by changes in peak oxygen uptake and workload as measured by incremental exercise test, SARA score, cardiac measures, measures of QoL and disability. Data were collected 4 months before the start of the treatment (T − 4), at the start (T0), at the end (T4) and 4 months after the termination of the treatment (T + 4). Results: Etravirine was reasonably tolerated, and adverse events were generally mild. Four months of etravirine treatment did not significantly increase the peak oxygen uptake but was associated with a change in the progression of the SARA score (p value < 0.001), compared to the 4 months pre- and post-treatment. It also significantly increased peak workload (p value = 0.021). No changes in the cardiac measures were observed. Health and QoL measures showed a worsening at the suspension of the drug. Conclusions: In this open trial etravirine treatment was safe, reasonably well tolerated and appreciably improved neurological function and exercise performance. Even though a placebo effect cannot be ruled out, these results suggest that etravirine may represent a potential therapeutic agent in FRDA deserving testing in a randomized placebo-controlled clinical trial. [ABSTRACT FROM AUTHOR]

Purpose: Friedreich ataxia (FDRA) is a debilitating neurodegenerative disease that can have ophthalmological manifestations including visual dysfunction, nystagmus, and optic atrophy. However, severe photophobia has not been reported nor evaluated with functional magnetic resonance imaging (fMRI). Methods: A 64-year-old white female with a 37-year history of FDRA presented to the eye clinic with worsening photophobia of 3 years. To measure her visual cortex activation and subjective responses during episodes of photophobia, she underwent event-related fMRI with light stimuli. In comparison, the same protocol was conducted in an individual with photophobia but without FDRA. After the fMRI, both patients were treated with 35 units of BoNT-A applied to the forehead. Results: Analysis of visual cortex activity in response to light stimulus in the FDRA patient showed no correlation between blood oxygen level dependent (BOLD) activation and light stimuli in the first (r = −0.100, p = 0.235), and a weak negative correlation in the second half of the fMRI scan (r = −0.236 p = 0.004). In notable contrast, significant positive correlations were noted between visual cortex activity and the light stimulus (1st half: r = 0.742, p

ABSTRACT This case report presents the management of tachycardiomyopathy (TCM) in a patient with Friedreich ataxia, a hereditary disorder characterized by progressive neurodegeneration and associated cardiac complications. The patient exhibited severe tachycardia‐induced cardiac dysfunction, complicating the clinical picture due to the overlapping neurological symptoms of Friedreich ataxia. Utilizing a 3D mapping system, catheter ablation was performed to accurately identify and target the arrhythmogenic foci contributing to the patient's TCM. The procedure resulted in significant symptom relief and improvement in cardiac function, underscoring the potential benefits of advanced electrophysiological techniques in managing complex cases. This report highlights the importance of a multidisciplinary approach in diagnosing and treating cardiac manifestations in patients with Friedreich ataxia, as well as the efficacy of 3D mapping technology in guiding successful ablation therapies. [ABSTRACT FROM AUTHOR]

Abstract Friedreich ataxia (FRDA) is a life-threatening hereditary ataxia; its incidence is 1:50,000 individuals in the Caucasian population. A unique therapeutic drug for FRDA, the antioxidant Omaveloxolone, has been recently approved by the US Food and Drug Administration (FDA). FRDA is a multi-systemic neurodegenerative disease; in addition to a progressive neurodegeneration, FRDA is characterized by hypertrophic cardiomyopathy, diabetes mellitus and musculoskeletal deformities. Cardiomyopathy is the predominant cause of premature death. The onset of FRDA typically occurs between the ages of 5 and 15. Given the complexity and heterogeneity of clinical features and the variability of their onset, the identification of biomarkers capable of assessing disease progression and monitoring the efficacy of treatments is essential to facilitate decision making in clinical practice. We conducted an RNA-seq analysis in peripheral blood mononuclear cells from FRDA patients and healthy donors, identifying a signature of small non-coding RNAs (sncRNAs) capable of distinguishing healthy individuals from the majority of FRDA patients. Among the differentially expressed sncRNAs, microRNAs are a class of small non-coding endogenous RNAs that regulate posttranscriptional silencing of target genes. In FRDA plasma samples, hsa-miR-148a-3p resulted significantly upregulated. The analysis of the Receiver Operating Characteristic (ROC) curve, combining the circulating expression levels of hsa-miR-148a-3p and hsa-miR-223-3p (previously identified by our group), revealed an Area Under the Curve (AUC) of 0.86 (95%, Confidence Interval 0.77–0.95; p-value

Background: Calcitriol, the active form of vitamin D (also known as 1,25‐dihydroxycholecalciferol), improves the phenotype and increases frataxin levels in cell models of Friedreich ataxia (FRDA). Objectives: Based on these results, we aimed measuring the effects of a calcitriol dose of 0.25 mcg/24h in the neurological function and frataxin levels when administered to FRDA patients for a year. Methods: 20 FRDA patients where recluted and 15 patients completed the treatment for a year. Evaluations of neurological function changes (SARA scale, 9‐HPT, 8‐MWT, PATA test) and quality of life (Barthel Scale and Short Form (36) Health Survey [SF‐36] quality of life questionnaire) were performed. Frataxin amounts were measured in isolated platelets obtained from these FRDA patients, from heterozygous FRDA carriers (relatives of the FA patients) and from non‐heterozygous sex and age matched controls. Results: Although the patients did not experience any observable neurological improvement, there was a statistically significant increase in frataxin levels from initial values, 5.5 to 7.0 pg/μg after 12 months. Differences in frataxin levels referred to total protein levels were observed among sex‐ and age‐matched controls (18.1 pg/μg), relative controls (10.1 pg/μg), and FRDA patients (5.7 pg/μg). The treatment was well tolerated by most patients, and only some of them experienced minor adverse effects at the beginning of the trial. Conclusions: Calcitriol dosage used (0.25 mcg/24 h) is safe for FRDA patients, and it increases frataxin levels. We cannot rule out that higher doses administered longer could yield neurological benefits. © 2024 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society. [ABSTRACT FROM AUTHOR]

Background: Friedreich ataxia is a rare genetic disorder associated with progressive mitochondrial dysfunction leading to widespread sequelae including ataxia, muscle weakness, hypertrophic cardiomyopathy, diabetes mellitus, and neuromuscular scoliosis. Children with Friedreich ataxia are at high risk for periprocedural complications during posterior spinal fusion due to their comorbidities. Aim: To describe our single‐center perioperative management of patients with Friedreich ataxia undergoing posterior spinal fusion. Methods: Adolescent patients with Friedreich ataxia presenting for spinal deformity surgery between 2007 and 2023 were included in this retrospective case series performed at the Children's Hospital of Philadelphia. Perioperative outcomes were reviewed along with preoperative characteristics, intraoperative anesthetic management, and postoperative medical management. Results: Seventeen patients were included in the final analysis. The mean age was 15 ± 2 years old and 47% were female. Preoperatively, 35% were wheelchair dependent, 100% had mild‐to‐moderate hypertrophic cardiomyopathy with preserved systolic function and no left ventricular outflow tract obstruction, 29% were on cardiac medications, and 29% were on pain medications. Intraoperatively, 53% had transesophageal echocardiography monitoring; 12% had changes in volume status on echo but no changes in function. Numerous combinations of total intravenous anesthetic agents were used, most commonly propofol, remifentanil, and ketamine. Baseline neuromonitoring signals were poor in four patients and one patient lost signals, resulting in 4 (24%) wake‐up tests. The majority (75%) were extubated in the operating room. Postoperative complications were high (88%) and ranged from minor complications like nausea/vomiting (18%) to major complications like hypotension/tachycardia (29%) and need for extracorporeal membrane oxygenation support in one patient (6%). Conclusions: Patients with Friedreich ataxia are at high risk for perioperative complications when undergoing posterior spinal fusion and coordinated multidisciplinary care is required at each stage. Future research should focus on the utility of intraoperative echocardiography, optimal anesthetic agent selection, and targeted fluid management to reduce postoperative cardiac complications. [ABSTRACT FROM AUTHOR]

Friedreich ataxia (FRDA) is a life-threatening hereditary ataxia; its incidence is 1:50,000 individuals in the Caucasian population. A unique therapeutic drug for FRDA, the antioxidant Omaveloxolone, has been recently approved by the US Food and Drug Administration (FDA). FRDA is a multi-systemic neurodegenerative disease; in addition to a progressive neurodegeneration, FRDA is characterized by hypertrophic cardiomyopathy, diabetes mellitus and musculoskeletal deformities. Cardiomyopathy is the predominant cause of premature death. The onset of FRDA typically occurs between the ages of 5 and 15. Given the complexity and heterogeneity of clinical features and the variability of their onset, the identification of biomarkers capable of assessing disease progression and monitoring the efficacy of treatments is essential to facilitate decision making in clinical practice. We conducted an RNA-seq analysis in peripheral blood mononuclear cells from FRDA patients and healthy donors, identifying a signature of small non-coding RNAs (sncRNAs) capable of distinguishing healthy individuals from the majority of FRDA patients. Among the differentially expressed sncRNAs, microRNAs are a class of small non-coding endogenous RNAs that regulate posttranscriptional silencing of target genes. In FRDA plasma samples, hsa-miR-148a-3p resulted significantly upregulated. The analysis of the Receiver Operating Characteristic (ROC) curve, combining the circulating expression levels of hsa-miR-148a-3p and hsa-miR-223-3p (previously identified by our group), revealed an Area Under the Curve (AUC) of 0.86 (95%, Confidence Interval 0.77–0.95; p-value < 0.0001). An in silico prediction analysis indicated that the IL6ST gene, an interesting marker of neuroinflammation in FRDA, is a common target gene of both miRNAs. Our findings support the evaluation of combined expression levels of different circulating miRNAs as potent epi-biomarkers in FRDA. Moreover, we found hsa-miR-148a-3p significantly over-expressed in Intermediate and Late-Onset Friedreich Ataxia patients' group (IOG and LOG, respectively) compared to healthy individuals, indicating it as a putative prognostic biomarker in this pathology. [ABSTRACT FROM AUTHOR]

Friedreich ataxia (FA) is a rare neurodegenerative disease caused by decreased levels of the mitochondrial protein frataxin. Frataxin has been related in iron homeostasis, energy metabolism, and oxidative stress. Ferroptosis has recently been shown to be involved in FA cellular degeneration; however, its role in dorsal root ganglion (DRG) sensory neurons, the cells that are affected the most and the earliest, is mostly unknown. In this study, we used primary cultures of frataxin-deficient DRG neurons as well as DRG from the FXNI151F mouse model to study ferroptosis and its regulatory pathways. A lack of frataxin induced upregulation of transferrin receptor 1 and decreased ferritin and mitochondrial iron accumulation, a source of oxidative stress. However, there was impaired activation of NRF2, a key transcription factor involved in the antioxidant response pathway. Decreased total and nuclear NRF2 explains the downregulation of both SLC7A11 (a member of the system Xc, which transports cystine required for glutathione synthesis) and glutathione peroxidase 4, responsible for increased lipid peroxidation, the main markers of ferroptosis. Such dysregulation could be due to the increase in KEAP1 and the activation of GSK3β, which promote cytosolic localization and degradation of NRF2. Moreover, there was a deficiency in the LKB1/AMPK pathway, which would also impair NRF2 activity. AMPK acts as a positive regulator of NRF2 and it is activated by the upstream kinase LKB1. The levels of LKB1 were reduced when frataxin decreased, in agreement with reduced pAMPK (Thr172), the active form of AMPK. SIRT1, a known activator of LKB1, was also reduced when frataxin decreased. MT-6378, an AMPK activator, restored NRF2 levels, increased GPX4 levels and reduced lipid peroxidation. In conclusion, this study demonstrated that frataxin deficiency in DRG neurons disrupts iron homeostasis and the intricate regulation of molecular pathways affecting NRF2 activation and the cellular response to oxidative stress, leading to ferroptosis.

Friedreich ataxia is a hereditary neurodegenerative disorder resulting from reduced levels of the protein frataxin due to an expanded GAA repeat in the FXN gene. This deficiency causes progressive degeneration of specific neuronal populations in the cerebellum and the consequent loss of movement coordination and equilibrium, which are some of the main symptoms observed in affected individuals. Like in other neurodegenerative diseases, previous studies suggest that glial cells could be involved in the neurodegenerative process and disease progression in patients with Friedreich ataxia.In this work, we followed and characterized the progression of changes in the cerebellar cortex in the latest version of Friedreich ataxia humanized mouse model, YG8–800 (Fxnnull:YG8s(GAA)>800), which carries a human FXN transgene containing >800 GAA repeats.Comparative analyses of behavioral, histopathological, and biochemical parameters were conducted between the control strain Y47R and YG8–800 mice at different time points. Our findings revealed that YG8–800 mice exhibit an ataxic phenotype characterized by poor motor coordination, decreased body weight, cerebellar atrophy, neuronal loss, and changes in synaptic proteins. Additionally, early activation of glial cells, predominantly astrocytes and microglia, was observed preceding neuronal degeneration, as was increased expression of key proinflammatory cytokines and downregulation of neurotrophic factors.Together, our results show that the YG8–800 mouse model exhibits a stronger phenotype than previous experimental murine models, reliably recapitulating some of the features observed in humans. Accordingly, this humanized model could represent a valuable tool for studying Friedreich ataxia molecular disease mechanisms and for preclinical evaluation of possible therapies.

BACKGROUND: Individuals with Friedreich ataxia (FRDA) can find it difficult to access specialized clinical care. To facilitate best practice in delivering healthcare for FRDA, clinical management guidelines (CMGs) were developed in 2014. However, the lack of high-certainty evidence and the inadequacy of accepted metrics to measure health status continues to present challenges in FRDA and other rare diseases. To overcome these challenges, the Grading of Recommendations Assessment and Evaluation (GRADE) framework for rare diseases developed by the RARE-Bestpractices Working Group was adopted to update the clinical guidelines for FRDA. This approach incorporates additional strategies to the GRADE framework to support the strength of recommendations, such as review of literature in similar conditions, the systematic collection of expert opinion and patient perceptions, and use of natural history data. METHODS: A panel representing international clinical experts, stakeholders and consumer groups provided oversight to guideline development within the GRADE framework. Invited expert authors generated the Patient, Intervention, Comparison, Outcome (PICO) questions to guide the literature search (2014 to June 2020). Evidence profiles in tandem with feedback from individuals living with FRDA, natural history registry data and expert clinical observations contributed to the final recommendations. Authors also developed best practice statements for clinical care points that were considered self-evident or were not amenable to the GRADE process. RESULTS: Seventy clinical experts contributed to fifteen topic-specific chapters with clinical recommendations and/or best practice statements. New topics since 2014 include emergency medicine, digital and assistive technologies and a stand-alone section on mental health. Evidence was evaluated according to GRADE criteria and 130 new recommendations and 95 best practice statements were generated. DISCUSSION AND CONCLUSION: Evidence-based CMGs are required to ensure the best clinical care for people with FRDA. Adopting the GRADE rare-disease framework enabled the development of higher quality CMGs for FRDA and allows individual topics to be updated as new evidence emerges. While the primary goal of these guidelines is better outcomes for people living with FRDA, the process of developing the guidelines may also help inform the development of clinical guidelines in other rare diseases.

BACKGROUND AND OBJECTIVES: The understanding of the natural history of Friedreich ataxia (FRDA) has improved considerably recently, but patterns of neurologic deterioration are not fully clarified, compromising the assessment of the clinical relevance of effects and guidance for study design. The goal of this study was to acknowledge the broad genetic diversity of the population, especially for younger individuals, and to provide analyses stratified by age to guide population selection in future studies. METHODS: Based on a large natural history study, the FRDA Clinical Outcome Measures study that at the current data cut enrolled 1,115 participants, followed up for 5,287 yearly visits, we present results from the modified FRDA Rating Scale and its subscores. The secondary outcomes included the patient-reported activities of daily living scale, the timed 25-foot walk, and the 9-hole peg test. Long-term progression was modeled using slope analyses within early-onset, typical-onset, intermediate-onset, and late-onset FRDA. To reflect recruitment in clinical trials, short-term changes were analyzed within age-based subpopulations. All analyses were stratified by ambulation status. RESULTS: Long-term progression models stratified by disease severity indicated highly differential disease progression, especially at earlier ages at onset. In the ambulatory phase, decline was driven by axial items assessed by the Upright Stability subscore of the mFARS. The analyses of short-term changes showed slower progression with increasing population age due to decreasing genetic severity. Future clinical studies could reduce population diversity, interpatient variability, and the risk of imbalanced treatment groups by selecting the study population based on the functional capacity (e.g., ambulatory status) and by strict age-based stratification. DISCUSSION: The understanding of the diversity within FRDA populations and their patterns of functional decline provides an essential foundation for future clinical trial design including patient selection and facilitates the interpretation of the clinical relevance of progression detected in FRDA.

Quantitative measurement of physical activity may complement neurological evaluation and provide valuable information on patients' daily life. We evaluated longitudinal changes of physical activity in patients with Friedreich ataxia (FRDA) using remote monitoring with wearable sensors. We performed an observational study in 26 adult patients with FRDA and 13 age-sex matched healthy controls (CTR). Participants were asked to wear two wearable sensors, at non-dominant wrist and at waist, for 7 days during waking hours. Evaluations were performed at baseline and at 1-year follow-up. We analysed the percentage of time spent in sedentary or physical activities, the Vector Magnitude on the 3 axes (VM3), and average number of steps/min. Study participants were also evaluated with ataxia clinical scales and functional tests for upper limbs dexterity and walking capability. Baseline data showed that patients had an overall reduced level of physical activity as compared to CTR. Accelerometer-based measures were highly correlated with clinical scales and disease duration in FRDA. Significantly changes from baseline to l-year follow-up were observed in patients for the following measures: (i) VM3; (ii) percentage of sedentary and light activity, and (iii) percentage of Moderate-Vigorous Physical Activity (MVPA). Reduction in physical activity corresponded to worsening in gait score of the Scale for Assessment and Rating of Ataxia. Real-life activity monitoring is feasible and well tolerated by patients. Accelerometer-based measures can quantify disease progression in FRDA over 1 year, providing objective information about patient's motor activities and supporting the usefulness of these data as complementary outcome measure in interventional trials. [ABSTRACT FROM AUTHOR]

Friedreich ataxia (FRDA) is a rare autosomal recessive disease, marked by loss of coordination as well as impaired neurological, endocrine, orthopedic, and cardiac function. There are many symptomatic medications for FRDA, and many clinical trials have been performed, but only one FDA-approved medication exists. The relative absence of the frataxin protein (FXN) in FRDA causes mitochondrial dysfunction, resulting in clinical manifestations. Currently, the only approved treatment for FRDA is an Nrf2 activator called omaveloxolone (Skyclarys). Patients with FRDA also rely on various symptomatic medications for treatment. Because there is only one approved medication for FRDA, clinical trials continue to advance in FRDA. Although some trials have not met their endpoints, many current and upcoming clinical trials provide exciting possibilities for the treatment of FRDA. The approval of omaveloxolone provides a major advance in FRDA therapeutics. Although well tolerated, it is not curative. Reversal of deficient frataxin levels with gene therapy, protein replacement, or epigenetic approaches provides the most likely prospect for enduring, disease-modifying therapy in the future. [ABSTRACT FROM AUTHOR]

Background: The neurological phenotype of Friedreich ataxia (FRDA) is characterized by neurodegeneration and neuroinflammation in the cerebellum and brainstem. Novel neuroimaging approaches quantifying brain free‐water using diffusion magnetic resonance imaging (dMRI) are potentially more sensitive to these processes than standard imaging markers. Objectives: To quantify the extent of free‐water and microstructural change in FRDA‐relevant brain regions using neurite orientation dispersion and density imaging (NODDI), and bitensor diffusion tensor imaging (btDTI). Method: Multi‐shell dMRI was acquired from 14 individuals with FRDA and 14 controls. Free‐water measures from NODDI (FISO) and btDTI (FW) were compared between groups in the cerebellar cortex, dentate nuclei, cerebellar peduncles, and brainstem. The relative sensitivity of the free‐water measures to group differences was compared to microstructural measures of NODDI intracellular volume, free‐water corrected fractional anisotropy, and conventional uncorrected fractional anisotropy. Results: In individuals with FRDA, FW was elevated in the cerebellar cortex, peduncles (excluding middle), dentate, and brainstem (P < 0.005). FISO was elevated primarily in the cerebellar lobules (P < 0.001). On average, FW effect sizes were larger than all other markers (mean ηρ2 = 0.43), although microstructural measures also had very large effects in the superior and inferior cerebellar peduncles and brainstem (ηρ2 > 0.37). Across all regions and metrics, effect sizes were largest in the superior cerebellar peduncles (ηρ2 > 0.46). Conclusions: Multi‐compartment diffusion measures of free‐water and neurite integrity distinguish FRDA from controls with large effects. Free‐water magnitude in the brainstem and cerebellum provided the greatest distinction between groups. This study supports further applications of multi‐compartment diffusion modeling, and investigations of free‐water as a measure of disease expression and progression in FRDA. © 2023 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society. [ABSTRACT FROM AUTHOR]

Friedreich's ataxia is degenerative disease frequently starting around puberty and it's characterized by a progressive gait ataxia, limb weakness, apparition of Babinsky sign, loss of deep tendon reflex, dysarthria and skeletal deformities. The development of vestibular pathology is common but not completely understood. A 16 years old woman with early vestibular defects in relation to a latter Friedreich's ataxia diagnosis is reported. [ABSTRACT FROM AUTHOR]

Background: A drug repositioning effort supported the possible use of the anti-HIV drug etravirine as a disease-modifying drug for Friedreich ataxia (FRDA). Etravirine increases frataxin protein and corrects the biochemical defects in cells derived from FRDA patients. Because of these findings, and since etravirine displays a favorable safety profile, we conducted a pilot open-label phase 2 clinical trial assessing the safety and potential efficacy of etravirine in FRDA patients. Methods: Thirty-five patients were stratified into three severity groups and randomized to etravirine 200 mg/day or 400 mg/day. They were treated for 4 months. Safety endpoints were the number and type of adverse events and number of dropouts. Efficacy endpoints were represented by changes in peak oxygen uptake and workload as measured by incremental exercise test, SARA score, cardiac measures, measures of QoL and disability. Data were collected 4 months before the start of the treatment (T − 4), at the start (T0), at the end (T4) and 4 months after the termination of the treatment (T + 4). Results: Etravirine was reasonably tolerated, and adverse events were generally mild. Four months of etravirine treatment did not significantly increase the peak oxygen uptake but was associated with a change in the progression of the SARA score (p value < 0.001), compared to the 4 months pre- and post-treatment. It also significantly increased peak workload (p value = 0.021). No changes in the cardiac measures were observed. Health and QoL measures showed a worsening at the suspension of the drug. Conclusions: In this open trial etravirine treatment was safe, reasonably well tolerated and appreciably improved neurological function and exercise performance. Even though a placebo effect cannot be ruled out, these results suggest that etravirine may represent a potential therapeutic agent in FRDA deserving testing in a randomized placebo-controlled clinical trial.

Abstract Friedreich ataxia (FRDA) is a rare genetic multisystem disorder caused by a pathological GAA trinucleotide repeat expansion in the FXN gene. The numerous drawbacks of historical cellular and rodent models of FRDA have caused difficulty in performing effective mechanistic and translational studies to investigate the disease. The recent discovery and subsequent development of induced pluripotent stem cell (iPSC) technology provides an exciting platform to enable enhanced disease modelling for studies of rare genetic diseases. Utilising iPSCs, researchers have created phenotypically relevant and previously inaccessible cellular models of FRDA. These models enable studies of the molecular mechanisms underlying GAA-induced pathology, as well as providing an exciting tool for the screening and testing of novel disease-modifying therapies. This review explores how the use of iPSCs to study FRDA has developed over the past decade, as well as discussing the enormous therapeutic potentials of iPSC-derived models, their current limitations and their future direction within the field of FRDA research. Graphical abstract

Quantitative measurement of physical activity may complement neurological evaluation and provide valuable information on patients’ daily life. We evaluated longitudinal changes of physical activity in patients with Friedreich ataxia (FRDA) using remote monitoring with wearable sensors. We performed an observational study in 26 adult patients with FRDA and 13 age-sex matched healthy controls (CTR). Participants were asked to wear two wearable sensors, at non-dominant wrist and at waist, for 7 days during waking hours. Evaluations were performed at baseline and at 1-year follow-up. We analysed the percentage of time spent in sedentary or physical activities, the Vector Magnitude on the 3 axes (VM3), and average number of steps/min. Study participants were also evaluated with ataxia clinical scales and functional tests for upper limbs dexterity and walking capability. Baseline data showed that patients had an overall reduced level of physical activity as compared to CTR. Accelerometer-based measures were highly correlated with clinical scales and disease duration in FRDA. Significantly changes from baseline to l-year follow-up were observed in patients for the following measures: (i) VM3; (ii) percentage of sedentary and light activity, and (iii) percentage of Moderate-Vigorous Physical Activity (MVPA). Reduction in physical activity corresponded to worsening in gait score of the Scale for Assessment and Rating of Ataxia. Real-life activity monitoring is feasible and well tolerated by patients. Accelerometer-based measures can quantify disease progression in FRDA over 1 year, providing objective information about patient’s motor activities and supporting the usefulness of these data as complementary outcome measure in interventional trials.

Gene therapy is a potential treatment for Friedreich ataxia, with multiple programs on the horizon. The purpose of this study was to collect opinions about gene therapy from individuals 14 years or older with Friedreich ataxia or parents/caregivers of Friedreich ataxia patients who were diagnosed as children 17 or younger. Participants were asked to complete a survey after reading brief educational materials regarding gene therapy. Most of the patients captured in this survey have an early-onset (classical) presentation of the disease. Participants expressed urgency in participating in gene therapy clinical trials despite the associated risks. About half of the respondents believed that gene therapy would cease progression or minimize symptoms, whereas nearly one-fourth expected to be cured. The survey also revealed how participants perceive their symptom burden, because a substantial majority reported that balance/walking issues most interfere with their quality of life and would be the symptom they would prioritize treating. Although not statistically significant, more caregivers prioritized treating cardiomyopathy than patients. This study provides valuable information on priorities, beliefs, and expectations regarding gene therapy and serves to guide future gene therapy opinion studies and gene therapy trial design.

Heart, dentate nucleus, and dorsal root ganglia (DRG) are targets of tissue damage in Friedreich ataxia (FA). This report summarizes the histology and histopathology of iron in the main tissues affected by FA. None of the affected anatomical sites reveals an elevation of total iron levels. In the myocardium, a small percentage of fibers shows iron-reactive granular inclusions. The accumulation of larger iron aggregates and fiber invasion cause necrosis and damage to the contractile apparatus. In the dentate nucleus, the principal FA-caused tissue injury is neuronal atrophy and grumose reaction. X-ray fluorescence mapping of iron in the dentate nucleus in FA shows retention of the metal in the center of the collapsed structure. Immunohistochemistry of ferritin, a surrogate marker of tissue iron, confirms strong expression in oligodendrocytes of the efferent white matter of the dentate nucleus and abundance of ferritin-positive microglia in the atrophic gray matter. Iron dysmetabolism in DRG is complex and consists of prominent expression of ferritin in hyperplastic satellite cells and residual nodules, also a loss of the iron export protein ferroportin from the cytoplasm of the remaining DRG nerve cells. [ABSTRACT FROM AUTHOR]

Introduction: The relevance of rehabilitation in progressive neurological disorders, such as Friedreich's Ataxia (FRDA), has yet to be convincingly proven. FRDA is characterized by ataxia, loss of gait, scoliosis, cardiomyopathy, dysarthria and dysphagia, with reduced life expectancy. The disease onset is usually in adolescence, leading to progressive disability. Omaveloxolone has been recently approved as the first pharmacological treatment for FRDA in adults and adolescents aged 16 years and older. Regarding non-pharmacological therapies, neurorehabilitation is a valuable aid in addressing the symptoms and in maintaining the residual functioning. We performed a prospective observational cohort study to evaluate the efficacy of inpatient rehabilitation (IR) for people with FRDA. Methods: A total of 42 individuals (29 adults and 13 children) with FRDA were recruited. There were 27 ambulant and 15 non-ambulant participants. The patients underwent IR of 3 and 4 weeks in children and adults, respectively. The IR treatment was designed to be applied within a multidisciplinary setting, so FRDA patients underwent, in addition to physiotherapy, also occupational therapy, practical manual activities and psychological support aiming to enhance transferable skills useful in the activities of daily living. The primary outcome was the Scale for the Assessment and Rating of Ataxia (SARA). Other measures were: Friedreich Ataxia Rating Scale (FARS) and Nine Hole Peg Test (NHPT). Furthermore, we used the 6 Minute Walk Test (6MWT), the Timed Up and Go (TUG) and the Berg Balance Scale (BBS) only on ambulant subjects. Outcomes were evaluated at baseline and at the end of the treatment. Results: We report that the IR significantly improves motor performance and ataxia symptoms in patients with FRDA. Our study shows significant functional improvement in all the outcome measures used, except for NHPT bilaterally. FARS and SARA scores post-IR are significatively reduced when compared (p < 0.001). Discussion: We demonstrate that IR programs in FRDA can provide a meaningful clinical improvement in terms of outcome measures. These findings could be useful when approaching progressive neurological disorders. [ABSTRACT FROM AUTHOR]

OBJECTIVE: The objective of this study was to characterize the incidence and progression of scoliosis in the natural history of Friedreichs ataxia (FRDA) and document the factors leading to the requirement for corrective surgery. METHODS: Data on the prevalence of scoliosis and scoliosis surgery from up to 17 years of follow-up collected during a large natural history study in FRDA (1116 patients at 4928 visits) were summarized descriptively and subjected to time to event analyses. RESULTS: Well over 90% of early or typical FRDA patients (as determined by age of onset) developed intermediate to severe scoliosis, while patients with a later onset (>14 years) had no or much lower prevalence of scoliosis. Diagnosis of scoliosis occurs during the onset of ataxia and in rare cases even prior to that. Major progression follows throughout the growth phase and puberty, leading to the need for surgical intervention in more than 50% of individuals in the most severe subgroup. The youngest patients appear to delay surgery until the end of the growth period, leading to further progression before surgical intervention. Age of onset of FRDA before or after reaching 15 years sharply separated severe and relatively mild incidence and progression of scoliosis. INTERPRETATION: Scoliosis is an important comorbidity of FRDA. Our comprehensive documentation of scoliosis progression in this natural history study provides a baseline for comparison as novel treatments become available.

The dynamic regulation of endothelial pathophenotypes in pulmonary hypertension (PH) remains undefined. Cellular senescence is linked to PH with intracardiac shunts; however, its regulation across PH subtypes is unknown. Since endothelial deficiency of iron-sulfur (Fe-S) clusters is pathogenic in PH, we hypothesized that a Fe-S biogenesis protein, frataxin (FXN), controls endothelial senescence. An endothelial subpopulation in rodent and patient lungs across PH subtypes exhibited reduced FXN and elevated senescence. In vitro, hypoxic and inflammatory FXN deficiency abrogated activity of endothelial Fe-S-containing polymerases, promoting replication stress, DNA damage response, and senescence. This was also observed in stem cell-derived endothelial cells from Friedreich's ataxia (FRDA), a genetic disease of FXN deficiency, ataxia, and cardiomyopathy, often with PH. In vivo, FXN deficiency-dependent senescence drove vessel inflammation, remodeling, and PH, whereas pharmacologic removal of senescent cells in Fxn-deficient rodents ameliorated PH. These data offer a model of endothelial biology in PH, where FXN deficiency generates a senescent endothelial subpopulation, promoting vascular inflammatory and proliferative signals in other cells to drive disease. These findings also establish an endothelial etiology for PH in FRDA and left heart disease and support therapeutic development of senolytic drugs, reversing effects of Fe-S deficiency across PH subtypes.

OBJECTIVE: Friedreich ataxia (FA) is a progressive genetic neurodegenerative disorder with no approved treatment. Omaveloxolone, an Nrf2 activator, improves mitochondrial function, restores redox balance, and reduces inflammation in models of FA. We investigated the safety and efficacy of omaveloxolone in patients with FA. METHODS: We conducted an international, double-blind, randomized, placebo-controlled, parallel-group, registrational phase 2 trial at 11 institutions in the United States, Europe, and Australia (NCT02255435, EudraCT2015-002762-23). Eligible patients, 16 to 40 years of age with genetically confirmed FA and baseline modified Friedreichs Ataxia Rating Scale (mFARS) scores between 20 and 80, were randomized 1:1 to placebo or 150mg per day of omaveloxolone. The primary outcome was change from baseline in the mFARS score in those treated with omaveloxolone compared with those on placebo at 48 weeks. RESULTS: One hundred fifty-five patients were screened, and 103 were randomly assigned to receive omaveloxolone (n = 51) or placebo (n = 52), with 40 omaveloxolone patients and 42 placebo patients analyzed in the full analysis set. Changes from baseline in mFARS scores in omaveloxolone (-1.55 ± 0.69) and placebo (0.85 ± 0.64) patients showed a difference between treatment groups of -2.40 ± 0.96 (p = 0.014). Transient reversible increases in aminotransferase levels were observed with omaveloxolone without increases in total bilirubin or other signs of liver injury. Headache, nausea, and fatigue were also more common among patients receiving omaveloxolone. INTERPRETATION: In the MOXIe trial, omaveloxolone significantly improved neurological function compared to placebo and was generally safe and well tolerated. It represents a potential therapeutic agent in FA. ANN NEUROL 2021;89:212-225.

Previously we showed that dimethyl fumarate (DMF) dose-dependently increased mitochondrial gene expression and function in cells and might be considered as a therapeutic for inherited mitochondrial disease, including Friedreich's ataxia (FA). Here we tested DMF's ability to dose-dependently increase mitochondrial function, mitochondrial gene expression (frataxin and cytochrome oxidase protein) and mitochondrial copy number in C57BL6 wild-type mice and the FXNKD mouse model of FA. We first dosed DMF at 0-320 mg/kg in C57BL6 mice and observed significant toxicity above 160 mg/kg orally, defining the maximum tolerated dose. Oral dosing of C57BL6 mice in the range 0-160 mg/kg identified a maximum increase in aconitase activity and mitochondrial gene expression in brain and quadriceps at 110 mg/kg DMF, thus defining the maximum effective dose (MED). The MED of DMF in mice overlaps the currently approved human-equivalent doses of DMF prescribed for multiple sclerosis (480 mg/day) and psoriasis (720 mg/day). In the FXNKD mouse model of FA, which has a doxycycline-induced deficit of frataxin protein, we observed significant decreases of multiple mitochondrial parameters, including deficits in brain mitochondrial Complex 2, Complex 4 and aconitase activity, supporting the idea that frataxin deficiency reduces mitochondrial gene expression, mitochondrial functions and biogenesis. About 110 mg/kg of oral DMF rescued these enzyme activities in brain and rescued frataxin and cytochrome oxidase expression in brain, cerebellum and quadriceps muscle of the FXNKD mouse model. Taken together, these results support the idea of using fumarate-based molecules to treat FA or other mitochondrial diseases.

Objectives: Friedreich Ataxia (FRDA) is the most common recessive ataxia disorder. Yet, little is known of the prevalence in Sweden. In the future, there may be effective disease-modifying therapies, and use of clinical rating scales as well as possible biomarkers in serum or cerebrospinal fluid may be of importance. We evaluated the axonal protein neurofilament light in plasma (p-NfL) as a possible biomarker for disease severity in FRDA. Materials & methods: We searched for all possible genetically confirmed FRDA cases in the Västra Götaland Region (VGR) of Sweden, and investigated each patient clinically and obtained blood sample for analysis of p-NfL. Results: We found eight patients corresponding to 1/170.000 adults in the VGR, and 5 of these participated in the study. Three out of the five FRDA patients displayed a small or moderate increase in the p-NfL value, compared to the age-adjusted cut-offs for p-NfL established in the Clinical Neurochemistry Laboratory at our hospital. The two others were the oldest and most severely affected, displayed normal values according the cut-off values. The cohort is too small to make any statistically significant correlation between the five p-NfL values with regard to disease severity. Conclusions: FRDA is less prevalent in our region of Sweden than could be assumed. In concordance with previous studies from other authors, we find that p-NfL may be increased in patients with FRDA, but less so in older more clinically affected patients. Thus, we conclude that on an individual basis, p-NFL is of uncertain clinical value as a suitable biomarker.

The exciting news about the US FDA approval of omaveloxolone as the first-ever drug to be approved for an inherited ataxia is welcome news for patients and families that deal with this devastating disease as well as for health care providers and investigators with an interest in this and other rare diseases. This event is the culmination of long and fruitful collaboration between patients, their families, clinicians, laboratory researchers, patient advocacy organizations, industry, and regulatory agencies. The process has generated intense discussion about outcome measures, biomarkers, trial design, and the nature of approval process for such diseases. It also has brought hope and enthusiasm for increasingly better therapies for genetic diseases in general. [ABSTRACT FROM AUTHOR]

IntroductionThe relevance of rehabilitation in progressive neurological disorders, such as Friedreich’s Ataxia (FRDA), has yet to be convincingly proven. FRDA is characterized by ataxia, loss of gait, scoliosis, cardiomyopathy, dysarthria and dysphagia, with reduced life expectancy. The disease onset is usually in adolescence, leading to progressive disability. Omaveloxolone has been recently approved as the first pharmacological treatment for FRDA in adults and adolescents aged 16 years and older. Regarding non-pharmacological therapies, neurorehabilitation is a valuable aid in addressing the symptoms and in maintaining the residual functioning. We performed a prospective observational cohort study to evaluate the efficacy of inpatient rehabilitation (IR) for people with FRDA.MethodsA total of 42 individuals (29 adults and 13 children) with FRDA were recruited. There were 27 ambulant and 15 non-ambulant participants. The patients underwent IR of 3 and 4 weeks in children and adults, respectively. The IR treatment was designed to be applied within a multidisciplinary setting, so FRDA patients underwent, in addition to physiotherapy, also occupational therapy, practical manual activities and psychological support aiming to enhance transferable skills useful in the activities of daily living. The primary outcome was the Scale for the Assessment and Rating of Ataxia (SARA). Other measures were: Friedreich Ataxia Rating Scale (FARS) and Nine Hole Peg Test (NHPT). Furthermore, we used the 6 Minute Walk Test (6MWT), the Timed Up and Go (TUG) and the Berg Balance Scale (BBS) only on ambulant subjects. Outcomes were evaluated at baseline and at the end of the treatment.ResultsWe report that the IR significantly improves motor performance and ataxia symptoms in patients with FRDA. Our study shows significant functional improvement in all the outcome measures used, except for NHPT bilaterally. FARS and SARA scores post-IR are significatively reduced when compared (p

Friedreich's ataxia (FRDA) is the most common inherited recessive ataxia. Cardiomyopathy (CM) with myocardial hypertrophy is the predominant cause of death. The presence of CM is variable and the risk factors for cardiac involvement are not entirely clear. Markers of collagen degradation, such as C-terminal cross-linked telopeptide of type I collagen (CTX-I), seem to be associated with unfavorable cardiovascular outcomes. The aim of our study was to measure serum CTX-I as a marker of cardiac fibrosis in FRDA patients. We measured serum CTX value in twenty-five FRDA patients (mean age, 31.3 ± 14.7 years) and nineteen healthy controls (mean age, 34.0 ± 13.5 years). Patients underwent echocardiography and SARA scale evaluation. CTX values were significantly higher in the patients than in the control group (31.82 ± 2.27 vs 16.44 ± 1.6 μg/L; p = 0.006). CTX-I was inversely correlated with age (R = − 0,535; n = 44; p < 0.001). The regression model identified disease duration and TT3 levels to be independent predictors of CTX-I (model R2 = 0.938; intercept − 64.0, p = 0.071; disease duration coefficient = − 2.34, p = 0.005; TT3 coefficient = 127.17, p = 0.011). CTX-I, a biomarkers of collagen turnover, is elevated in FRDA and should provide complementary information to identify patients with high cardiological risk even if longitudinal studies are needed to define the role of this serologic marker of collagen metabolism in the natural history of cardiomyopathy in FRDA patients. [ABSTRACT FROM AUTHOR]

Scientists and pharmaceutical companies are working toward delivering gene therapy (GT) for Friedreich ataxia (FRDA). Understanding the views of people with lived experience of FRDA and their parents toward GT is essential to inform trial design and identify potential barriers to participation in clinical trials. The goals of this study were to identify the attitudes toward GT held by individuals with FRDA and parents of individuals with FRDA, and to explore how these may impact future trials for this condition. Audiorecorded, semistructured, qualitative interviews with 19 Australians explored experiences of FRDA, knowledge about clinical trials, views on GT, including risks and benefits, and potential barriers to participation in trials. Participants included thirteen individuals living with FRDA aged between 15–43 years, and six parents of children with FRDA aged 4–12 years of age. Thematic analysis of the interviews identified six main themes. Findings from this study indicate there is strong desire for information regarding GT in FRDA, however the current level of uncertainty around GT makes decision making challenging. The desire to maintain functional status and avoid additional risk of deterioration from an investigational treatment was apparent. Importantly, neurological targets were identified as preferred for GT trials. Further research is required to identify if attitudes and perceptions differ according to geographical location and disease stage. [ABSTRACT FROM AUTHOR]

Friedreich ataxia (FRDA) is a rare genetic multisystem disorder caused by a pathological GAA trinucleotide repeat expansion in the FXN gene. The numerous drawbacks of historical cellular and rodent models of FRDA have caused difficulty in performing effective mechanistic and translational studies to investigate the disease. The recent discovery and subsequent development of induced pluripotent stem cell (iPSC) technology provides an exciting platform to enable enhanced disease modelling for studies of rare genetic diseases. Utilising iPSCs, researchers have created phenotypically relevant and previously inaccessible cellular models of FRDA. These models enable studies of the molecular mechanisms underlying GAA-induced pathology, as well as providing an exciting tool for the screening and testing of novel disease-modifying therapies. This review explores how the use of iPSCs to study FRDA has developed over the past decade, as well as discussing the enormous therapeutic potentials of iPSC-derived models, their current limitations and their future direction within the field of FRDA research. [ABSTRACT FROM AUTHOR]