Facioscapulohumeral Muscular Dystrophy Patients Research Articles

Treatment Approaches for Altered Facial Expression: A Systematic Review in Facioscapulohumeral Muscular Dystrophy and Other Neurological Diseases.

Facial weakness is a key feature of facioscapulohumeral muscular dystrophy (FSHD) and may lead to altered facial expression and subsequent psychosocial impairment. There is no cure and supportive treatments focus on optimizing physical fitness and compensation of functional disabilities. We hypothesize that symptomatic treatment options and psychosocial interventions for other neurological diseases with altered facial expression could be applicable to FSHD. Therefore, the aim of this review is to collect symptomatic treatment approaches that target facial muscle function and psychosocial interventions in various neurological diseases with altered facial expression in order to discuss the applicability to FSHD. A systematic search was performed. Selected studies had to include FSHD, Bell's palsy, Moebius syndrome, myotonic dystrophy type 1, or Parkinson's disease and treatment options which target altered facial expression. Data was extracted for study and patients' characteristics, outcome assessment tools, treatment, outcome of facial expression and or psychosocial functioning. Forty studies met the inclusion criteria, of which only three studies included FSHD patients exclusively. Most, twenty-one, studies were performed in patients with Bell's palsy. Studies included twelve different therapy categories and results were assessed with different outcomes measures. Five therapy categories were considered applicable to FSHD: training of (non-verbal) communication compensation strategies, speech training, physical therapy, conference attendance, and smile restoration surgery. Further research is needed to establish the effect of these therapies in FSHD. We recommend to include outcome measures in these studies that cover at least cosmetic, functional, communication, and quality of life domains.

Facioscapulohumeral Muscular Dystrophy European Patient Survey: Assessing Patient Reported Disease Burden and Preferences in Clinical Trial Participation.

Facioscapulohumeral muscular dystrophy (FSHD) is a genetic disorder characterized by progressive muscle weakness leading to permanent disability. There are no curative treatments, however, there are several upcoming clinical trials testing new therapies in FSHD. This study aimed to explore the disease burden and patient preferences of people with FSHD to ensure that clinical trials can be designed to include outcome measures that are relevant and important to patients. A survey was developed with a steering committee clinicians and physiotherapists with relevant experience in the disease, patient representatives, a registry expert and industry consultants. Themes of the survey included; participant demographics, disease progression and impact on function, factors encouraging or discouraging clinical trial participation, and positive outcomes of a clinical trial. 1147 participants responded to the online survey, representing 26 countries across Europe and a range of disease severities. The study highlighted the key symptoms causing concern for FSHD patients - muscle weakness and mobility issues - reflecting what participants want targeted for future therapies. The need for clear information and communication throughout clinical trials was emphasised. Factors most encouraging trial participation included access to new investigational therapies, access to trial results and benefits for the FSHD community. Factors most discouraging trial participation included travel related issues and fear of side effects. The results from this study identify the patient reported burden of FSHD and should provide researchers and industry with areas of therapeutic research that would be meaningful to patients, as well as supporting the development of patient centric outcome measures in clinical trials.

The complementary use of muscle ultrasound and MRI in FSHD: Early versus later disease stage follow-up

ObjectivesMuscle MRI and ultrasound provide complementary techniques for characterizing muscle changes and tracking disease progression in facioscapulohumeral muscular dystrophy (FSHD). In this cohort study, we provide longitudinal data that compares both imaging modalities head-to-head. MethodsFSHD patients were assessed at baseline and after five years. Standardized muscle MRI and ultrasound images of five leg muscles were assessed bilaterally. Fat replacement was quantified using MRI fat-fraction (FF) and ultrasound Heckmatt and echogenicity z-scores (EZ-score). Muscle edema was evaluated using T2-weighted turbo inversion recovery magnitude (TIRM) MRI. ResultsTwenty FSHD patients were included. Muscles with normal baseline imaging showed increases in ultrasound EZ-scores (≥1; in 17%) more often than MRI FF increases (≥10%; in 7%) over time. Muscles with only baseline ultrasound abnormalities often showed considerable FF increases (in 22%), and TIRM positivity at follow-up (44%). Muscles with increased FF at baseline showed stable (80%) or increasing FF (20%) over time. EZ-scores of those muscles either increased (23%), decreased (33%) or remained stable (44%). ConclusionsMuscle ultrasound may capture accelerated pathological muscle changes in FSHD in early disease, while muscle MRI appears better-suited to detecting and monitoring pathology in later stages. SignificanceOur results help establish each techniques’ optimal use as imaging biomarker.

Living with facioscapulohumeral muscular dystrophy during the first two COVID-19 outbreaks: a repeated patient survey in the Netherlands.

Patients with facioscapulohumeral dystrophy (FSHD) suffer from slowly progressive muscle weakness. Approximately 20% of FSHD patients end up wheelchair-dependent. FSHD patients benefit from physical activity to maintain their muscle strength as much as possible. The impact of the COVID-19 pandemic on the health of FSHD patients was unknown. This study assessed changes in daily care received, perceived psychosocial stress, and worsening of FSHD complaints in 2020. Furthermore, we compared COVID-19 infection incidence and severity of symptoms between FSHD patients and non-FSHD housemates. Three online survey rounds were sent out to all adult participants of the Dutch FSHD registry regarding daily care received, perceived psychosocial stress, COVID-19 infection rate, and COVID-19 symptoms severity. They also included COVID-19-related questions regarding the participants' housemates, which served as control group. Participation rate was 210 (61%), 186 (54%), and 205 (59%) for survey 1, 2, and 3, respectively. Care reduction was reported by 42.7%, 40%, and 28.8% of the participants in the respective surveys. Perceived psychosocial stress increased in 44%, 30%, and 40% of the participants. Compared to the 197 non-FSHD housemates, the 213 FSHD patients reported more possibly COVID-19-related symptoms (27% vs. 39%, p = 0.017) of mostly minimal severity (63%). No difference in (possible) COVID-19 infection incidence rates was found (2.0% vs. 2.8%, p = 0.527). The COVID-19 pandemic negatively impacted care received and increased perceived psychosocial stress in FSHD patients. However, COVID-19 infection incidence in FSHD patients was similar to their non-FSHD housemates.

A Targeted Approach for Evaluating DUX4-Regulated Proteins as Potential Serum Biomarkers for Facioscapulohumeral Muscular Dystrophy Using Immunoassay Proteomics.

Facioscapulohumeral muscular dystrophy (FSHD) is a progressive myopathy caused by misexpression of the double homeobox 4 (DUX4) embryonic transcription factor in skeletal muscle. Identifying quantitative and minimally invasive FSHD biomarkers to report on DUX4 activity will significantly accelerate therapeutic development. The goal of this study was to analyze secreted proteins known to be induced by DUX4 using the commercially available Olink Proteomics platform in order to identify potential blood-based molecular FSHD biomarkers. We used high-throughput, multiplex immunoassays from Olink Proteomics to measure the levels of several known DUX4-induced genes in a cellular myoblast model of FSHD, in FSHD patient-derived myotube cell cultures, and in serum from individuals with FSHD. Levels of other proteins on the Olink Proteomics panels containing these DUX4 targets were also examined in secondary exploratory analysis. Placental alkaline phosphatase (ALPP) levels correlated with DUX4 expression in both cell-based FSHD systems but did not distinguish FSHD patient serum from unaffected controls. ALPP, as measured with the Olink Proteomics platform, is not a promising FSHD serum biomarker candidate but could be utilized to evaluate DUX4 activity in discovery research efforts.

The Dutch registry for facioscapulohumeral muscular dystrophy: Cohort profile and longitudinal patient reported outcomes

Facioscapulohumeral dystrophy (FSHD) is the second most prevalent inherited muscular disorder and currently lacks a pharmaceutical treatment. The Dutch FSHD Registry was initiated in 2015 as a result of an international collaboration on trial readiness. This paper presents the cohort profile and six years of follow-up data of the registered FSHD patients. At the time of self-registration and every six months thereafter, participants were invited to complete a digital survey of patient and disease characteristics and the Dutch versions of the Checklist Individual Strength (CIS20R), the Individualised Neuromuscular Quality of Life Questionnaire (INQoL), the Beck Depression Index – Primary Care and the McGill Pain Questionnaire. From March 2015 to March 2021, 373 participants completed at least one survey. At baseline, fatigue and muscle weakness were the most frequently reported symptoms (median CIS20R sumscore 77 [IQR 60-92], median INQoL Fatigue score 58 [IQR 42-68] and median INQoL weakness score 58 [IQR 42-68]). Pain was experienced most often in the head and shoulder region (193, 52%). Nineteen of the 23 (sub)sections of questionnaires showed no significant changes over time. We conclude that the Dutch FSHD Registry was successfully set up, enabling collection of longitudinal data and facilitating recruitment in several studies.

Establishing the role of muscle ultrasound as an imaging biomarker in facioscapulohumeral muscular dystrophy

Facioscapulohumeral muscular dystrophy (FSHD) is a hereditary muscle disease, that causes weakness and wasting of skeletal muscles. In this cross-sectional cohort-study on FSHD patients, we assessed muscle ultrasound findings and their relation to clinical outcome measures, evaluating the role of ultrasound as biomarker in FSHD. We included 115 genetically confirmed FSHD patients (52% males, age-range 22–80 years). They were subjected to a standardized muscle ultrasound protocol of seven truncal and upper- and lower extremity muscles bilaterally. Muscle images were scored using the Heckmatt scale. Muscle echogenicity was quantified using z-scores. Compound echogenicity and Heckmatt scores were calculated. Nearly all patients (94%) had one or multiple muscles with an increased echogenicity z-score. The trapezius muscle was most severely affected, followed by the rectus femoris muscle. Both compound ultrasound scores strongly with multiple clinical outcome measures (ρ 0.68–0.79, p < 0.001). While most muscles showed a high level of agreement between the echogenicity z-score and Heckmatt score (>95%), the tibialis anterior and gastrocnemius muscle showed lower levels of agreement (82 and 92%). In conclusion, our study confirms the use of muscle ultrasound as clinical severity biomarker and provides a solid base for future longitudinal studies to establish ultrasound as a monitoring biomarker in FSHD.

FSHD muscle shows perturbation in fibroadipogenic progenitor cells, mitochondrial function and alternative splicing independently of inflammation.

Facioscapulohumeral muscular dystrophy (FSHD) is a prevalent, incurable myopathy. FSHD is highly heterogeneous, with patients following a variety of clinical trajectories, complicating clinical trials. Skeletal muscle in FSHD undergoes fibrosis and fatty replacement that can be accelerated by inflammation, adding to heterogeneity. Well controlled molecular studies are thus essential to both categorize FSHD patients into distinct subtypes and understand pathomechanisms. Here, we further analyzed RNA-sequencing data from 24 FSHD patients, each of whom donated a biopsy from both a non-inflamed (TIRM-) and inflamed (TIRM+) muscle, and 15 FSHD patients who donated peripheral blood mononucleated cells (PBMCs), alongside non-affected control individuals. Differential gene expression analysis identified suppression of mitochondrial biogenesis and up-regulation of fibroadipogenic progenitor (FAP) gene expression in FSHD muscle, which was particularly marked on inflamed samples. PBMCs demonstrated suppression of antigen presentation in FSHD. Gene expression deconvolution revealed FAP expansion as a consistent feature of FSHD muscle, via meta-analysis of 7 independent transcriptomic datasets. Clustering of muscle biopsies separated patients in an unbiased manner into clinically mild and severe subtypes, independently of known disease modifiers (age, sex, D4Z4 repeat length). Lastly, the first genome-wide analysis of alternative splicing in FSHD muscle revealed perturbation of autophagy, BMP2 and HMGB1 signalling. Overall, our findings reveal molecular subtypes of FSHD with clinical relevance and identify novel pathomechanisms for this highly heterogeneous condition.

Muscle fibrosis as a prognostic biomarker in facioscapulohumeral muscular dystrophy: a retrospective cohort study

Facioscapulohumeral muscular dystrophy (FSHD) is an autosomal dominant epigenetic disorder with highly variable muscle involvement and disease progression. Ongoing clinical trials, aimed at counteracting muscle degeneration and disease progression in FSHD patients, increase the need for reliable biomarkers. Muscle magnetic resonance imaging (MRI) studies showed that the appearance of STIR-positive (STIR+) lesions in FSHD muscles represents an initial stage of muscle damage, preceding irreversible adipose changes. Our study aimed to investigate fibrosis, a parameter of muscle degeneration undetectable by MRI, in relation to disease activity and progression of FSHD muscles. We histologically evaluated collagen in FSHD1 patients’ (STIR+ n = 27, STIR− n = 28) and healthy volunteers’ (n = 12) muscles by picrosirius red staining. All patients (n = 55) performed muscle MRI before biopsy, 45 patients also after 1 year and 36 patients also after 2 years. Fat content (T1 signal) and oedema/inflammation (STIR signal) were evaluated at baseline and at 1- and 2-year MRI follow-up. STIR+ muscles showed significantly higher collagen compared to both STIR− (p = 0.001) and healthy muscles (p < 0.0001). STIR− muscles showed a higher collagen content compared to healthy muscles (p = 0.0194). FSHD muscles with a worsening in fatty infiltration during 1- (P = 0.007) and 2-year (P < 0.0001) MRI follow-up showed a collagen content of 3.6- and 3.7-fold higher compared to FSHD muscles with no sign of progression. Moreover, the fibrosis was significantly higher in STIR+ muscles who showed a worsening in fatty infiltration in a timeframe of 2 years compared to both STIR− (P = 0.0006) and STIR+ muscles with no sign of progression (P = 0.02). Fibrosis is a sign of muscle degeneration undetectable at MRI never deeply investigated in FSHD patients. Our data show that 23/27 of STIR+ and 12/28 STIR− muscles have a higher amount of collagen deposition compared to healthy muscles. Fibrosis is higher in FSHD muscles with a worsening in fatty infiltration thus suggesting that its evaluation with innovative non-invasive techniques could be a candidate prognostic biomarker for FSHD, to be used to stratify patients and to evaluate the efficacy of therapeutic treatments.

P202 The UK Facioscapulohumeral Muscular Dystrophy Patient Registry: a powerful tool to support clinical research and patient voice in the translational research pathway

P202 The UK Facioscapulohumeral Muscular Dystrophy Patient Registry: a powerful tool to support clinical research and patient voice in the translational research pathway

Face to Face: deciphering facial involvement in inclusion body myositis.

The objective of this study is to evaluate the frequency and characteristics of facial involvement in inclusion body myositis (IBM) patients and to compare it to the one previously described in facioscapulohumeral dystrophy (FSHD) patients. Thirty-two IBM patients were included and compared to 29 controls and 39 FSHD patients. All participants were recorded in a video as they performed a series of seven facial tasks. Five raters independently assessed facial weakness using both a qualitative evaluation and a semi-quantitative facial weakness score (FWS). IBM patients had higher FWS than controls (7.89 ± 7.56 vs 1.06 ± 0.88, p < 0.001). Twenty IBM patients (63%) had a facial weakness with a FWS above the maximum value for controls. All facial tasks were significantly more impaired in IBM patients compared to controls (p < 0.001), task 2 evaluating orbiculari oculi muscle weakness being the most affected. IBM patients with facial weakness reported more swallowing troubles than IBM patients without facial weakness (p = 0.03). FSHD patients displayed higher FWS than IBM patients (12.16 ± 8.37 vs 7.89 ± 7.56, p = 0.01) with more pronounced facial asymmetry (p = 0.01). FWS inter-rater ICC was 0.775. This study enabled us to estimate the frequency of facial impairment in IBM in more than half of patients, to detail its characteristics and to compare them with those of FSHD patients. The standardized, semi-quantitative FWS is an interesting diagnostic help in IBM as it appeared more sensitive than qualitative evaluation to detect mild facial weakness.

Autosomal dominant in cis D4Z4 repeat array duplication alleles in facioscapulohumeral dystrophy.

Facioscapulohumeral dystrophy (FSHD) has a unique genetic aetiology resulting in partial chromatin relaxation of the D4Z4 macrosatellite repeat array on 4qter. This D4Z4 chromatin relaxation facilitates inappropriate expression of the transcription factor DUX4 in skeletal muscle. DUX4 is encoded by a retrogene that is embedded within the distal region of the D4Z4 repeat array. In the European population, the D4Z4 repeat array is usually organized in a single array that ranges between 8 and 100 units. D4Z4 chromatin relaxation and DUX4 derepression in FSHD is most often caused by repeat array contraction to 1-10 units (FSHD1) or by a digenic mechanism requiring pathogenic variants in a D4Z4 chromatin repressor like SMCHD1, combined with a repeat array between 8 and 20 units (FSHD2). With a prevalence of 1.5% in the European population, in cis duplications of the D4Z4 repeat array, where two adjacent D4Z4 arrays are interrupted by a spacer sequence, are relatively common but their relationship to FSHD is not well understood. In cis duplication alleles were shown to be pathogenic in FSHD2 patients; however, there is inconsistent evidence for the necessity of an SMCHD1 mutation for disease development. To explore the pathogenic nature of these alleles we compared in cis duplication alleles in FSHD patients with or without pathogenic SMCHD1 variant. For both groups we showed duplication-allele-specific DUX4 expression. We studied these alleles in detail using pulsed-field gel electrophoresis-based Southern blotting and molecular combing, emphasizing the challenges in the characterization of these rearrangements. Nanopore sequencing was instrumental to study the composition and methylation of the duplicated D4Z4 repeat arrays and to identify the breakpoints and the spacer sequence between the arrays. By comparing the composition of the D4Z4 repeat array of in cis duplication alleles in both groups, we found that specific combinations of proximal and distal repeat array sizes determine their pathogenicity. Supported by our algorithm to predict pathogenicity, diagnostic laboratories should now be furnished to accurately interpret these in cis D4Z4 repeat array duplications, alleles that can easily be missed in routine settings.

Antagonism among DUX family members evolved from an ancestral toxic single homeodomain protein

Double homeobox (DUX) genes are unique to eutherian mammals, expressed transiently during zygotic genome activation (ZGA) and involved in facioscapulohumeral muscular dystrophy (FSHD) and cancer when misexpressed. We evaluate the 3 human DUX genes and the ancestral single homeobox gene sDUX from the non-eutherian mammal, platypus, and find that DUX4 cytotoxicity is not shared with DUXA or DUXB, but surprisingly is shared with platypus sDUX, which binds DNA as a homodimer and activates numerous ZGA genes and long terminal repeat (LTR) elements. DUXA, although transcriptionally inactive, has DNA binding overlap with DUX4, and DUXA-VP64 activates DUX4 targets and is cytotoxic. DUXA competition antagonizes the activity of DUX4 on its target genes, including in FSHD patient cells. Since DUXA is a DUX4 target gene, this competition potentiates feedback inhibition, constraining the window of DUX4 activity. The DUX gene family therefore comprises antagonistic members of opposing function, with implications for their roles in ZGA, FSHD, and cancer.

Whole exome sequencing highlights rare variants in CTCF, DNMT1, DNMT3A, EZH2 and SUV39H1 as associated with FSHD.

Introduction: Despite the progress made in the study of Facioscapulohumeral Dystrophy (FSHD), the wide heterogeneity of disease complicates its diagnosis and the genotype-phenotype correlation among patients and within families. In this context, the present work employed Whole Exome Sequencing (WES) to investigate known and unknown genetic contributors that may be involved in FSHD and may represent potential disease modifiers, even in presence of a D4Z4 Reduced Allele (DRA). Methods: A cohort of 126 patients with clinical signs of FSHD were included in the study, which were characterized by D4Z4 sizing, methylation analysis and WES. Specific protocols were employed for D4Z4 sizing and methylation analysis, whereas the Illumina® Next-Seq 550 system was utilized for WES. The study included both patients with a DRA compatible with FSHD diagnosis and patients with longer D4Z4 alleles. In case of patients harboring relevant variants from WES, the molecular analysis was extended to the family members. Results: The WES data analysis highlighted 20 relevant variants, among which 14 were located in known genetic modifiers (SMCHD1, DNMT3B and LRIF1) and 6 in candidate genes (CTCF, DNMT1, DNMT3A, EZH2 and SUV39H1). Most of them were found together with a permissive short (4-7RU) or borderline/long DRA (8-20RU), supporting the possibility that different genes can contribute to disease heterogeneity in presence of a FSHD permissive background. The segregation and methylation analysis among family members, together with clinical findings, provided a more comprehensive picture of patients. Discussion: Our results support FSHD pathomechanism being complex with a multigenic contribution by several known (SMCHD1, DNMT3B, LRIF1) and possibly other candidate genes (CTCF, DNMT1, DNMT3A, EZH2, SUV39H1) to disease penetrance and expressivity. Our results further emphasize the importance of extending the analysis of molecular findings within the proband's family, with the purpose of providing a broader framework for understanding single cases and allowing finer genotype-phenotype correlations in FSHD-affected families.

A Systemically Administered Unconjugated Antisense Oligonucleotide Targeting DUX4 Improves Muscular Injury and Motor Function in FSHD Model Mice.

Facioscapulohumeral muscular dystrophy (FSHD), one of the most common muscular dystrophies, is caused by an abnormal expression of the DUX4 gene in skeletal muscles, resulting in muscle weakness. In this study, we investigated MT-DUX4-ASO, a novel gapmer antisense oligonucleotide (ASO). MT-DUX4-ASO decreased the expression of DUX4 and its target genes in FSHD patient-derived myoblasts. For the first time, we demonstrated that a systemically administered ASO, even without a ligand for drug delivery, could significantly improve muscle injury and motor function in the ACTA1-MCM/FLExDUX4 (DUX4-TG) mouse model of FSHD. Tamoxifen (TMX) injection transiently induces skeletal-muscle-specific DUX4 expression in DUX4-TG mice, while the skeletal muscles of TMX-untreated DUX4-TG mice have leaky DUX4 expression in a small subset of myofibers similar to those of FSHD patients. Subcutaneous 10 mg/kg of MT-DUX4-ASO at two-week intervals significantly suppressed muscular DUX4 target gene expression, histological muscle injury, and blood muscle injury marker elevation in TMX-untreated DUX4-TG mice. Notably, MT-DUX4-ASO at 10 mg/kg every other week significantly prevented the TMX-induced declines in treadmill test running speed and muscle force in DUX4-TG mice. Thus, the systemically administered unconjugated MT-DUX4-ASO suppressed disease progression in DUX4-TG mice, extending the potential of unconjugated ASOs as a promising FSHD treatment strategy.

The FSHD muscle-blood biomarker: a circulating transcriptomic biomarker for clinical severity in facioscapulohumeral muscular dystrophy.

Facioscapulohumeral muscular dystrophy (FSHD) is a prevalent, incurable skeletal myopathy. Clinical trials for FSHD are hindered by heterogeneous biomarkers poorly associated with clinical severity, requiring invasive muscle biopsy. Macroscopically, FSHD presents with slow fatty replacement of muscle, rapidly accelerated by inflammation. Mis-expression of the transcription factor DUX4 is currently accepted to underlie pathogenesis, and mechanisms including PAX7 target gene repression have been proposed. Here, we performed RNA-sequencing on MRI-guided inflamed and isogenic non-inflamed muscle biopsies from the same clinically characterized FSHD patients (n = 24), alongside isogenic peripheral blood mononucleated cells from a subset of patients (n = 13) and unaffected controls (n = 11). Multivariate models were employed to evaluate the clinical associations of five published FSHD transcriptomic biomarkers. We demonstrated that PAX7 target gene repression can discriminate control, inflamed and non-inflamed FSHD muscle independently of age and sex (P < 0.013), while the discriminatory power of DUX4 target genes was limited to distinguishing FSHD muscle from control. Importantly, the level of PAX7 target gene repression in non-inflamed muscle associated with clinical assessments of FSHD severity (P = 0.04). DUX4 target gene biomarkers in FSHD muscle showed associations with lower limb fat fraction and D4Z4 array length but not clinical assessment. Lastly, PAX7 target gene repression in FSHD muscle correlated with the level in isogenic peripheral blood mononucleated cells (P = 0.002). A refined PAX7 target gene biomarker comprising 143/601 PAX7 target genes computed in peripheral blood (the FSHD muscle-blood biomarker) associated with clinical severity in FSHD patients (P < 0.036). Our new circulating biomarker validates as a classifier of clinical severity in an independent data set of 54 FSHD patient and 29 matched control blood samples, with improved power in older patients (P = 0.03). In summary, we present the minimally invasive FSHD muscle-blood biomarker of FSHD clinical severity valid in patient muscle and blood, of potential use in routine disease monitoring and clinical trials.

The upper extremity functional index (UEFI): Italian validation in patients with Facioscapulohumeral muscular dystrophy

Purpose The aim of this study was to adapt the Upper Extremity Functional Index (UEFI) to an Italian population affected by Facioscapulohumeral muscular dystrophy (FSHD) by translating and validating this instrument in an Italian cohort. Materials and methods Five Italian FSHD patients were interviewed regarding the form and content of the translated instrument. Subsequently, fifty-two patients were recruited for the validation purpose by serially completing the UEFI-IT and a battery of clinical assessments and questionnaires. Finally, a subset of thirty-nine patients underwent test-retest reliability. Results The Italian translation of the UEFI was highly relevant to patients, had a level of test-retest reliability from “good” to “excellent” (ICC = 0.90 with 95% confidence interval between 0.82 and 0.95), and a satisfactory internal consistency (Cronbach’s alpha = 0.96). Participants confirmed the usefulness and clearness of the tool in cultural validity. In known group validity, the UEFI-IT was significantly lower in patients unable to walk (24.10 ± 11.33 vs 55.71 ± 13.98, p < .0001; AUC = 0.9631) and in patients with longer disease duration (43.43 ± 17.16 vs 58.14 ± 13.71, p = 0.0034; AUC = 0.7359). Finally, the concurrent validity showed strong associations between the UEFI-IT and motor assessments, pain perception, and quality-of-life evaluations. Conclusions Overall, the UEFI-IT is an appropriate, valid, and reliable outcome measure for Italian-speaking FSHD patients.

Five-year follow-up study on quantitative muscle magnetic resonance imaging in facioscapulohumeral muscular dystrophy: The link to clinical outcome.

It is unclear how changes in quantitative muscle magnetic resonance imaging (MRI) relate to changes in clinical outcome in facioscapulohumeral muscular dystrophy (FSHD), although this information is crucial for optimal use of MRI as imaging biomarker in trials. We therefore assessed muscle MRI and clinical outcome measures in a large longitudinal prospective cohort study. All patients were assessed by MRI at baseline and at 5-year follow-up, employing 2pt-Dixon and turbo inversion recovery magnitude (TIRM) sequences, after which fat fraction and TIRM positivity of 19 leg muscles were determined bilaterally. The MRI compound score (CoS) was defined as the mean fat fraction of all muscles weighted for cross-sectional area. Clinical outcome measures included the Ricci-score, FSHD clinical score (FSHD-CS), MRC sumscore (MRC-SS), and motor-function-measure (MFM). We included 105 FSHD patients [mean age 54±14years, median Ricci-score 7 (range 0-10)]. The median change over 5years' time in the MRI-CoS was 2.0% (range -4.6 to +12.1; P<0.001). The median change over 5years' time in clinical outcome measures was small in all measures, with z-scores ranging from 5.0 to 7.2 (P<0.001). The change in MRI-CoS correlated with change in FSHD-CS and Ricci-score (ρ=0.25, respectively; ρ=0.23, P<0.05). The largest median increase in MRI-CoS was seen in baseline subgroups with an MRI-CoS 20-40% (6.1%), with ≥2 TIRM positive muscles (3.5%) or with an FSHD-CS 5-10 (3.1%). This 5-year study showed significant changes in MRI and clinical outcome measures and a significant correlation between changes in MRI-CoS and changes in clinical outcome measures. In addition, we identified subgroups of patients that are most prone to radiological disease progression. This knowledge further establishes quantitative MRI parameters as prognostic biomarkers in FSHD and as efficacy biomarkers in upcoming clinical trials.

Shoulder injuries in Facioscapulohumeral muscular dystrophy patients (P6-8.001)

<h3>Objective:</h3> To describe the types, prevalence, and history of shoulder injuries in patients with facioscapulohumeral muscular dystrophy (FSHD). <h3>Background:</h3> FSHD is a dominantly inherited, slowly progressive muscular dystrophy with variable clinical manifestations. It usually initially presents as weakness in the face, shoulder, and upper extremities, eventually extending to the lower body. MRI studies have shown that wasting in the shoulder tends to follow a muscle-specific pattern, but to date there are no studies investigating shoulder injuries as an outcome, nor their impact on patients. <h3>Design/Methods:</h3> We distributed a cross-sectional anonymous web-administered survey of adult FSHD patients identified through the US National FSHD Registry and the FSHD Society registry. The survey collected FSHD history, functional status, severity scores, and detailed history of shoulder injury (defined as “any shoulder condition that caused pain, stiffness, or dysfunction in addition to that from FSHD”). <h3>Results:</h3> We identified 613 FSHD patients ranging from 18 to 91 years old (M=56.4, SD=14.7). Average age of symptom onset and diagnosis were 24 and 35, respectively, with an average Brooke Upper Extremity Score of 2.7 (SD=1.03). 89% of patients reported current shoulder weakness, while 34% reported a history of shoulder injury. The most-reported injuries were rotator cuff tendinitis/tendinopathy and rotator cuff tear, both with a prevalence of 9.8% – followed by subacromial bursitis (7.1%), shoulder impingement (6.0%), and dislocated shoulder (5.0%). Of the patients who reported a history of at least one shoulder injury: 42% believed that FSHD was entirely to blame, and 49% rated the impact of their injury on their life – at its worst – at 8/10 or higher. <h3>Conclusions:</h3> By exploring the previously undescribed burden of shoulder injuries in the FSHD patient population, this study may improve patients’ understanding of their condition and inform clinicians’ approach to monitoring the disorder. <b>Disclosure:</b> Mr. Liu has nothing to disclose. Dr. Tawil has received personal compensation in the range of $500-$4,999 for serving as a Consultant for DYNE Therapeutics. Dr. Tawil has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Arrowhead Pharma. Dr. Tawil has received personal compensation in the range of $5,000-$9,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Fulcrum Therapeutics. Dr. Tawil has received personal compensation in the range of $500-$4,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Acceleron Pharma. Dr. Tawil has received personal compensation in the range of $500-$4,999 for serving on a Scientific Advisory or Data Safety Monitoring board for MT Pharma. Dr. Tawil has received personal compensation in the range of $500-$4,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Roche Pharma. Dr. Tawil has received personal compensation in the range of $500-$4,999 for serving on a Scientific Advisory or Data Safety Monitoring board for miRecule. The institution of Dr. Tawil has received research support from Friends of FSH Research. The institution of Dr. Tawil has received research support from FSH Society. The institution of Dr. Tawil has received research support from NIH. The institution of Dr. Tawil has received research support from Fulcrum. Dr. Tawil has received intellectual property interests from a discovery or technology relating to health care. Dr. Tawil has received publishing royalties from a publication relating to health care. Dr. Statland has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Arrowhead. Dr. Statland has received personal compensation in the range of $500-$4,999 for serving as a Consultant for ML Bio. Dr. Statland has received personal compensation in the range of $500-$4,999 for serving as a Consultant for MT Pharma. Dr. Statland has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Epic Bio. Dr. Statland has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Armatus . Dr. Statland has received personal compensation in the range of $10,000-$49,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Dyne Therapeutics. Dr. Statland has received personal compensation in the range of $500-$4,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Avidity . Dr. Statland has received personal compensation in the range of $5,000-$9,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Fulcrum Therapeutics. Dr. Statland has received personal compensation in the range of $5,000-$9,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Roche. The institution of Dr. Statland has received research support from NIH. The institution of Dr. Statland has received research support from FSHD Society. The institution of Dr. Statland has received research support from Friends of FSH Research. The institution of Dr. Statland has received research support from FSHD Canada. The institution of Dr. Statland has received research support from MDA.

Feasibility of Measuring Functional Performance of FSHD Patients Using Wearable Sensors to Quantify Physical Activity (S7.006)

<h3>Objective:</h3> Evaluate feasibility to monitor daily activity and assess functional outcomes using wearable sensor devices in an open label study (OLS) of losmapimod in facioscapulohumeral muscular dystrophy (FSHD). <h3>Background:</h3> Evaluation of clinical outcome assessments in FSHD is challenging due to the variable onset, severity, and progression. Fulcrum is evaluating the safety and efficacy of losmapimod for the treatment of FSHD with selected clinical outcome assessments in the ongoing OLS. Assessment with wearables may be a sensitive measure of upper extremity function, activities of daily living, and mobility in FSHD. <h3>Design/Methods:</h3> ActiMyo wearable activity monitoring devices were provided to participants in the OLS to be placed on 1 wrist and on 1 ankle. Activity was monitored during the day in the outpatient setting intermittently; alternating two weeks on and two weeks off until the end of the study. An 8-week baselining period was collected, with similar wear frequency, prior to initiating treatment. Participants performed prescribed movements of upper and lower extremities twice daily. <h3>Results:</h3> Fourteen subjects, ages 18 to 65 years with genetically confirmed FSHD1 and clinical severity score of 2 to 4 (range 0–5), received 15 mg losmapimod twice daily and completed the study over 60 weeks. Compliance for wearing the devices was 99%. All 14 participants were monitored for a total of 2941 days or 36758 hours, for an average of 2626 hours per participant. Multiple parameters calculated from the upper and lower extremities were found to be reliable (ICC &gt; 0.90). Analysis of correlations with clinical outcome assessments will be reported. <h3>Conclusions:</h3> Measurement of functional performance in FSHD patients using wearable sensors is feasible, reliable, and correlates with multiple clinical outcome assessments, activities of daily living, and mobility. This assessment could provide critical data about disease progression and treatment efficacy in future clinical trials. <b>Disclosure:</b> The institution of Mr. Kools has received research support from Fulcrum Therapeutics. The institution of Mrs. Voermans has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Dynacure. The institution of Mrs. Voermans has received personal compensation in the range of $0-$499 for serving on a Scientific Advisory or Data Safety Monitoring board for NIH. The institution of Mrs. Voermans has received personal compensation in the range of $500-$4,999 for serving as an Editor, Associate Editor, or Editorial Advisory Board Member for Neuromuscular disorder. The institution of Karlien Mul has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Avidity Biosciences. Dr. Jiang has received personal compensation for serving as an employee of Fulcrum Therapeutics. Dr. Shoskes has received personal compensation for serving as an employee of Fulcrum Therapeutics. An immediate family member of Dr. Shoskes has received personal compensation for serving as an employee of Exact Science. Ms. Marshall has nothing to disclose. Dr. Tarachandani has received personal compensation for serving as an employee of UsinLife LLC. Dr. Figueredo has received personal compensation in the range of $500-$4,999 for serving as a Consultant for UsinLife LLC. Mr. Eggenspieler has received personal compensation in the range of $50,000-$99,999 for serving as a Healthcare director with Sysnav.