The practice of active patient involvement in rare disease research using ICT: experiences and lessons from the RUDY JAPAN project

BACKGROUND

The role of patients in medical research is changing, as more emphasis is being placed on patient involvement, and patient reported outcomes are increasingly contributing to clinical decision-making. Information and communication technology provides new opportunities for patients to actively become involved in research. These trends are particularly noticeable in Europe and the US, but less obvious in Japan. The aim of this study was to investigate the practice of active involvement of patients in medical research in Japan by utilizing a digital platform, and to analyze the outcomes to clarify what specific approaches could be put into practice.

METHODS

We developed the RUDY JAPAN system, an ongoing rare disease medical research platform, in collaboration with the Rare and Undiagnosed Diseases Study (RUDY) project in the UK. After 2 years of preparation, RUDY JAPAN was launched in December 2017. Skeletal muscle channelopathies were initially selected as target diseases, and hereditary angioedema was subsequently added. Several approaches for active patient involvement were designed through patient-researcher collaboration, namely the Steering Committee, questionnaire development, dynamic consent, and other communication strategies. We analyzed our practices and experiences focusing on how each approach affected and contributed to the research project.

RESULTS

RUDY JAPAN has successfully involved patients in this research project in various ways. While not a part of the initial decision-making phase to launch the project, patients have increasingly been involved since then. A high level of patient involvement was achieved through the Steering Committee, a governance body that has made a major contribution to RUDY JAPAN, and the process of the questionnaire development. The creation of the Patient Network Forum, website and newsletter cultivated dialogue between patients and researchers. The registry itself allowed patient participation through data input and control of data usage through dynamic consent.

CONCLUSIONS

We believe the initial outcomes demonstrate the feasibility and utility of active patient involvement in Japan. The collaboration realized through RUDY JAPAN was enabled by digital technologies. It allowed busy patients and researchers to find the space to meet and work together for the Steering Committee, questionnaire development and various communication activities. While the practice of active patient involvement in Japan is still in its early stages, this research confirms its viability if the right conditions are in place. (331 words).

Cardiac Conduction Disorders as Markers of Cardiac Events in Myotonic Dystrophy Type 1

Background Myotonic dystrophy type 1 involves cardiac conduction disorders. Cardiac conduction disease can cause fatal arrhythmias or sudden death in patients with myotonic dystrophy type 1. Methods and Results This study enrolled 506 patients with myotonic dystrophy type 1 (aged ≥15 years; >50 cytosine-thymine-guanine repeats) and was treated in 9 Japanese hospitals for neuromuscular diseases from January 2006 to August 2016. We investigated genetic and clinical backgrounds including health care, activities of daily living, dietary intake, cardiac involvement, and respiratory involvement during follow-up. The cause of death or the occurrence of composite cardiac events (ie, ventricular arrhythmias, advanced atrioventricular blocks, and device implantations) were evaluated as significant outcomes. During a median follow-up period of 87 months (Q1-Q3, 37-138 months), 71 patients expired. In the univariate analysis, pacemaker implantations (hazard ratio [HR], 4.35; 95% CI, 1.22-15.50) were associated with sudden death. In contrast, PQ interval ≥240 ms, QRS duration ≥120 ms, nutrition, or respiratory failure were not associated with the incidence of sudden death. The multivariable analysis revealed that a PQ interval ≥240 ms (HR, 2.79; 95% CI, 1.9-7.19, P<0.05) or QRS duration ≥120 ms (HR, 9.41; 95% CI, 2.62-33.77, P < 0.01) were independent factors associated with a higher occurrence of cardiac events than those observed with a PQ interval <240 ms or QRS duration <120 ms; these cardiac conduction parameters were not related to sudden death. Conclusions Cardiac conduction disorders are independent markers associated with cardiac events. Further investigation on the prediction of occurrence of sudden death is warranted.

Cardiac Emerinopathy: A Nonsyndromic Nuclear Envelopathy With Increased Risk of Thromboembolic Stroke Due to Progressive Atrial Standstill and Left Ventricular Noncompaction

BACKGROUND

Mutations in the nuclear envelope genes encoding LMNA and EMD are responsible for Emery-Dreifuss muscular dystrophy. However, LMNA mutations often manifest dilated cardiomyopathy with conduction disturbance without obvious skeletal myopathic complications. On the contrary, the phenotypic spectrums of EMD mutations are less clear. Our aims were to determine the prevalence of nonsyndromic forms of emerinopathy, which may underlie genetically undefined isolated cardiac conduction disturbance, and the etiology of thromboembolic complications associated with EMD mutations.

METHODS

Targeted exon sequencing was performed in 87 probands with familial sick sinus syndrome (n=36) and a progressive cardiac conduction defect (n=51).

RESULTS

We identified 3 X-linked recessive EMD mutations (start-loss, splicing, missense) in families with cardiac conduction disease. All 3 probands shared a common clinical phenotype of progressive atrial arrhythmias that ultimately resulted in atrial standstill associated with left ventricular noncompaction (LVNC), but they lacked early contractures and progressive muscle wasting and weakness characteristic of Emery-Dreifuss muscular dystrophy. Because the association of LVNC with EMD has never been reported, we further genetically screened 102 LVNC patients and found a frameshift EMD mutation in a boy with progressive atrial standstill and LVNC without complications of muscular dystrophy. All 6 male EMD mutation carriers of 4 families underwent pacemaker or defibrillator implantation, whereas 2 female carriers were asymptomatic. Notably, a strong family history of stroke observed in these families was probably due to the increased risk of thromboembolism attributable to both atrial standstill and LVNC.

CONCLUSIONS

Cardiac emerinopathy is a novel nonsyndromic X-linked progressive atrial standstill associated with LVNC and increased risk of thromboembolism.

Hypokalaemic periodic paralysis with a charge-retaining substitution in the voltage sensor

Familial hypokalaemic periodic paralysis is a rare skeletal muscle disease caused by the dysregulation of sarcolemmal excitability. Hypokalaemic periodic paralysis is characterized by repeated episodes of paralytic attacks with hypokalaemia, and several variants in CACNA1S coding for Ca_V1.1 and SCN4A coding for Na_V1.4 have been established as causative mutations. Most of the mutations are substitutions to a non-charged residue, from the positively charged arginine (R) in transmembrane segment 4 (S4) of a voltage sensor in either Ca_V1.1 or Na_V1.4. Mutant channels have aberrant leak currents called 'gating pore currents', and the widely accepted consensus is that this current is the essential pathological mechanism that produces susceptibility to anomalous depolarization and failure of muscle excitability during a paralytic attack. Here, we have identified five hypokalaemic periodic paralysis cases from two different ethnic backgrounds, Japanese and French, with charge-preserving substitutions in S4 from arginine, R, to lysine, K. An R to K substitution has not previously been reported for any other hypokalaemic periodic paralysis families. One case is R219K in Na_V1.4, which is located at the first charge in S4 of Domain I. The other four cases all have R897K in Ca_V1.1, which is located at the first charge in S4 of Domain III. Gating pore currents were not detected in expression studies of Ca_V1.1-R897K. Na_V1.4-R219K mutant channels revealed a distinct, but small, gating pore current. Simulation studies indicated that the small-amplitude gating pore current conducted by Na_V1.4-R219K is not likely to be sufficient to be a risk factor for depolarization-induced paralytic attacks. Our rare cases with typical hypokalaemic periodic paralysis phenotypes do not fit the canonical view that the essential defect in hypokalaemic periodic paralysis mutant channels is the gating pore current and raise the possibility that hypokalaemic periodic paralysis pathogenesis might be heterogeneous and diverse.

EF hand-like motif mutations of Nav1.4 C-terminus cause myotonic syndrome by impairing fast inactivation

INTRODUCTION

Mutations of the voltage-gated sodium channel gene (SCN4A), which encodes Nav1.4, cause nondystrophic myotonia that occasionally is associated with severe apnea and laryngospasm. There are case reports of nondystrophic myotonia due to mutations in the C-terminal tail (CTerm) of Nav1.4, but the functional analysis is scarce.

METHODS

We present two families with nondystrophic myotonia harboring a novel heterozygous mutation (E1702del) and a known heterozygous mutation (E1702K).

RESULTS

The proband with E1702K exhibited repeated rhabdomyolysis, and the daughter showed laryngospasm and cyanosis. Functional analysis of the two mutations as well as another known heterozygous mutation (T1700_E1703del), all located on EF hand-like motif in CTerm, was conducted with whole-cell recording of heterologously expressed channel. All mutations displayed impaired fast inactivation.

DISCUSSION

The CTerm of Nav1.4 is vital for regulating fast inactivation. The study highlights the importance of accumulating pathological mutations of Nav1.4 and their functional analysis data.

[Study of care practices for patients with myotonic dystrophy in Japan-Nationwide patient survey]

We conducted a comprehensive anonymous questionnaire survey on medical care and treatment for patients with myotonic dystrophy, who registered in the Japanese national registry (Remudy) or were undergoing care in seven hospitals specializing neuromuscular diseases. The questionnaire consisted of 49 questions were distributed to 813 patients, and 342 valid responses were collected. Most prevalent symptoms or complaints were dysfunction of fingers and fatigue. One-third of the adult patients left the job, half of which was due to the disease. Twelve percent of the patients did not visit the specialist regularly, the main reason being distance. The most common reason that the patients did not follow the advice of using a ventilator by medical professionals was lack of feeling the need. One-fourth of the adult female patients had infertility treatment, 80% of which was before a diagnosis of this disorder. This first-time nationwide survey revealed the actual condition of Japanese patients with myotonic dystrophy and raised various care-related issues.

The expanding phenotype of hypokalemic periodic paralysis in a Japanese family with p.Val876Glu mutation in CACNA1S

BACKGROUND

Hypokalemic periodic paralysis (HypoPP) is an autosomal dominant disease characterized by the episodic weakness of skeletal muscles and hypokalemia. More than half patients with HypoPP carry mutations in CACNA1S, encoding alpha-1 subunit of calcium channel. Few reports have documented the non-neuromuscular phenotypes of HypoPP.

METHODS

The proband is a Japanese woman who developed HypoPP at 6 years of age. An excessive insulin secretion with the oral glucose tolerance test rationalized that she had experienced frequent attacks of paralysis on high-carbohydrate diets.

RESULTS

Voglibose and acetazolamide effectively controlled her paralytic episodes. Her 8-year-old son and 2-year-old daughter started showing the paralytic symptoms from 4 and 2 years of age, respectively. Laboratory tests revealed high concentrations of creatinine kinase in serum and elevated renin activities in plasma of these children. The targeted sequencing confirmed that these three patients had an identical heterozygous mutation (p.V876E) in CACNA1S.

CONCLUSION

Our data indicate that the p.V876E mutation in CACNA1S contributes to the early onset of neuromuscular symptoms and unusual clinical phenotypes of HypoPP.

[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.

A slipped-CAG DNA-binding small molecule induces trinucleotide-repeat contractions in vivo

In many repeat diseases, such as Huntington's disease (HD), ongoing repeat expansions in affected tissues contribute to disease onset, progression and severity. Inducing contractions of expanded repeats by exogenous agents is not yet possible. Traditional approaches would target proteins driving repeat mutations. Here we report a compound, naphthyridine-azaquinolone (NA), that specifically binds slipped-CAG DNA intermediates of expansion mutations, a previously unsuspected target. NA efficiently induces repeat contractions in HD patient cells as well as en masse contractions in medium spiny neurons of HD mouse striatum. Contractions are specific for the expanded allele, independently of DNA replication, require transcription across the coding CTG strand and arise by blocking repair of CAG slip-outs. NA-induced contractions depend on active expansions driven by MutSβ. NA injections in HD mouse striatum reduce mutant HTT protein aggregates, a biomarker of HD pathogenesis and severity. Repeat-structure-specific DNA ligands are a novel avenue to contract expanded repeats.

Functional analysis of a double-point mutation in the KCNJ2 gene identified in a family with Andersen-Tawil syndrome

Andersen-Tawil syndrome (ATS) is a skeletal muscle channelopathy with autosomal dominant inheritance resulting in periodic paralysis, arrhythmia characterized by QT prolongation, and dysmorphic features. The KCNJ2 gene has been identified as the causative gene of ATS. Herein, we reported 2 cases of a 21-year-old man and his mother, with episodic paralytic attacks and/or arrhythmia, which are characteristic of ATS. Both G144A, a reported ATS mutation, and V296F, a novel mutation, were identified in the KCNJ2 gene on the same allele from the proband and his mother, but not from his father. In the present study, we investigated the functional effect of these variants on the potassium channel Kir2.1 and the significance of the double mutation. G144A, V296F, and G144A-V296F mutant channels expressed in cultured cells revealed a loss-of-function effect of these mutations on Kir2.1. The K⁺ currents of G144A and G144A-V296F channels were more suppressed than that of V296F channel alone, whereas was no difference between G144A and G144A-V296F. To our knowledge, a double mutation in the KCNJ2 gene has not been reported previously. While either of 2 mutations potentially causes ATS, the G144A mutation might cause the dominant effect on the patients' clinical presentation.

Straightjacket/α2δ3 deregulation is associated with cardiac conduction defects in myotonic dystrophy type 1

Cardiac conduction defects decrease life expectancy in myotonic dystrophy type 1 (DM1), a CTG repeat disorder involving misbalance between two RNA binding factors, MBNL1 and CELF1. However, how DM1 condition translates into conduction disorders remains poorly understood. Here we simulated MBNL1 and CELF1 misbalance in the Drosophila heart and performed TU-tagging-based RNAseq of cardiac cells. We detected deregulations of several genes controlling cellular calcium levels, including increased expression of straightjacket/α2δ3, which encodes a regulatory subunit of a voltage-gated calcium channel. Straightjacket overexpression in the fly heart leads to asynchronous heartbeat, a hallmark of abnormal conduction, whereas cardiac straightjacket knockdown improves these symptoms in DM1 fly models. We also show that ventricular α2δ3 expression is low in healthy mice and humans, but significantly elevated in ventricular muscles from DM1 patients with conduction defects. These findings suggest that reducing ventricular straightjacket/α2δ3 levels could offer a strategy to prevent conduction defects in DM1.

The myotonic dystrophy health index: Japanese adaption and validity testing

INTRODUCTION

The Myotonic Dystrophy Health Index (MDHI) is a disease-specific, patient-reported outcome measure. The objective of this study was to translate, evaluate, and validate a Japanese version of the MDHI (MDHI-J).

METHODS

We utilized forward and backward translations and qualitative interviews with 11 myotonic dystrophy type 1 (DM1) participants. We subsequently tested the internal consistency, test-retest reliability, concurrent validity against muscle strength, and 3 quality-of-life measures, and the known-groups validity of the MDHI-J with 60 adult patients.

RESULTS

The MDHI-J was found to be culturally appropriate, comprehensive, and clinically relevant. The MDHI-J and its subscales had high internal consistency (mean Cronbach's α = 0.91), test-retest reliability (intraclass coefficient 0.678-0.915), and concurrent validity (Spearman's ρ - 0.869 to 0.904). MDHI-J scores were strongly associated with employment, duration of symptoms, and modified Rankin Scale.

DISCUSSION

The MDHI-J is suitable and valid to measure patient-reported disease burden in adult Japanese patients with DM1. Muscle Nerve 59:577-577, 2019.

Eight years after an international workshop on myotonic dystrophy patient registries: case study of a global collaboration for a rare disease

BACKGROUND

Myotonic Dystrophy is the most common form of muscular dystrophy in adults, affecting an estimated 10 per 100,000 people. It is a multisystemic disorder affecting multiple generations with increasing severity. There are currently no licenced therapies to reverse, slow down or cure its symptoms. In 2009 TREAT-NMD (a global alliance with the mission of improving trial readiness for neuromuscular diseases) and the Marigold Foundation held a workshop of key opinion leaders to agree a minimal dataset for patient registries in myotonic dystrophy. Eight years after this workshop, we surveyed 22 registries collecting information on myotonic dystrophy patients to assess the proliferation and utility the dataset agreed in 2009. These registries represent over 10,000 myotonic dystrophy patients worldwide (Europe, North America, Asia and Oceania).

RESULTS

The registries use a variety of data collection methods (e.g. online patient surveys or clinician led) and have a variety of budgets (from being run by volunteers to annual budgets over €200,000). All registries collect at least some of the originally agreed data items, and a number of additional items have been suggested in particular items on cognitive impact.

CONCLUSIONS

The community should consider how to maximise this collective resource in future therapeutic programmes.

rbFOX1/MBNL1 competition for CCUG RNA repeats binding contributes to myotonic dystrophy type 1/type 2 differences

Myotonic dystrophy type 1 and type 2 (DM1, DM2) are caused by expansions of CTG and CCTG repeats, respectively. RNAs containing expanded CUG or CCUG repeats interfere with the metabolism of other RNAs through titration of the Muscleblind-like (MBNL) RNA binding proteins. DM2 follows a more favorable clinical course than DM1, suggesting that specific modifiers may modulate DM severity. Here, we report that the rbFOX1 RNA binding protein binds to expanded CCUG RNA repeats, but not to expanded CUG RNA repeats. Interestingly, rbFOX1 competes with MBNL1 for binding to CCUG expanded repeats and overexpression of rbFOX1 partly releases MBNL1 from sequestration within CCUG RNA foci in DM2 muscle cells. Furthermore, expression of rbFOX1 corrects alternative splicing alterations and rescues muscle atrophy, climbing and flying defects caused by expression of expanded CCUG repeats in a Drosophila model of DM2.

Validation of The Individualized Neuromuscular Quality of Life in Japanese patients with myotonic dystrophy

INTRODUCTION

The Individualized Neuromuscular Quality of Life (INQoL) is used to measure the quality of life (QoL) of patients with neuromuscular disease. We conducted this study to translate and validate the Japanese version of the INQoL in patients with myotonic dystrophy.

METHODS

Forward and backward translation, patient testing, and psychometric validation were performed. We used the 36-Item Short Form Health Survey (SF-36) and the modified Rankin scale for concurrent validation.

RESULTS

The Japanese INQoL was administered to 90 adult patients. The coefficients for internal consistency and test-retest reliability were adequately high in most domains (Cronbach α 0.88-0.96 and intraclass coefficient 0.64-0.99). INQoL domains were moderately to strongly associated with relevant SF-36 subscales (Spearman's ρ -0.23 to -0.74). Symptom severity, disease duration, employment status, and use of a ventilator influenced overall QoL.

DISCUSSION

The INQoL is a reliable and validated measure of QoL for Japanese patients with myotonic dystrophy. Muscle Nerve, 2018.

Cognitive impairment and quality of life in patients with myotonic dystrophy type 1

INTRODUCTION

This study sought to clarify whether specific cognitive abilities are impaired in patients with myotonic dystrophy type 1 (DM1) as well as to investigate the relationships among quality of life (QoL), cognitive function, and psychological factors.

METHODS

Sixty patients with DM1 were evaluated on cognitive functioning (abstract reasoning, attention/working memory, executive function, processing speed, and visuoconstructive ability), apathy, depression, excessive daytime sleepiness, fatigue, and QoL. QoL was assessed by 2 domains of the Muscular Dystrophy Quality of Life Scale (Psychosocial Relationships and Physical Functioning and Health).

RESULTS

More than half of the patients exhibited cognitive impairment in attention/working memory, executive function, processing speed, and visuoconstructive ability. The Psychosocial Relationships factor was associated with processing speed, attention/working memory, and apathy, whereas depression and fatigue were associated with 2 QoL domains.

DISCUSSION

Our study identified specific cognitive impairments in DM1. Specific cognitive functions and psychological factors may be potential contributors to QoL. Muscle Nerve 57: 742-748, 2018.

GNE myopathy caused by a synonymous mutation leading to aberrant mRNA splicing

GNE myopathy is a rare autosomal recessive myopathy caused by bi-allelic mutations in GNE. We report the case of a 36-year-old man who presented with typical clinical and pathological features of GNE myopathy including distal dominant muscle weakness from the age of 29 and numerous rimmed vacuoles on muscle biopsy. Targeted next-generation sequencing revealed a novel synonymous mutation, c.1500A>G (p.G500=), together with a common Japanese mutation c.620A>T (p.D207V). The cDNA analysis of the biopsied muscle revealed that this synonymous mutation creates a cryptic splice donor site that causes aberrant splicing. This report will expand our understanding of the genetic heterogeneity of GNE myopathy emphasizing the importance of interpreting synonymous variants in genetic testing.

Aberrant Myokine Signaling in Congenital Myotonic Dystrophy

Myotonic dystrophy types 1 (DM1) and 2 (DM2) are dominantly inherited neuromuscular disorders caused by a toxic gain of function of expanded CUG and CCUG repeats, respectively. Although both disorders are clinically similar, congenital myotonic dystrophy (CDM), a severe DM form, is found only in DM1. CDM is also characterized by muscle fiber immaturity not observed in adult DM, suggesting specific pathological mechanisms. Here, we revealed upregulation of the interleukin-6 (IL-6) myokine signaling pathway in CDM muscles. We also found a correlation between muscle immaturity and not only IL-6 expression but also expanded CTG repeat length and CpG methylation status upstream of the repeats. Aberrant CpG methylation was associated with transcriptional dysregulation at the repeat locus, increasing the toxic RNA burden that upregulates IL-6. Because the IL-6 pathway is involved in myocyte maturation and muscle atrophy, our results indicate that enhanced RNA toxicity contributes to severe CDM phenotypes through aberrant IL-6 signaling.

Myotonic dystrophy type 1 patient-derived iPSCs for the investigation of CTG repeat instability

Myotonic dystrophy type 1 (DM1) is an autosomal-dominant multi-system disease caused by expanded CTG repeats in dystrophia myotonica protein kinase (DMPK). The expanded CTG repeats are unstable and can increase the length of the gene with age, which worsens the symptoms. In order to establish a human stem cell system suitable for the investigation of repeat instability, DM1 patient-derived iPSCs were generated and differentiated into three cell types commonly affected in DM1, namely cardiomyocytes, neurons and myocytes. Then we precisely analysed the CTG repeat lengths in these cells. Our DM1-iPSCs showed a gradual lengthening of CTG repeats with unchanged repeat distribution in all cell lines depending on the passage numbers of undifferentiated cells. However, the average CTG repeat length did not change significantly after differentiation into different somatic cell types. We also evaluated the chromatin accessibility in DM1-iPSCs using ATAC-seq. The chromatin status in DM1 cardiomyocytes was closed at the DMPK locus as well as at SIX5 and its promoter region, whereas it was open in control, suggesting that the epigenetic modifications may be related to the CTG repeat expansion in DM1. These findings may help clarify the role of repeat instability in the CTG repeat expansion in DM1.

[Myotonic Dystrophy: Advances in Translational Research]

Myotonic dystrophy (DM) is the most common form of muscular dystrophy in adults, which is caused by unstable genomic expansions of CTG or CCTG repeats. Mutant RNA transcripts containing the expanded repeats cause toxic gain-of-function by perturbing splicing factors in the nucleus, resulting in misregulation of alternative pre-mRNA splicing. Recent advances in basic and translational research and pharmacological approaches have provided clues for therapeutic intervention in DM. Herein, we review the RNA-dominant mechanism of DM and therapeutic approaches for targeting the toxic RNA.

Using digital technologies to engage with medical research: views of myotonic dystrophy patients in Japan

Background

As in other countries, the traditional doctor-patient relationship in the Japanese healthcare system has often been characterised as being of a paternalistic nature. However, in recent years there has been a gradual shift towards a more participatory-patient model in Japan. With advances in technology, the possibility to use digital technologies to improve patient interactions is growing and is in line with changing attitudes in the medical profession and society within Japan and elsewhere. The implementation of an online patient engagement platform is being considered by the Myotonic Dystrophy Registry of Japan. The aim of this exploratory study was to understand patients’ views and attitudes to using digital tools in patient registries and engagement with medical research in Japan, prior to implementation of the digital platform.

Methods

We conducted an exploratory, cross-sectional, self-completed questionnaire with a sample of myotonic dystrophy (MD) patients attending an Open Day at Osaka University, Japan. Patients were eligible for inclusion if they were 18 years or older, and were diagnosed with MD.

Results

A total of 68 patients and family members attended the Open Day and were invited to participate in the survey. Of those, 59 % submitted a completed questionnaire (n = 40). The survey showed that the majority of patients felt that they were not receiving the information they wanted from their clinicians, which included recent medical research findings and opportunities to participate in clinical trials, and 88 % of patients indicated they would be willing to engage with digital technologies to receive relevant medical information. Patients also expressed an interest in having control over when and how they received this information, as well as being informed of how their data is used and shared with other researchers.

Conclusion

Overall, the findings from this study suggest that there is scope to develop a digital platform to engage with patients so that they can receive information about medical care and research opportunities. While this study group is a small, self-selecting population, who suffer from a particular condition, the results suggest that there are interested populations within Japan that would appreciate enhanced communication and interaction with healthcare teams.

Electronic supplementary material

The online version of this article (doi:10.1186/s12910-016-0132-2) contains supplementary material, which is available to authorized users.

A case of non-dystrophic myotonia with concomitant mutations in the SCN4A and CLCN1 genes

Non-dystrophic myotonias are caused by mutations of either the skeletal muscle chloride (CLCN1) or sodium channel (SCN4A) gene. They exhibit several distinct phenotypes, including myotonia congenita, paramyotonia congenita and sodium channel myotonia, and a genotype-phenotype correlation has been established. However, there are atypical cases that do not fit with the standard classification. We report a case of 27-year-old male who had non-dystrophic myotonia with periodic paralysis and two heterozygous mutations, E950K in CLCN1 and F1290L in SCN4A. His mother, who exhibited myotonia without paralytic attack, only harbored E950K, and no mutations were identified in his asymptomatic father. Therefore, the E950K mutation was presumed to be pathogenic, although it was reported as an extremely rare genetic variant. The proband experienced paralytic attacks that lasted for weeks and were less likely to be caused by CLCN1 mutation alone. Functional analysis of the F1290L mutant channel heterologously expressed in cultured cells revealed enhanced activation inducing membrane hyperexcitability. We therefore propose that the two mutations had additive effects on membrane excitability that resulted in more prominent myotonia in the proband. Our case stresses the value of performing genetic analysis of both CLCN1 and SCN4A genes for myotonic patients with an atypical phenotype.

An elderly-onset limb girdle muscular dystrophy type 1B (LGMD1B) with pseudo-hypertrophy of paraspinal muscles

Mutations in LMNA, encoding A-type lamins, lead to diverse disorders, collectively called "laminopathies," which affect the striated muscle, cardiac muscle, adipose tissue, skin, peripheral nerve, and premature aging. We describe a patient with limb-girdle muscular dystrophy type 1B (LGMD1B) carrying a heterozygous p.Arg377His mutation in LMNA, in whom skeletal muscle symptom onset was at the age of 65 years. Her weakness started at the erector spinae muscles, which showed marked pseudo-hypertrophy even at the age of 72 years. Her first episode of syncope was at 44 years; however, aberrant cardiac conduction was not revealed until 60 years. The p.Arg377His mutation has been previously reported in several familial LMNA-associated myopathies, most of which showed muscle weakness before the 6th decade. This is the first report of pseudo-hypertrophy of paravertebral muscles in LMNA-associated myopathies. The pseudo-hypertrophy of paravertebral muscles and the elderly-onset of muscle weakness make this case unique and reportable.