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BackgroundPatients with neuromuscular disease (NMD) have progressive muscle weakness and limited mobility that contributes to a sedentary lifestyle. A sedentary lifestyle often leads to deconditioning and decreases cardiorespiratory fitness (CRF). Cardiopulmonary exercise testing (CPX) is the gold standard for the evaluation of CRF but has not been widely applied in patients with NMD.MethodsPatients with NMD were recruited from the Neuromuscular Clinic at the Stanford Neurosciences Health Center at Stanford University. Matched controls were recruited by staff from the local community by word of mouth. All participants performed CPX using a wheelchair-accessible total body trainer and a wearable metabolic cart system to volitional exhaustion.ResultsParticipants with NMD and limited mobility (n = 37) were able to perform high-quality CPX with no adverse events or safety concerns of comparable quality to controls. Average respiratory exchange ratio for NMD patients was 1.08 ± 0.16, and average rating of perceived exertion was 18 ± 2 compared with 1.16 ± 0.12 and 18 ± 2 for controls, respectively (P = 0.17 and P = 0.78, respectively). Patients with NMD on average showed markedly reduced percent predicted VO2max and impaired ventilatory efficiency.ConclusionHigh-quality CPX in patients with NMD may reveal distinct physiological profiles that may lead to a better understanding of pathology in these individuals. CPX on total body trainers may be a viable method for improving exercise prescription for patients with NMD.

Myotonic dystrophy type 1 (DM1) is known to affect cognitive function, but the best methods to assess central nervous system involvement in multicenter studies have not been determined. In this study our primary aim was to evaluate the potential of computerized cognitive tests to assess cognition in DM1.We conducted a prospective, longitudinal, observational study of 113 adults with DM1 at six sites. Psychomotor speed, attention, working memory, and executive functioning were assessed at baseline, 3 months, and 12 months using computerized cognitive tests. Results were compared with assessments of muscle function and patient reported outcomes (PROs), including the Myotonic Dystrophy Health Index (MDHI) and the 5-dimension EuroQol (EQ-5D-5L) questionnaire.Based on intraclass correlation coefficients, computerized cognitive tests had moderate to good reliability for psychomotor speed (0.76), attention (0.82), working memory speed (0.79), working memory accuracy (0.65), and executive functioning (0.87). Performance at baseline was lowest for working memory accuracy (P .0001). Executive function performance improved from baseline to 3 months (P .0001), without further changes over 1 year. There was a moderate correlation between poorer executive function and larger CTG repeat size (r = -0.433). There were some weak associations between PROs and cognitive performance.Computerized tests of cognition are feasible in multicenter studies of DM1. Poor performance was exhibited in working memory, which may be a useful variable in clinical trials. Learning effects may have contributed to the improvement in executive functioning. The relationship between PROs and cognitive impairment in DM1 requires further study.

Background: Adult patients with adrenoleukodystrophy have a poor prognosis owing to development of adrenomyeloneuropathy. Additionally, a large proportion of patients with adrenomyeloneuropathy develop life-threatening progressive cerebral adrenoleukodystrophy. Leriglitazone is a novel selective peroxisome proliferator-activated receptor gamma agonist that regulates expression of key genes that contribute to neuroinflammatory and neurodegenerative processes implicated in adrenoleukodystrophy disease progression. We aimed to assess the effect of leriglitazone on clinical, imaging, and biochemical markers of disease progression in adults with adrenomyeloneuropathy. Methods: ADVANCE was a 96-week, randomised, double-blind, placebo-controlled, phase 2–3 trial done at ten hospitals in France, Germany, Hungary, Italy, the Netherlands, Spain, the UK, and the USA. Ambulatory men aged 18–65 years with adrenomyeloneuropathy without gadolinium enhancing lesions suggestive of progressive cerebral adrenoleukodystrophy were randomly assigned (2:1 without stratification) to receive daily oral suspensions of leriglitazone (150 mg starting dose; between baseline and week 12, doses were increased or decreased to achieve plasma concentrations of 200 μg·h/mL [SD 20%]) or placebo by means of an interactive response system and a computer-generated sequence. Investigators and patients were masked to group assignment. The primary efficacy endpoint was change from baseline in the Six-Minute Walk Test distance at week 96, analysed in the full-analysis set by means of a mixed model for repeated measures with restricted maximum likelihood and baseline value as a covariate. Adverse events were also assessed in the full-analysis set. This study was registered with ClinicalTrials.gov, NCT03231878; the primary study is complete; patients had the option to continue treatment in an open-label extension, which is ongoing. Findings: Between Dec 8, 2017, and Oct 16, 2018, of 136 patients screened, 116 were randomly assigned; 62 [81%] of 77 patients receiving leriglitazone and 34 [87%] of 39 receiving placebo completed treatment. There was no between-group difference in the primary endpoint (mean [SD] change from baseline leriglitazone: –27·7 [41·4] m; placebo: –30·3 [60·5] m; least-squares mean difference –1·2 m; 95% CI –22·6 to 20·2; p=0·91). The most common treatment emergent adverse events in both the leriglitazone and placebo groups were weight gain (54 [70%] of 77 vs nine [23%] of 39 patients, respectively) and peripheral oedema (49 [64%] of 77 vs seven [18%] of 39). There were no deaths. Serious treatment-emergent adverse events occurred in 14 (18%) of 77 patients receiving leriglitazone and ten (26%) of 39 patients receiving placebo. The most common serious treatment emergent adverse event, clinically progressive cerebral adrenoleukodystrophy, occurred in six [5%] of 116 patients, all of whom were in the placebo group. Interpretation: The primary endpoint was not met, but leriglitazone was generally well tolerated and rates of adverse events were in line with the expected safety profile for this drug class. The finding that cerebral adrenoleukodystrophy, a life-threatening event for patients with adrenomyeloneuropathy, occurred only in patients in the placebo group supports further investigation of whether leriglitazone might slow the progression of cerebral adrenoleukodystrophy. Funding: Minoryx Therapeutics.

Purpose The NIH Undiagnosed Diseases Network (UDN) evaluates participants with disorders that have defied diagnosis, applying personalized clinical and genomic evaluations and innovative research. The clinical sites of the UDN are essential to advancing the UDN mission; this study assesses their contributions relative to standard clinical practices. Methods We analyzed retrospective data from four UDN clinical sites, from July 2015 to September 2019, for diagnoses, new disease gene discoveries and the underlying investigative methods. Results Of 791 evaluated individuals, 231 received 240 diagnoses and 17 new disease-gene associations were recognized. Straightforward diagnoses on UDN exome and genome sequencing occurred in 35% (84/240). We considered these tractable in standard clinical practice, although genome sequencing is not yet widely available clinically. The majority (156/240, 65%) required additional UDN-driven investigations, including 90 diagnoses that occurred after prior nondiagnostic exome sequencing and 45 diagnoses (19%) that were nongenetic. The UDN-driven investigations included complementary/supplementary phenotyping, innovative analyses of genomic variants, and collaborative science for functional assays and animal modeling. Conclusion Investigations driven by the clinical sites identified diagnostic and research paradigms that surpass standard diagnostic processes. The new diagnoses, disease gene discoveries, and delineation of novel disorders represent a model for genomic medicine and science.

Aim: Compare efficacies of deflazacort and prednisone/prednisolone in providing clinically meaningful delays in loss of physical milestones in patients with nonsense mutation Duchenne muscular dystrophy. Materials & methods: Placebo data from Phase IIb (ClinicalTrials.gov Identifier: NCT00592553) and ACT DMD (ClinicalTrials.gov Identifier: NCT01826487) ataluren nonsense mutation Duchenne muscular dystrophy clinical trials were retrospectively combined in meta-analyses (intent-to-treat population; for change from baseline to week 48 in 6-min walk distance [6MWD] and timed function tests). Results: Significant improvements in change in 6-min walk distance with deflazacort versus prednisone/prednisolone (least-squares mean difference 39.54 m [95% CI: 13.799, 65.286; p = 0.0026]). Significant and clinically meaningful improvements in 4-stair climb and 4-stair descend for deflazacort versus prednisone/prednisolone. Conclusion: Deflazacort provides clinically meaningful delays in loss of physical milestones over 48 weeks compared with prednisone/prednisolone for patients with nonsense mutation Duchenne muscular dystrophy.

BACKGROUND Standard of care for patients with neuromuscular disease (NMD) includes exercise testing and exercise therapy. The focus of exercise in this group is to respond to muscular skeletal pathologies related to NMD, improve general health and fitness and health related quality of life. Cardiopulmonary exercise testing CPX is the gold standard for assessing cardiorespiratory fitness, but the use of CPX has been limited in NMD, especially for those patients with low mobility. We present our data on peak CPX and submaximal A6MCT exercise testing in patients with NMD and limited mobility. METHODS We prospectively recruited and consented consecutive patients who were performing outpatient physical therapy at the Neuromuscular Clinic at Stanford University Hospital. Patients performed CPX to volitional exhaustion on a total body trainer and/ or A6MCT at highest pace possible for six minutes on an ergometer. Respiratory gas data were collected on a breath-by-breath basis and analyzed after applying a rolling 30 second average filter. Collected data were compared and contrasted between CPX and A6MCT and compared to normative data and controls. RESULTS There were no complications or adverse events during the study, and data quality was adequate for CPX and A6MCT and comparable to controls. Average respiratory exchange ratio (RER) for patients with NMD was 1.08±0.16 and average rating of perceived exertion (RPE) was 18.4±2.1 compared to 1.16±0.12 and 18.1±2.0 for controls. NMD patients on average showed markedly reduced percent predicted VO2 max (55.6±24.9 percent predicted) and impaired ventilatory efficiency. CONCLUSIONS Quality exercise testing is possible and worthwhile in patients with NMD and low mobility. Especially CPX may offer strong and standard assessment of CRF which may provide valuable clinical data both specific to NMD and nonspecific to improve outcomes. Although a commonly performed procedure, A6MCT would need more study to illustrate its utility for patients with NMD.

We present for the first time the generation of induced pluripotent stem cells (iPSCs) from a patient with a connexin-linked disease. The importance of gap junctional intercellular communication in bone homeostasis is exemplified by the autosomal dominant developmental disorder oculodentodigital dysplasia (ODDD), which is linked to mutations in the GJA1 (Cx43) gene. ODDD is characterized by craniofacial malformations, ophthalmic deficits, enamel hypoplasia, and syndactyly. In addition to harboring a Cx43 p.V216L mutation, ODDD iPSCs exhibit reduced Cx43 mRNA and protein abundance when compared to control iPSCs and display impaired channel function. Osteogenic differentiation involved an early, and dramatic downregulation of Cx43 followed by a slight upregulation during the final stages of differentiation. Interestingly, osteoblast differentiation was delayed in ODDD iPSCs. Moreover, Cx43 subcellular localization was altered during chondrogenic differentiation of ODDD iPSCs compared to controls and this may have contributed to the more compact cartilage pellet morphology found in differentiated ODDD iPSCs. These studies highlight the importance of Cx43 expression and function during osteoblast and chondrocyte differentiation, and establish a potential mechanism for how ODDD-associated Cx43 mutations may have altered cell lineages involved in bone and cartilage development. © 2017 American Society for Bone and Mineral Research.