Social difficulties and care burden of adult Duchenne muscular dystrophy in Japan: a questionnaire survey based on the Japanese Registry of Muscular Dystrophy (Remudy).

BACKGROUND: Little is known about the social difficulties and health care needs of adult Duchenne muscular dystrophy (DMD) patients in Japan, as well as the financial and physical stress experienced by their caregivers. This study aimed to clarify the social circumstances surrounding adult DMD patients and assess the degree of involvement of family members in their care and the associated economic burden of the disorder in Japan. METHODS: Adult DMD patients were identified through the Registry of Muscular Dystrophy (Remudy) in Japan and invited to complete a questionnaire together with a caregiver. Data on health care use, quality of life, work status, informal care, and household expenses were collected to estimate the costs associated with DMD from social and caregiver household perspectives. RESULTS: In total, 234 (63.7%) of 367 adult DMD patients (mean age, 27.4 ± 6.0; range, 20-48 years) completed the questionnaire. Of these, 38 (21%) had developmental disorders (mental retardation, autism, and learning disorders), 57 (33%) experienced bullying in school, and 44 (77%) indicated the reason for bullying to be their physical handicap. Employment histories were noted by 72 (31%), although 23 (10%) lost their jobs mainly due to physical difficulties. Of the 234 patients, 164 (74%) lived with their relatives, and 78% of care time was supplied by family members, in particular, their mothers. The mean rate of care work provided by family members was 81%. Household income of families with an adult DMD patient was lower, whereas the rate of living with parent(s) and grandparent(s) was higher, in comparison with the general Japanese population. CONCLUSIONS: Adult DMD patients in Japan experience many social difficulties from childhood up to adulthood. As adults, many DMD patients experience bullying and workplace difficulties. Families were found to provide most of the care and financial support for DMD patients. Our results suggest the need to improve public patient care systems, including financial support, to address the physical and economic burdens of care for adult DMD patients in Japan.

Rare mosaic variant of GJA1 in a patient with a neurodevelopmental disorder.

GJA1 is the causative gene for oculodentodigital dysplasia (ODDD). A novel de novo GJA1 variant, NM 000165:c263C > T [p.P88L], was identified in a mosaic state in a patient with short stature, seizures, delayed myelination, mild hearing loss, and tooth enamel hypoplasia. Although the patient exhibited severe neurodevelopmental delay, other clinical features of ODDD, including limb anomalies, were mild. This may be due to differences in the mosaic ratios in different organs.

[Treatment of Juvenile Myasthenia Gravis].

The pathogenesis of juvenile myasthenia gravis is similar to that of adult-onset cases, but does differ significantly in that it is predominantly ocular type, has a low antibody-positive rate, a low thymoma complication rate, and a high remission rate. The evidence for the adult treatment strategy of low-dose steroids and fast-acting treatment is insufficient in children, and the safety of immunosuppressive drugs has not been established. Steroid use in children in particular requires caution due to the risk of growth retardation, and while lower doses are desirable, the efficacy of lower doses has not been as fully investigated as in adults. Conversely, experience has shown that the use of adequate doses of steroids results in high remission rates, and there is currently no rationale for recommending lower doses.

The Clinical Course and Treatment of a Case of Refractory Systemic Juvenile Myasthenia Gravis Successfully Treated with Thymectomy.

Juvenile myasthenia gravis (JMG) exhibits a more favorable response to glucocorticoids and has a better prognosis than adult myasthenia gravis. However, no established treatment exists for refractory JMG. Although thymectomy has been performed in several patients with refractory systemic JMG, there are few detailed clinical descriptions of patients who underwent thymectomy. Here, we present the case of a 10-year-old boy with refractory systemic JMG who was successfully treated with thymectomy. The patient developed symptoms, including dysphagia, malaise, diurnal ptosis, and weakness in the trunk muscles, and he was diagnosed with generalized JMG. Despite undergoing various treatments, including steroids, tacrolimus, steroid pulse therapy, intravenous immunoglobulin, azathioprine (AZT), and rituximab, his symptoms did not improve. Therefore, he underwent a thoracoscopic thymectomy 24 months after disease onset. Thymectomy led to remission, as demonstrated by a significant reduction in the quantitative myasthenia gravis score and anti-acetylcholine receptor antibody levels, which persisted for 43 months after surgery. Our case demonstrates the effectiveness of thymectomy in systemic JMG patients with positive anti-acetylcholine receptor antibodies, despite therapeutic failure with AZT and rituximab, within 2 years of disease onset.

Natural history of Becker muscular dystrophy: a multicenter study of 225 patients.

OBJECTIVE: Becker muscular dystrophy (BMD) is a milder variant of Duchenne muscular dystrophy (DMD), a lethal X-linked muscular disorder. Here, we aim to investigat the clinical involvement of skeletal, respiratory, cardiac, and central nervous systems in patients with BMD, as well as genotype-phenotype relationships. METHODS: This nationwide cohort study investigated the clinical manifestations and genotype-phenotype relationships in 225 patients with BMD having in-frame deletion from 22 medical centers. The primary outcome was to elucidate the association of genotype with skeletal muscle, respiratory, cardiac, and central nervous system disorders. Descriptive statistics were used to analyze the data. RESULTS: The average age of the subjects was 31.5 (range, 1-81) years. Initial symptoms of BMD were muscular (60%), followed by asymptomatic hypercreatine kinasemia (32.4%) and central nervous system disorders (5.3%). Gait disturbance was observed in 53.8% of patients and the average age at wheelchair introduction was 36.5 years. The ventilator introduction rate was 6.7% at an average age of 36.6 years. More than 30% of patients had an abnormal electrocardiogram and approximately 15% had heart failure symptoms. Cardiac function on echocardiography varied significantly among the patients. The frequencies of seizures and intellectual/developmental disability were 8.0% and 16.9%, respectively. Exon 45-47deletion (del) was the most common (22.6%), followed by exon 45-48del (13.1%). Patients with exon 45-49del patients demonstrated severe skeletal muscle damage. Patients with exon 45-47del and exon 45-55del patients did not require ventilator use. INTERPRETATION: The study provides important prognostic information for patients and clinicians to establish therapy plans and to implement preventative medicine.

Genetic and clinical landscape of childhood cerebellar hypoplasia and atrophy.

PURPOSE: Cerebellar hypoplasia and atrophy (CBHA) in children is an extremely heterogeneous group of disorders, but few comprehensive genetic studies have been reported. Comprehensive genetic analysis of CBHA patients may help differentiating atrophy and hypoplasia and potentially improve their prognostic aspects. METHODS: Patients with CBHA in 176 families were genetically examined using exome sequencing. Patients with disease-causing variants were clinically evaluated. RESULTS: Disease-causing variants were identified in 96 of the 176 families (54.5%). After excluding 6 families, 48 patients from 42 families were categorized as having syndromic associations with CBHA, whereas the remaining 51 patients from 48 families had isolated CBHA. In 51 patients, 26 aberrant genes were identified, of which, 20 (76.9%) caused disease in 1 family each. The most prevalent genes were CACNA1A, ITPR1, and KIF1A. Of the 26 aberrant genes, 21 and 1 were functionally annotated to atrophy and hypoplasia, respectively. CBHA+S was more clinically severe than CBHA-S. Notably, ARG1 and FOLR1 variants were identified in 2 families, leading to medical treatments. CONCLUSION: A wide genetic and clinical diversity of CBHA was revealed through exome sequencing in this cohort, which highlights the importance of comprehensive genetic analyses. Furthermore, molecular-based treatment was available for 2 families.

In utero transplantation of myoblasts and adipose-derived mesenchymal stem cells to murine models of Duchenne muscular dystrophy does not lead to engraftment and frequently results in fetal death.

Introduction: Duchenne muscular dystrophy (DMD) is a progressive disease that leads to damage of muscle and myocardium due to genetic abnormalities in the dystrophin gene. In utero cell transplantation that might facilitate allogenic transplantation is worth considering to treat this disease. Methods: We performed allogeneic in utero transplantation of GFP-positive myoblasts and adipose-derived mesenchymal stem cells into murine DMD model animals. The transplantation route in this study was fetal intraperitoneal transplantation and transplacental transplantation. Transplanted animals were examined at 4-weeks old by immunofluorescence staining and RT-qPCR. Results: No GFP-positive cells were found by immunofluorescence staining of skeletal muscle and no GFP mRNA was detected by RT-qPCR in any animal, transplantation method and cell type. Compared with previous reports, myoblast transplantation exhibited an equivalent mortality rate, but adipose-derived stem cell (ASC) transplantation produced a higher mortality rate. Conclusions: In utero transplantation of myoblasts or ASCs to murine models of DMD does not lead to engraftment and, in ASC transplantation primarily, frequently results in fetal death.

Laminin-221-derived recombinant fragment facilitates isolation of cultured skeletal myoblasts.

Introduction: Laminin is a major component of the basement membrane, containing multiple domains that bind integrin, collagen, nidogen, dystroglycan, and heparan sulfate. Laminin-221, expressed in skeletal and cardiac muscles, has strong affinity for the cell-surface receptor, integrin α7X2ß1. The E8 domain of laminin-221, which is essential for cell integrin binding, is commercially available as a purified recombinant protein fragment. In this study, recombinant E8 fragment was used to purify primary rodent myoblasts. We established a facile and inexpensive method for primary myoblast culture exploiting the high affinity binding of integrin α7X2ß1 to laminin-221. Methods: Total cell populations from dissociated muscle tissue were enzymatically digested and seeded onto laminin-221 E8 fragment-coated dishes. The culture medium containing non-adherent floating cells was removed after 2-hour culture at 37 °C. The adherent cells were subjected to immunofluorescence staining of desmin, differentiation experiments, and gene expression analysis. Results: The cells obtained were 70.3 ± 5.49% (n = 5) desmin positive in mouse and 67.7 ± 1.65% (n = 3) in rat. Immunofluorescent staining and gene expression analyses of cultured cells showed phenotypic traits of myoblasts. Conclusion: This study reports a novel facile method for primary culture of myoblasts obtained from mouse and rat skeletal muscle by exploiting the high affinity of integrin α7X2ß1 to laminin-221.

Efficacy of steroid therapy for Fukuyama congenital muscular dystrophy.

Although there is only symptomatic treatment for Fukuyama congenital muscular dystrophy (FCMD), several reports have suggested that steroid therapy could be effective for FCMD; however, no independent intervention studies have been conducted. This study aimed to evaluate the efficacy of steroid therapy for restoring motor functions in FCMD patients. This study involved 3-to-10-year-old FCMD patients who exhibited a decline in motor functions, requested steroid therapy. Patients with consent started oral administration of 0.5-mg/kg prednisolone every alternate day, which was increased to 1.0 mg/kg if the response was inadequate. We used the Gross Motor Function Measure (GMFM) to evaluate and compare the motor functions of all patients. Wilcoxon signed-rank test (significance level, P ≤ 0.05) was used for statistical analysis. At the onset of steroid therapy, 8.10 years (SD, 2.14 years) was the mean age of FCMD patients. The mean GMFM difference between before and after the steroid therapy was + 1.23 (SD, 1.10), and a P value of 0.015 represented significant improvement in GMFM. Our results indicate that steroid therapy may contribute to the maintenance and improvement of the motor functions of advanced-stage FCMD patients.Clinical Trial Registration Registration Number: UMIN000020715, Registration Date: Feb 1st, 2016 (01/02/2016).

Restoration of the defect in radial glial fiber migration and cortical plate organization in a brain organoid model of Fukuyama muscular dystrophy.

Fukuyama congenital muscular dystrophy (FCMD) is a severe, intractable genetic disease that affects the skeletal muscle, eyes, and brain and is attributed to a defect in alpha dystroglycan (αDG) O-mannosyl glycosylation. We previously established disease models of FCMD; however, they did not fully recapitulate the phenotypes observed in human patients. In this study, we generated induced pluripotent stem cells (iPSCs) from a human FCMD patient and differentiated these cells into three-dimensional brain organoids and skeletal muscle. The brain organoids successfully mimicked patient phenotypes not reliably reproduced by existing models, including decreased αDG glycosylation and abnormal radial glial (RG) fiber migration. The basic polycyclic compound Mannan-007 (Mn007) restored αDG glycosylation in the brain and muscle models tested and partially rescued the abnormal RG fiber migration observed in cortical organoids. Therefore, our study underscores the importance of αDG O-mannosyl glycans for normal RG fiber architecture and proper neuronal migration in corticogenesis.

[Questionnaire surveys of clinical genetic specialists on the medical genetics for patients with myotonic dystrophy type 1].

We conducted nationwide questionnaire surveys of medical genetics for patients with myotonic dystrophy type 1 to certified medical geneticists. Explanations about the patient's problems were influenced by geneticist's specialties and central nervous system disorders. Many geneticists answered that male patients are also eligible for prenatal/preimplantation genetic diagnosis, and they perform prenatal genetic diagnosis for men if asked. About 40% of respondents answered that criteria for preimplantation genetic diagnosis should be relaxed. Thus, we investigated the implementation status of prenatal/preimplantation genetic diagnosis at the participating facilities of the national liaison council for clinical sections of medical genetics. No facility had an experience of prenatal/preimplantation genetic diagnosis for male patients. Still, one facility was applying for preimplantation genetic diagnosis. The social consensus of reproductive medicine is influenced by technological progress and historical background. It is essential to eliminate the eugenic's idea and form a social consensus through sufficient discussions with participants from many areas, including the patients and their families.

Urinary titin as a biomarker in Fukuyama congenital muscular dystrophy.

Fukuyama congenital muscular dystrophy (FCMD) is the second most prevalent childhood-onset muscular dystrophy in Japan. It is an autosomal recessive disorder caused by the fukutin mutation (FKTN), characterized by muscle wasting and brain abnormalities. So far, serum creatine kinase (CK) is recognized as the only biomarker for FCMD. Recently, an ELISA assay to quantify the N-terminal fragment of titin in urine was developed. Urinary titin concentration is elevated in patients with Duchenne muscular dystrophy (DMD) compared to normal controls. Levels vary according to age with excellent sensitivity and specificity for detecting DMD, and they can be used as a diagnostic and disease progression marker. In this study, we measured the urinary titin concentration of 18 patients with FCMD. It was remarkably higher than normal controls and correlated with CK. Especially in homozygotes, the score for gross motor function measure, which is a quantitative motor scale for FCMD, was correlated with urinary titin concentration. Elevated urinary titin concentrations were thought to be reflective of a common pathophysiology with DMD. Urinary titin concentrations can assist with making the diagnosis of FCMD and to estimate the patient's motor function at that point.

Potential patient screening for late-onset Pompe disease in suspected sleep apnea: a rationale and study design for a Prospective Multicenter Observational Cohort Study in Japan (PSSAP-J Study).

BACKGROUND: Pompe disease is an autosomal recessive disorder caused by deficiency of the acid α-glucosidase (GAA) enzyme. GAA deficiency induces progressive glycogen accumulation which leads to weakness of the respiratory muscle including the diaphragm. Pompe disease is one of the few myopathies, for which an established therapy is available. Thus, earlier detection of potential late-onset Pompe disease (LOPD) and earlier intervention would have a significant clinical impact. PURPOSE: Our hypothesis is that sleep problems including sleep disordered breathing (SDB) and clinical symptoms may indicate an early stage of LOPD since decreased respiratory muscle activity generally first presents during sleep. Thus, the aims of this prospective, multicenter observational cohort study in Japan (PSSAP-J) are to demonstrate a higher prevalence of LOPD in a sleep lab-based population (primary outcome), and to identify predictive factors for LOPD from findings in diagnostic polysomnography (PSG) and clinical symptoms (secondary outcomes). METHODS: The study design is a prospective multicenter observational cohort study. Consecutive patients who present to sleep labs due to suspected SDB for an overnight PSG will be enrolled. All patients will be measured for creatine kinase, GAA activity, and if necessary, genetic analysis of GAA. Furthermore, chest X-ray, pulmonary function test, and arterial blood gas analysis will be collected. Then, prevalence and specific findings of LOPD will be assessed. RESULT: Congenital myopathy shows a shift from slow-deep to rapid-shallow breathing during transition from wakefulness to sleep accompanying a symptom of waking with gasping (actual further results are pending). DISCUSSION: The distribution in respiratory physiology between during wakefulness and sleep specific to LOPD may provide insights into early-stage detection. CLINICAL TRIAL REGISTRATION NUMBER: UMIN000039191, UMIN Clinical Trials Registry ( http://www.umin.ac.jp/ctr ).

Novel EXOSC9 variants cause pontocerebellar hypoplasia type 1D with spinal motor neuronopathy and cerebellar atrophy.

Pontocerebellar hypoplasia (PCH) is currently classified into 13 subgroups and many gene variants associated with PCH have been identified by next generation sequencing. PCH type 1 is a rare heterogeneous neurodegenerative disorder. The clinical presentation includes early-onset severe developmental delay, progressive motor neuronopathy, and cerebellar and pontine atrophy. Recently two variants in the EXOSC9 gene (MIM: 606180), NM_001034194.1: c.41T>C (p.Leu14Pro) and c.481C>T (p.Arg161*) were identified in four unrelated patients with PCH type 1D (PCH1D) (MIM: 618065). EXOSC9 encodes a component of the exosome complex, which is essential for correct processing and degradation of RNA. We report here two PCH1D families with biallelic EXOSC9 variants: c.239T>G (p.Leu80Arg) and c.484dupA (p.Arg162Lysfs*3) in one family and c.151G>C (p.Gly51Arg) in the other family. Although the patients studied here showed similar clinical features as previously described for PCH1D, relatively greater intellectual development (although still highly restricted) and normal pontine structure were recognized. Our findings expand the clinical consequences of biallelic EXOSC9 variants.

Infection-associated decrease of serum creatine kinase levels in Fukuyama congenital muscular dystrophy.

BACKGROUND: Marked decreases in serum creatine kinase levels have been noted in Duchenne and Becker muscular dystrophies as rare complications of autoimmune or autoinflammatory diseases. SUBJECTS AND METHODS: The influence of systemic inflammation on serum creatine kinase levels was reviewed from the charts of three subjects with Fukuyama congenital muscular dystrophy. RESULTS: A total of 30 infectious events were identified. Elevated serum C-reactive protein levels coincided with decreased creatine kinase levels on 19 occasions. In one subject, administration of 2 mg/kg/d prednisolone for bronchial asthma resulted in a decrease in creatine kinase level on six other occasions. CONCLUSION: Apart from an increase in endogenous cortisol secretion, certain inflammation-related molecules could play a role in mitigating muscle cell damage in Fukuyama congenital muscular dystrophy during febrile infectious episodes. Corticosteroids may be a promising agent for the treatment of muscular symptoms in this disorder.

A short form of gross motor function measure for Fukuyama congenital muscular dystrophy.

OBJECTIVES: The objective of this study was to confirm the validity of a short form of gross motor function measure for Fukuyama congenital muscular dystrophy (GMFM for FCMD). METHODS: This study is a case series and was conducted at the Tokyo Women's Medical University. Fifteen patients with FCMD were assessed using both the GMFM for FCMD with 68 items, which was created as a motor function measure for patients with FCMD on the basis of Rasch analysis, and the original GMFM with 88 items. The correlation between the GMFM for FCMD and the Ueda classification was assessed. Time required for each assessment was also evaluated. RESULTS: We found significant correlation between the GMFM for FCMD and the Ueda classification (r = 0.935); furthermore, the mean assessment time tended to decrease when using the GMFM for FCMD. CONCLUSIONS: GMFM for FCMD may be an appropriate motor function scale for patients with FCMD and might help decrease the assessment time.

Early phase 2 trial of TAS-205 in patients with Duchenne muscular dystrophy.

OBJECTIVE: Duchenne muscular dystrophy (DMD) is a progressive muscular disease characterized by chronic cycles of inflammatory and necrotic processes. Prostaglandin D2 (PGD2 ) is produced by hematopoietic PGD synthase (HPGDS), which is pathologically implicated in muscle necrosis. This randomized, double-blind, placebo-controlled early phase 2 study (NCT02752048) aimed to assess the efficacy and safety of the novel selective HPGDS inhibitor, TAS-205, with exploratory measures in male DMD patients aged ≥5 years. METHODS: Patients were randomized 1:1:1 to receive low-dose TAS-205 (6.67-13.33 mg/kg/dose), high-dose TAS-205 (13.33-26.67 mg/kg/dose), or placebo. The primary endpoint was the change from baseline in a 6-minute walk distance (6MWD) at Week 24. RESULTS: Thirty-six patients were enrolled, of whom 35 patients were analysed for safety. The mean (standard error) changes from baseline to Week 24 in 6MWD were -17.0 (17.6) m in the placebo group (n = 10), -3.5 (20.3) m in the TAS-205 low-dose group (n = 11), and -7.5 (11.2) m in the TAS-205 high-dose group (n = 11). The mean (95% confidence interval) difference from the placebo group was 13.5 (-43.3 to 70.2) m in the TAS-205 low-dose group and 9.5 (-33.3 to 52.4) m in the TAS-205 high-dose group. No obvious differences were observed in the incidences of adverse events between treatment groups. No adverse drug reactions specific to TAS-205 treatment were observed. INTERPRETATION: The HPGDS inhibitor TAS-205 showed a favorable safety profile in DMD patients. Further research is required to examine the effectiveness of TAS-205 in a larger trial.

[Study of medical practices for patients with myotonic dystrophy in Japan-Nationwide specialist survey].

To reveal current status of medical practice, we made a nationwide self-questionnaire survey to Japanese certified Neurologists and Child Neurologists. Most specialists seeing patients with myotonic dystrophy (DM) were aware that genetic analysis is approved in health insurance. The ratio of pre-explanation about genetic analysis was also high however written informed consent was not always obtained. Over 60% of specialists regarded motor dysfunction, conduction block/arrhythmia, heart failure, dysphagia, hypoventilation as important complications, while no more than 35% of specialists regarded hypoxia/apnea, multi-organ complications, which are feature of myotonic dystrophy, as important. Over half specialists did not check Holter electrocardiogram, sleep respiratory examination, or swallowing function regularly. This fact implied that cumbersome examinations tended to be refrained from regular assessment. Child neurologists were more aggressive in respiratory care and consultation of cardiovascular specialists. A few neurologists hesitated to introduce mechanical ventilation and tube feeding.