Duchenne Muscular Dystrophy Research Articles

Duchenne Muscular Dystrophy-Associated Neurobehavioral Difficulties: Insights from Clinical Practice.

Emerging evidence underscores the high prevalence of neurobehavioral difficulties like ADHD, ASD and OCD, in patients with Duchenne muscular dystrophy (DMD). The substantial impact of these complex behavioral challenges in addition to motor function decline on the well-being of affected individuals and their families is increasingly evident. However, a uniform approach for effective screening, assessment and management of the neurobehavioral symptoms remains elusive. We explored strategies used by healthcare professionals with clinical expertise in DMD to address neurobehavioral symptoms, in order to uncover diverse practices and to identify potential directions for clinical approaches in managing DMD neurobehavioral symptoms. Twenty-eight respondents from 16 different countries completed an online survey. Only 35% of the centers systematically screened for neurobehavioral difficulties in their DMD population. Predominant screening methods included history taking and clinical observation. Common neurobehavioral difficulties encompassed learning challenges, dependency from adults, anxiety, concentration difficulties, and social deficits. The participating centers frequently employed parental counseling and liaison with psychosocial healthcare professionals for psychosocial intervention. This study underscores the complex behavioral landscape in DMD, highlighting the need for validated screening, assessment and management strategies and collaborative efforts in implementing these. We advocate for international consensus recommendations for screening, assessment and management of neurobehavioral difficulties in DMD to enhance patient care and communication across healthcare settings.

Development and Pilot Validation of the DuMAND Checklist to Screen for Duchenne Muscular Dystrophy-Associated Neurobehavioral Difficulties (DuMAND).

Patients with Duchenne muscular dystrophy (DMD) face a higher risk of neurobehavioral problems, yet an international consensus on screening, assessing, and managing these difficulties is lacking. This report introduces the term Duchenne Muscular Dystrophy-Associated Neurobehavioral Difficulties (DuMAND) to comprehensively cover the spectrum of neurobehavioral issues in DMD patients, including behavior, psychiatric disorders, and various cognitive, academic, and psychosocial deficits. To facilitate screening, the DuMAND Checklist, a 43-item tool with five subscales, was developed. DuMAND categories were derived through literature review, parent (48 mothers and 37 fathers), and expert (n = 28) input and feedback. The DuMAND Checklist subscales were developed iteratively, incorporating item selection, expert panel (n = 10) assessment for face validity, comprehensiveness, and a pilot validation study in a DMD sample (n = 20). DuMAND encompasses five categories: cognition and learning, social responsiveness, emotion regulation, externalizing behavior, and eating and sleeping. Preliminary validation of the DuMAND Checklist indicates acceptable-to-excellent internal consistency and construct validity. By introducing the DuMAND concept, this study seeks to inspire a consensus approach for screening, assessing, and managing neurobehavioral issues in DMD. Incorporating screening, using the DuMAND Checklist, in addition to medical follow-up will facilitate early intervention, addressing a critical gap in identification of neurobehavioral disorders in DMD. Future research is needed to further evaluate psychometric properties of the DuMAND Checklist and investigate the natural course of DuMAND.

Relationship Between Hand Strength and Function in Duchenne Muscular Dystrophy and Spinal Muscular Atrophy: Implications for Clinical Trials.

Measurement of muscle strength and motor function is recommended in clinical trials of neuromuscular diseases, but the loss of hand strength at which motor function is impacted is not documented. To establish the relationship between hand strength and function, and to determine the strength threshold that differentiates normal and abnormal hand function in individuals with Duchenne Muscular Dystrophy (DMD) or Spinal Muscular Atrophy (SMA). Maximal handgrip and key pinch strength were measured with the MyoGrip and MyoPinch dynamometers, respectively. Hand function was assessed using the MoviPlate, the Motor Function Measure items for distal upper limb (MFM-D3-UL) and the Cochin Hand Function Scale (CHFS). Data from 168 participants (91 DMD and 77 SMA, age 6-31 years) were analyzed. Relationships between strength and function were significant (P < 0.001). Hand function was generally preserved when strength was above the strength threshold determined by Receiver-Operating Characteristic (ROC) analysis: For MFM-D3-UL, the calculated handgrip strength thresholds were 41 and 13% of the predicted strength for a healthy subject (% pred) and the key pinch strength thresholds were 42 and 26% pred for DMD and SMA, respectively. For the MoviPlate, handgrip strength thresholds were 11 and 8% pred and key pinch strength thresholds were 21 and 11% pred for DMD and SMA, respectively. For participants with sub-threshold strength, hand function scores decreased with decreasing strength. At equal % pred strength, individuals with SMA had better functional scores than those with DMD. Hand function is strength-dependent for most motor tasks. It declines only when strength falls below a disease-specific threshold. Therefore, therapies capable of maintaining strength above this threshold should preserve hand function.

A case study of Duchenne muscular dystrophy caused by Alu element insertion in DMD gene and analysis of its gray-hair symptoms.

Duchenne muscular dystrophy (DMD) is a severe X-linked recessive genetic disorder caused by mutations in the DMD gene, which leads to a deficiency of the dystrophin protein. The main mutation types of this gene include exon deletions and duplications, point mutations, and insertions. These mutations disrupt the normal expression of dystrophin, ultimately leading to the disease. In this study, we reported a case of DMD caused by an insertion mutation in exon 59 (E59) of the DMD gene. The affected child exhibited significant abnormalities in related biochemical markers, early symptoms of DMD, and multiple gray hair. His mother and sister were carriers with slightly abnormal biochemical markers. The mother had mild clinical symptoms, while the sister had no clinical symptoms. Other family members were genetically and physically normal. Sequencing and sequence alignment revealed that the inserted fragment was an Alu element from the AluYa5 subfamily. This insertion produced two stop codons and a polyadenylate (polyA) tail. To understand the impact of this insertion on the DMD gene and its association with clinical symptoms, exonic splicing enhancer (ESE) prediction indicated that the insertion did not affect the splicing of E59. Therefore, we speculated that the insertion sequence would be present in the mRNA sequence of the DMD gene. The two stop codons and polyA tail likely terminate translation, preventing the production of functional dystrophin protein, which may be the mechanism leading to DMD. In addition to typical DMD symptoms, the child also exhibited premature graying of hair. This study reports, for the first time, a case of DMD caused by the insertion of an Alu element into the coding region of the DMD gene. This finding provides clues for studying gene mutations induced by Alu sequence insertion and expands the understanding of DMD gene mutations.

Quantifying the insurance value for rare diseases: Duchenne muscular dystrophy.

To quantify the magnitude of an ISPOR novel value element, insurance value, as applied to new treatments for a rare, severe disease with pediatric onset: Duchenne muscular dystrophy (DMD). Prospective survey of individuals planning to have children in the future. A survey was administered to US adults (aged ≥ 21 years) planning to have a child in the future to elicit willingness to pay (WTP) for insurance coverage for a new hypothetical DMD treatment that improved mortality and morbidity relative to the current standard of care. To identify an indifference point between status quo insurance and insurance with additional cost that would cover the treatment if respondents had a child with DMD, a multiple random staircase design was used. Insurance value-the value individuals receive from a reduction in future health risks-was calculated as the difference between respondent's WTP and what a risk-neutral individual would pay. The risk-neutral value was the product of the (1)probability of having a child with DMD (decision weighted), (2) quality-adjusted life-years (QALYs) gained from the new treatment, and (3) WTP per QALY. Among 207 respondents, 80.2% (n = 166) were aged 25 to 44 years, and 59.9% (n = 124) were women. WTP for insurance coverage of the hypothetical treatment was $973 annually, whereas the decision-weighted risk-neutral value was $452 per year. Thus, insurance value constituted 53.5% ($520) of value for new DMD treatments. Individuals planning to have children in the future are willing to pay more for insurance coverage of novel DMD treatments than is assumed under risk-neutral, QALY-based frameworks.

Givinostat: First Approval.

Givinostat (DUVYZAT™), an orally available histone deacetylase inhibitor, is being developed by Italfarmaco for the treatment of muscular dystrophy and polycythemia vera. Givinostat received its first approval on 21 March 2024, in the USA, for the treatment of Duchenne muscular dystrophy (DMD) in patients 6 years of age and older. Approval was based on the results of the multinational phase III EPIDYS trial, in which givinostat recipients showed less decline than placebo recipients in the time taken to perform a functional task. Givinostat represents the first nonsteroidal treatment for DMD to be approved for use in patients irrespective of the specific genetic variant underlying their disease. Givinostat is available as an oral suspension to be administered twice daily with food. The recommended dosage is based on the body weight of the patient. In the EU, regulatory review of givinostat in DMD is currently underway. This article summarizes the milestones in the development of givinostat leading to this first approval for DMD.

Discriminatory Properties of Quality-Adjusted Life-Years-Based Cost-Effectiveness Analyses for Patients With Disabilities: A Duchenne Muscular Dystrophy Case Study

ObjectivesQuality-adjusted life-years (QALYs) have been challenged as a measure of benefit for people with disabilities, particularly for those in low-utility health states or with irreversible disability. This study examined the impact of a QALY-based assessment on the price for a hypothetical treatment for Duchenne muscular dystrophy (DMD), a progressive, genetic neuromuscular disease. MethodsA previously published, 5-state model, which analyzed treatments for early ambulatory (EA) DMD patients, was replicated, validated, and adapted to include early nonambulatory (ENA) DMD patients. The model was used to assess a QALY-based threshold price (maximum cost-effective price) for a hypothetical treatment for 13-year-old ENA and 5-year-old EA patients (initial health states with lower and higher utility, respectively). All inputs were replicated including willingness-to-pay thresholds of $50 000 to $200 000/QALY. ResultsIn contrast to EA patients, ENA patients had a 98% modeled decline in QALY-based threshold price at a willingness-to-pay off $150 000/QALY or higher, despite equal treatment benefit (delayed progression/death). At $100 000/QALY or lower, net nontreatment costs exceeded health benefits, implying any treatment for ENA patients would not be considered cost-effective, even at $0 price, including an indefinite pause in disease progression. ConclusionsFor certain severe, disabling conditions, traditional approaches are likely to conclude that treatments are not cost-effective at any price once a patient progresses to a disabled health state with low utility value. These findings elucidate theoretical/ethical concerns regarding potential discriminatory properties of traditional QALY assessments for people with disabilities, particularly those who have lost ambulation or have other physical limitations.

A patient with Duchenne muscular dystrophy and complete AV block undergoing a successful left bundle area pacing implantation

A patient with Duchenne muscular dystrophy and complete AV block undergoing a successful left bundle area pacing implantation

Expression of Concern: Hippo signaling pathway is altered in Duchenne muscular dystrophy.

Expression of Concern: Hippo signaling pathway is altered in Duchenne muscular dystrophy.

Thrombospondin-4 deletion does not exacerbate muscular dystrophy in β-sarcoglycan-deficient and laminin α2 chain-deficient mice

Muscular dystrophy is a group of genetic disorders that lead to muscle wasting and loss of muscle function. Identifying genetic modifiers that alleviate symptoms or enhance the severity of a primary disease helps to understand mechanisms behind disease pathology and facilitates discovery of molecular targets for therapy. Several muscular dystrophies are caused by genetic defects in the components of the dystrophin-glycoprotein adhesion complex (DGC). Thrombospondin-4 overexpression has been shown to mitigate dystrophic disease in mouse models for Duchenne muscular dystrophy (dystrophin deficiency) and limb-girdle muscular dystrophy type 2F (LGMD2F, δ-sarcoglycan deficiency), while deletion of the thrombospondin-4 gene exacerbated the diseases. Hence, thrombospondin-4 has been considered a candidate molecule for therapy of muscular dystrophies involving the DGC. We have investigated whether thrombospondin-4 could act as a genetic modifier for other DGC-associated diseases: limb-girdle muscular dystrophy type 2E (LGMD2E, β-sarcoglycan deficiency) and laminin α2 chain-deficient muscular dystrophy (LAMA2-RD). Deletion of the thrombospondin-4 gene in mouse models for LGMD2E and LAMA2-RD, respectively, did not result in worsening of the dystrophic phenotype. Loss of thrombospondin-4 did not enhance sarcolemma damage and did not impair trafficking of transmembrane receptors integrin α7β1 and dystroglycan in double knockout muscles. Our results suggest that thrombospondin-4 might not be a relevant therapeutic target for all muscular dystrophies involving the DGC. This data also demonstrates that molecular pathology between very similar diseases like LGMD2E and 2F can differ significantly.

Recent Advances in Pre-Clinical Development of Adiponectin Receptor Agonist Therapies for Duchenne Muscular Dystrophy.

Duchenne muscular dystrophy (DMD) is caused by genetic mutations in the cytoskeletal-sarcolemmal anchor protein dystrophin. Repeated cycles of sarcolemmal tearing and repair lead to a variety of secondary cellular and physiological stressors that are thought to contribute to weakness, atrophy, and fibrosis. Collectively, these stressors can contribute to a pro-inflammatory milieu in locomotor, cardiac, and respiratory muscles. Given the many unwanted side effects that accompany current anti-inflammatory steroid-based approaches for treating DMD (e.g., glucocorticoids), there is a need to develop new therapies that address inflammation and other cellular dysfunctions. Adiponectin receptor (AdipoR) agonists, which stimulate AdipoR1 and R2 isoforms on various cell types, have emerged as therapeutic candidates for DMD due to their anti-inflammatory, anti-fibrotic, and pro-myogenic properties in pre-clinical human and rodent DMD models. Although these molecules represent a new direction for therapeutic intervention, the mechanisms through which they elicit their beneficial effects are not yet fully understood, and DMD-specific data is limited. The overarching goal of this review is to investigate how adiponectin signaling may ameliorate pathology associated with dystrophin deficiency through inflammatory-dependent and -independent mechanisms and to determine if current data supports their future progression to clinical trials.

Investigating the Involvement of C-X-C Motif Chemokine 5 and P2X7 Purinoceptor in Ectopic Calcification in Mouse Models of Duchenne Muscular Dystrophy.

Ectopic calcification of myofibers is an early pathogenic feature in patients and animal models of Duchenne muscular dystrophy (DMD). In previous studies using the Dmdmdx-βgeo mouse model, we found that the dystrophin-null phenotype exacerbates this abnormality and that mineralised myofibers are surrounded by macrophages. Furthermore, the P2X7 purinoceptor, functioning in immune cells offers protection against dystrophic calcification. In the present study, by exploring transcriptomic data from Dmdmdx mice, we hypothesised these effects to be mediated by C-X-C motif chemokine 5 (CXCL5) downstream of P2X7 activation. We found that CXCL5 is upregulated in the quadriceps muscles of Dmdmdx-βgeo mice compared to wild-type controls. In contrast, at the cell level, dystrophic (SC5) skeletal muscle cells secreted less CXCL5 chemokine than wild-type (IMO) controls. Although release from IMO cells was increased by P2X7 activation, this could not explain the elevated CXCL5 levels observed in dystrophic muscle tissue. Instead, we found that CXCL5 is released by dystrophin-null macrophages in response to P2X7 activation, suggesting that macrophages are the source of CXCL5 in dystrophic muscles. The effects of CXCL5 upon mineralisation were investigated using the Alizarin Red assay to quantify calcium deposition in vitro. In basal (low phosphate) media, CXCL5 increased calcification in IMO but not SC5 myoblasts. However, in cultures treated in high phosphate media, to mimic dysregulated phosphate metabolism occurring in DMD, CXCL5 decreased calcification in both IMO and SC5 cells. These data indicate that CXCL5 is part of a homoeostatic mechanism regulating intracellular calcium, that CXCL5 can be released by macrophages in response to the extracellular ATP damage-associated signal, and that CXCL5 can be part of a damage response to protect against ectopic calcification. This mechanism is affected by DMD gene mutations.

Mechanisms of Action of the US Food and Drug Administration-Approved Antisense Oligonucleotide Drugs.

Antisense oligonucleotides (ASOs) are single stranded nucleic acids that target RNA. The US Food and Drug Administration has approved ASOs for several diseases. ASOs utilize three principal modes of action (MOA). The first MOA is initiated by base-pairing between the ASO and its target mRNA, followed by RNase H-dependent mRNA degradation. The second MOA is triggered by ASOs that occlude splice acceptor sites in pre-mRNAs leading to skipping of a mutation-bearing exon. The third MOA involves ASOs that sterically hinder mRNA function, often inhibiting translation. ASOs contain a variety of modifications to the sugar-phosphate backbone and bases that stabilize the ASO or render them resistant to RNase activity. RNase H-dependent ASOs include inotersen and eplontersen (for hereditary transthyretin amyloidosis), fomiversen (for opportunistic cytomegalovirus infection), mipomersen (for familial hypercholesterolemia), and tofersen [for amyotrophic lateral sclerosis (ALS)]. Splice modulating ASOs include nursinersen (for spinal muscular atrophy) and eteplirsen, golodirsen, viltolarsen, and casimersen (all for the treatment of Duchenne muscular dystrophy). In addition, a designer ASO, milasen, was used to treat a single individual afflicted with Batten disease. Since ASO design relies principally upon knowledge of mRNA sequence, the bench to bedside pipeline for ASOs is expedient compared with protein-directed drugs.[Graphical abstract available.].

Frequency of Delayed Puberty in Boys with Contemporary Management of Duchenne Muscular Dystrophy.

Delayed puberty is thought to be common in boys with Duchenne muscular dystrophy (DMD) treated with long term oral glucocorticoid. This study aims to report the frequency of delayed puberty in DMD from examination by a paediatric endocrinologist alongside detailed endocrine investigations. All boys with DMD aged at least 14 years in January 2022 known to the paediatric neuromuscular service (2016-2022) were included in this study. Delayed puberty was defined based on testicular volume and genital staging in comparison to published puberty nomogram. Twenty-four out of 37 boys (65%) had evidence of delayed puberty, 23/24 (96%) of those with delayed puberty were on glucocorticoid therapy all of whom were on daily glucocorticoid. On the other hand, 7/13 (54%) of those with normal timing of puberty were on glucocorticoid; 2/7 (29%) were on the intermittent regimen. Of those who were on daily glucocorticoid therapy at the time of assessment of puberty, 23/28 (82%) had evidence of delayed puberty. In boys with delayed puberty, endocrine investigations showed low luteinizing hormone (LH) with undetectable testosterone levels, a pre-pubertal response with lutenizing hormone releasing hormone test and sub-optimal testosterone levels with prolonged human chorionic gonadotropin stimulation. The frequency of delayed puberty in boys with DMD was 65%. Eighty-two percent of adolescent boys with DMD on daily glucocorticoid had evidence of delayed puberty. Biochemical investigations point to functional central hypogonadism in these adolescents. Our data supports the routine monitoring of puberty in boys with DMD.

Acute microtubule changes linked to DMD pathology are insufficient to impair contractile function or enhance contraction-induced injury in healthy muscle.

Duchenne muscular dystrophy (DMD) is marked by the genetic deficiency of the dystrophin protein in striated muscle whose consequence is a cascade of cellular changes that predispose the susceptibility to contraction injury central to DMD pathology. Recent evidence identified the proliferation of microtubules enriched in post-translationally modified tubulin as a consequence of dystrophins absence that increases the passive mechanics of the muscle fiber and the excess mechanotransduction elicited reactive oxygen species and calcium signals that promote contraction injury. Motivated by evidence that acutely normalizing the disease microtubule alterations reduced contraction injury in murine DMD muscle ( mdx ), here we sought the direct impact of these microtubule alterations independent of dystrophins absence and the multitude of other changes consequent to dystrophic disease. To this end we used acute pharmacologic (epithiolone-D, EpoD; 4 hours) or genetic (vashohibin-2 and small vasohibin binding protein overexpression via AAV9; 2 weeks) strategies to effectively model the proliferation of detyrosination enriched microtubules in the mdx muscle. Quantifying in vivo nerve evoked plantarflexor function we find no alteration in peak torque nor contraction kinetics in WT mice modeling these DMD relevant MT alterations. Quantifying the susceptibility to eccentric contraction injury we show EpoD treatment proffered a small but significant protection from contraction injury while VASH/SVBP had no discernable impact. We conclude that the disease dependent MT alterations act in concert with additional cellular changes to predispose contraction injury in DMD.

A Systematic Review on the Application of Virtual Reality for Muscular Dystrophy Rehabilitation: Motor Learning Benefits.

Using virtual reality (VR) for Muscular Dystrophy (MD) rehabilitation promises to be a novel therapeutic approach, potentially enhancing motor learning, functional outcomes, and overall quality of life. This systematic review primarily aimed to provide a comprehensive summary of the current understanding regarding the application of VR in supporting MD rehabilitation. A systematic search was performed in PubMed, Scopus, Cochrane Library, and Web of Science to identify relevant articles. The inclusion criteria encompassed studies involving individuals diagnosed with MD who underwent VR interventions, with a primary focus on assessing functional improvement. Methodological quality of the studies was assessed by using the Physiotherapy Evidence Database (PEDro) scale. Seven studies, involving 440 individuals with Duchenne Muscular Dystrophy (DMD), were included in the review. Among these studies, six primarily explored the motor learning potential of VR, while one study investigated the impact of VR training on functional abilities. In conclusion, the qualitative synthesis supports VR-based interventions' potential positive effects on motor learning, performance improvement, and functional outcomes in individuals with DMD. However, current usage mainly focuses on assessing the potential mechanisms' benefits, suggesting the importance of expanding clinical adoption to harness their therapeutic potential for MD patients.

Adverse events associated with eteplirsen: A disproportionality analysis using the 2016–2023 FAERS data

BackgroundEteplirsen (Exondys 51) is an orphan drug approved for the treatment of Duchenne muscular dystrophy (DMD), having received accelerated approval from the U.S. Food and Drug Administration (FDA) in 2016. The primary aim of this study is to closely monitor adverse events (AEs) associated with eteplirsen and to identify emerging signals to better characterize their safety profile. MethodsAEs due to eteplirsen usage reported from the third quarter (Q3) of 2016 to the fourth quarter (Q4) of 2023 were collected from the FDA Adverse Event Reporting System (FAERS). The role_code of AEs mainly includes primary suspect (PS), secondary suspect (SS), concomitant (C), and interaction (I). This study targeted reports with a role_cod of ‘PS.’ According to the FDA deduplication rule, the latest FDA_DT is selected when the CASEID is the same, and the higher PRIMARYID is selected when the CASEID and FDA_DT are the same. Disproportionality analyses, encompassing four algorithms for reporting odds ratio (ROR), proportional reporting ratio (PRR), Bayesian configuration promotion neural network (BCPNN), and multi-item gamma Poisson shrinker (MGPS), were utilized to quantify the signals of AEs associated with eteplirsen. ResultsFrom the FAERS database, a total of 13,205,369 reports were amassed throughout the study duration. Following the eradication of duplicates, the number of reports with eteplirsen designated as the PS amounted to 1480 encompassed 25 organ systems. Among these, “general disorders and administration site conditions,” “injury, poisoning, and procedural complications,” “respiratory, thoracic, and mediastinal disorders,” “infections and infestations,” “vascular disorders,” and “product issues” met at least one of the four computational criteria. Additionally, 55 Preferred Terms (PTs) aligned with the prescribed algorithms. The median time to AEs in these patients was 903 days with an interquartile range (IQR) of 269–1575 days. Moreover, 70.04 % of AEs manifested one year or more after the initiation of treatment. ConclusionAs an orphan drug granted accelerated approval, our study has confirmed well-known adverse drug reactions and identified potential safety issues associated with eteplirsen treatment. This has contributed to a deeper understanding of the complex interrelations between adverse reactions and the use of eteplirsen. The findings underscore the critical importance of ongoing monitoring and sustained observation to promptly detect and effectively manage AEs, thereby enhancing the overall safety and well-being of patients treated with eteplirsen for DMD.

Periodic limb movements during sleep in children with neuromuscular disease or cerebral palsy – An important potential contributor to sleep-related morbidity

ObjectivesPoor sleep is frequently reported in children with neuromuscular diseases (NMD) and cerebral palsy (CP) however breathing disorders during sleep are often the clinical focus. Periodic limb movements (PLMs) have an increased prevalence in adults with NMD and may contribute to sleep disturbance in this population. We assessed the prevalence of PLMs in children with NMD or CP. MethodsRetrospective review of polysomnography (PSG) with leg electromyography in children age 1–18 years with NMD (including Duchenne muscular dystrophy, myotonic dystrophy, spinal muscular atrophy) or CP performed at a paediatric sleep centre 2004–2022. ResultsLeg electromyography was available in at least 1 PSG in 239 children (125 NMD, 114 CP), and in 2 PSGs in 105 children (73 NMD, 32 CP). At initial PSG, 72 (30 %) were female with a median age 9y and respiratory disturbance index 3.5/h (interquartile range 1.3–9.9/h). Elevated PLM index (PLMI; >5/h) occurred in 9.6 % of each of the CP and NMD groups, quantified by initial PSG. Overall, PLMI increased from baseline (median 0, maximum 33/h) to follow-up (median 0, maximum 55.8/h; p < 0.05). In those with an elevated PLMI, arousal percentage attributable to PLMs was up to 25 % (median 7.5 %). ConclusionsElevated PLMI occurred at a higher prevalence in children with NMD and CP than reported in other clinic-referred paediatric populations. It is important that PLMs are not overlooked as identification and treatment may help improve sleep outcomes. Further research is required to understand the pathophysiology and consequences of PLMs specifically in this population.

Diapocynin treatment induces functional and structural improvements in an advanced disease state in the mdx5Cv mice

Duchenne muscular dystrophy (DMD) is the most common muscular disorder affecting children. It affects nearly 1 male birth over 5000. Oxidative stress is a pervasive feature in the pathogenesis of DMD. Recent work shows that the main generators of ROS are NADPH oxidases (NOX), suggesting that they are an early and promising target in DMD. In addition, skeletal muscles of mdx mice, a murine model of DMD, overexpress NOXes. We investigated the impact of diapocynin, a dimer of the NOX inhibitor apocynin, on the chronic disease phase of mdx5Cv mice. Treatment of these mice with diapocynin from 7 to 10 months of age resulted in decreased hypertrophy of several muscles, prevented force loss induced by tetanic and eccentric contractions, improved muscle and respiratory functions, decreased fibrosis of the diaphragm and positively regulated the expression of disease modifiers. These encouraging results ensure the potential role of diapocynin in future treatment strategies.

Carrier screening for 223 monogenic diseases in Chinese population: a multi-center study in 33 104 individuals

To investigate the epidemiological characteristics and mutation spectrum of monogenic diseases in Chinese population through a large-scale, multicenter carrier screening. This study was conducted among a total of 33 104 participants (16 610 females) from 12 clinical centers across China.Carrier status for 223 genes was analyzed using high-throughput sequencing and different PCR methods. The overall combined carrier frequency was 55.58% for 197 autosomal genes and 1.84% for 26 X-linked genes in these participants.Among the 16 669 families, 874 at-risk couples (5.24%) were identified.Specifically, 584 couples (3.50%) were at risk for autosomal genes, 306(1.84%) for X-linked genes, and 16 for both autosomal and X-linked genes.The most frequently detected autosomal at-risk genes included GJB2(autosomal recessive deafness type 1A, 393 couples), HBA1/HBA2(α-thalassemia, 36 couples), PAH (phenylketonuria, 14 couples), and SMN1(spinal muscular atrophy, 14 couples).The most frequently detected X-linked at-risk genes were G6PD (G6PD deficiency, 236 couples), DMD (Duchenne muscular dystrophy, 23 couples), and FMR1(fragile X syndrome, 17 couples).After excluding GJB2 c.109G>A, the detection rate of at-risk couples was 3.91%(651/16 669), which was lowered to 1.72%(287/16 669) after further excluding G6PD.The theoretical incidence rate of severe monogenic birth defects was approximately 4.35‰(72.5/16 669).Screening for a battery of the top 22 most frequent genes in the at-risk couples could detect over 95% of at-risk couples, while screening for the top 54 genes further increased the detection rate to over 99%. This study reveals the carrier frequencies of 223 monogenic genetic disorders in the Chinese population and provides evidence for carrier screening strategy development and panel design tailored to the Chinese population.In carrier testing, genetic counseling for specific genes or gene variants can be challenging, and the couples need to be informed of these difficulties before testing and provided with options for not screening these genes or gene variants.