Safety and efficacy of avalglucosidase alfa versus alglucosidase alfa in patients with late-onset Pompe disease (COMET): a phase 3, randomised, multicentre trial

BACKGROUND

Pompe disease is a rare, progressive neuromuscular disorder caused by deficiency of acid α-glucosidase (GAA) and accumulation of lysosomal glycogen. We assessed the safety and efficacy of avalglucosidase alfa, a recombinant human GAA enzyme replacement therapy specifically designed for enhanced mannose-6-phosphate-receptor targeting and enzyme uptake aimed at increased glycogen clearance, compared with the current approved standard of care, alglucosidase alfa, in patients with late-onset Pompe disease.

METHODS

We did a randomised, double-blind, phase 3 trial at 55 sites in 20 countries. We enrolled individuals (aged ≥3 years) with enzymatically confirmed late-onset Pompe disease who had never received treatment. We used a centralised treatment allocation system to randomly allocate participants to either avalglucosidase alfa or alglucosidase alfa. Participants and investigators were unaware of their treatment allocation. The primary outcome measure was change from baseline to week 49 in upright forced vital capacity percent (FVC%) predicted. We used a hierarchical fixed sequential testing strategy, whereby non-inferiority of avalglucosidase alfa compared with alglucosidase alfa was assessed first, with a non-inferiority margin of 1·1. If non-inferiority was seen, then superiority was tested with a 5% significance level. The key secondary objective was effect on functional endurance, measured by the 6-minute walk test (6MWT). Safety was assessed, including treatment-emergent adverse events and infusion-associated reactions. The modified intent-to-treat population was the primary analysis population for all efficacy analyses. The safety population was the analysis population for safety analyses. This trial is registered with ClinicalTrials.gov, NCT02782741. We report results of the 49-week primary analysis period.

FINDINGS

Between Nov 2, 2016, and March 29, 2019, 100 participants were randomly allocated avalglucosidase alfa (n=51) or alglucosidase alfa (n=49). Treatment with avalglucosidase alfa resulted in a least-squares mean improvement in upright FVC% predicted of 2·89% (SE 0·88) compared with 0·46% (0·93) with alglucosidase alfa at week 49 (difference 2·43% [95% CI -0·13 to 4·99]). Non-inferiority was shown because the lower bound of the 95% CI for the difference far exceeded the predefined non-inferiority margin but did not exclude 0 (p=0·0074). Superiority was not reached (p=0·063), so formal testing was stopped, as per the testing hierarchy. Improvements were also seen in the 6MWT with avalglucosidase alfa compared with alglucosidase alfa, with greater increases in distance covered (difference 30·01 m [95% CI 1·33 to 58·69]) and percent predicted (4·71% [0·25 to 9·17]). Treatment-emergent adverse events potentially related to treatment were reported in 23 (45%) of 51 participants in the avalglucosidase alfa group and in 24 (49%) of 49 in the alglucosidase alfa group, and infusion-associated reactions were reported in 13 (26%) participants in the avalglucosidase alfa group and 16 (33%) in the alglucosidase alfa group. Of the five trial withdrawals, all in the alglucosidase alfa group, four were due to adverse events, including two infusion-associated reactions. Serious treatment-emergent adverse events were reported in eight (16%) participants who received avalglucosidase alfa and in 12 (25%) who received alglucosidase alfa. One participant treated with alglucosidase alfa died because of acute myocardial infarction determined to be unrelated to treatment. Antidrug antibody responses were similar in both groups. High and persistent titres (≥12 800) and neutralising antibodies were more common with alglucosidase alfa (in 16 [33%] participants) than with avalglucosidase alfa (ten [20%]).

INTERPRETATION

We consider that this study provides evidence of clinically meaningful improvement with avalglucosidase alfa therapy over alglucosidase alfa in respiratory function, ambulation, and functional endurance, with no new safety signals reported. An open-label extended-treatment period is ongoing to confirm the long-term safety and efficacy of avalglucosidase alfa, with the aim for this therapy to become the new standard treatment in late-onset Pompe disease.

FUNDING

Sanofi Genzyme.

A Compound Heterozygous Pathogenic Variant in B4GALNT1 Is Associated With Axonal Charcot-Marie-Tooth Disease

Background and Purpose

Pathogenic variants in B4GALNT1 have been reported to cause hereditary spastic paraplegia 26. This study has revealed that a novel compound heterozygous pathogenic variant in B4GALNT1 is associated with axonal Charcot-Marie-Tooth disease (CMT).

Methods

Whole-exome sequencing (WES) was used to identify the causative factors and characterize the clinical features of a Korean family with sensorimotor polyneuropathy. Functional assessment of the mutant genes was performed using a motor neuron cell line.

Results

The WES revealed a compound heterozygous pathogenic variant (c.128dupC and c.451G>A) in B4GALNT1 as the causative of the present patient, a 53-year-old male who presented with axonal sensorimotor polyneuropathy and cognitive impairment without spasticity. The electrodiagnostic study showed axonal sensorimotor polyneuropathy. B4GALNT1 was critical to the proliferation of motor neuron cells. The compensation assay revealed that the pathogenic variants might affect the enzymatic activity of B4GALNT1.

Conclusions

This study is the first to identify a case of autosomal recessive axonal CMT associated with a compound heterozygous pathogenic variant in B4GALNT1. This finding expands the clinical and genetic spectra of peripheral neuropathy.

Clinical Features and Brain MRI Findings in Korean Patients with AGel Amyloidosis

PURPOSE

AGel amyloidosis is systemic amyloidosis caused by pathogenic variants in the GSN gene. In this study, we sought to characterize the clinical and brain magnetic resonance image (MRI) features of Korean patients with AGel amyloidosis.

MATERIALS AND METHODS

We examined 13 patients with AGel amyloidosis from three unrelated families. Brain MRIs were performed in eight patients and eight age- and sex-matched healthy controls. Therein, we analyzed gray and white matter content using voxel-based morphometry (VBM), tract-based spatial statistics (TBSS), and FreeSurfer.

RESULTS

The median age at examination was 73 (interquartile range: 64-76) years. The median age at onset of cutis laxa was 20 (interquartile range: 15-30) years. All patients over that age of 60 years had dysarthria, cutis laxa, dysphagia, and facial palsy. Two patients in their 30s had only mild cutis laxa. The median age at dysarthria onset was 66 (interquartile range: 63.5-70) years. Ophthalmoparesis was observed in three patients. No patient presented with muscle weakness of the limbs. Axial fluid-attenuated inversion recovery images of the brain showed no significant differences between the patient and control groups. Also, analysis of VBM, TBSS, and FreeSurfer revealed no significant differences in cortical thickness between patients and healthy controls at the corrected significance level.

CONCLUSION

Our study outlines the clinical manifestations of prominent bulbar palsy and early-onset cutis laxa in 13 Korean patients with AGel amyloidosis and confirms that AGel amyloidosis mainly affects the peripheral nervous system rather than the central nervous system.

Chitin Nanofiber-Reinforced Waterborne Polyurethane Nanocomposite Films with Enhanced Thermal and Mechanical Performance

To attain eco-friendly polyurethane composites with enhanced thermal and mechanical properties, in this study, a series of cationic waterborne polyurethane (cWPU) nanocomposite films reinforced with 1-50 wt% chitin nanofiber (ChNF) loadings was fabricated by a facile aqueous dispersion casting. The microstructure, thermal and mechanical properties of the nanocomposite films were investigated by considering the loading content and the interfacial interaction of ChNF in the cWPU matrix. For the purpose, a hard/soft segmented cWPU with an average particle size of ∼151 nm in aqueous dispersion was synthesized by using poly(tetramethylene glycol), isophorone diisocyanate, N-methyldiethanolamine, and 1,4-butanediol. The FT-IR spectra confirmed the existence of specific hydrogen-bonding interactions between hydroxyl/acetyl amine/ammonium groups of ChNFs and urethane/protonated amine groups of cWPU hard segments. Accordingly, the thermal decomposition temperatures of cWPU/ChNF nanocomposite films increased with increasing the ChNF content. In addition, the storage moduli of cWPU/ChNF nanocomposite films increased significantly with the increment of ChNF content up to ∼7 wt%, which stems from the restricted chain mobility of cWPU backbones composed of semicrystalline soft segments and hard segments interacting with ChNFs via multiple hydrogen-bonding interactions.

Two Cases of Facioscapulohumeral Muscular Dystrophy 2 in Korea

Facioscapulohumeral muscular dystrophy (FSHD) is an autosomal dominant muscular disorder characterized by weakness of facial, shoulder, abdominal, hip girdle, humeral, and anterior distal leg muscles, with descending progression from the face to the legs in an asymmetric pattern. In about 5% of patients with FSHD, no D4Z4 repeat contraction on chromosome 4q35 is observed; this disease entity is called FSHD2. FSHD2 is characterized by DNA hypomethylation on the 4q-subtelomeric macrosatellite repeat array D4Z4. In Korea, there have been no previous reports of FSHD2. We report the first two cases of FSHD2 in Korea, carrying c.3801delG and c.1580C>T mutations in the SMCHD1 gene, respectively. For rapid and accurate diagnosis of FSHD2, genetic analysis of the D4Z4 haplotype and methylation with next-generation sequencing are required.

Evaluating an In-House Cell-Based Assay for Detecting Antibodies Against Muscle-Specific Tyrosine Kinase in Myasthenia Gravis

Background and Purpose

Detecting antibodies against muscle-specific tyrosine kinase (MuSK Abs) is essential for diagnosing myasthenia gravis (MG). We applied an in-house cell-based assay (CBA) to detect MuSK Abs.

Methods

A stable cell line was generated using a lentiviral vector, which allowed the expression of MuSK tagged with green fluorescent protein in human embryonic kidney 293 (HEK293) cells. Serum and anti-human IgG antibody conjugated with red fluorescence were added. The presence of MuSK Abs was determined based on the fluorescence intensity and their colocalization in fluorescence microscopy. Totals of 218 serum samples collected from 177 patients with MG, 31 with other neuromuscular diseases, and 10 healthy controls were analyzed. The CBA results were compared with those of a radioimmunoprecipitation assay (RIPA) and an enzyme-linked immunosorbent assay (ELISA).

Results

The MuSK-HEK293 cell line stably expressed MuSK protein. The CBA detected MuSK Abs in 34 (19.2%) of 177 samples obtained from patients with MG and in none of the participants having other neuromuscular diseases or in the healthy controls. The clinical characteristics of the patients with MuSK MG determined based on the CBA were strongly correlated with known clinical features of MuSK MG. There was an almost perfect agreement between the results of the CBA and those of the RIPA (Cohen's kappa=0.880, p<0.001) and ELISA (Cohen's kappa=0.982, p<0.001).

Conclusions

The results of the in-house CBA showed excellent agreement with both the RIPA and ELISA. Our in-house CBA can be considered a reliable method for detecting MuSK Abs.

Colloidal MoS2 van der Waals Template for Growing Highly Uniform Nanomaterials

The van der Waals (vdW) structures of transition metal dichalcogenides (TMDCs) have been studied extensively owing to the excellent electronic, optoelectronic, and catalytic performance with the atomic-scale sharpness of the interfaces. In addition, the presence of substitution and redox reactions in the vdW gaps also provides huge potential to be employed as a nanoscale reactor. Herein, the vdW gap of colloidal MoS₂ is reported as a natural template for the formation of CoMo bimetallic oxide nanoparticles (BMONPs) with highly uniform size (∼4 nm), which resulted in further synthesis of the thin multiwalled carbon nanotubes with extremely narrow diameter distribution. This study not only pioneers a new application of TMDCs but also provides an efficient means to control the size of nanomaterials, which directly affect material properties.

Influences of cellulose nanofibril on microstructures and physical properties of waterborne polyurethane-based nanocomposite films

We herein report the effects of carboxymethylated cellulose nanofibril (c-CNF) on the microstructure, thermal and mechanical properties of waterborne polyurethane (WPU)-based nanocomposite films. For the purpose, an aqueous dispersion of hard/soft segmented WPU with a mean particle size of ∼169 nm was manufactured by using poly(propylene glycol), isophorone diisocyanate, 2,2-dimethylolpropionic acid and 1,4-butanediol. WPU nanocomposite films with 1-50 wt% c-CNF loadings were then manufactured via an efficient casting method. The FT-IR spectra revealed the presence of hydrogen-bonding interactions between the urethane/urea groups of WPU hard segments and the carboxymethyl/hydroxyl groups of c-CNF. Accordingly, the thermal and thermo-oxidative stability of the nanocomposite films was noticeably enhanced by the introduction of c-CNF. In addition, the storage moduli of the nanocomposite films as well as the glass transition temperatures of WPU hard segments increased significantly with increasing the c-CNF content by ∼7 wt% owing to the specific interactions between c-CNF and WPU hard segments.

Encapsulation of a Monolayer WSe2 Phototransistor with Hydrothermally Grown ZnO Nanorods

Transition metal dichalcogenides (TMDCs) are promising two-dimensional (2D) materials for realizing next-generation electronics and optoelectronics with attractive physical properties. However, monolayer TMDCs (^1LTMDCs) have various serious issues, such as instability under ambient conditions and low optical quantum yield from their extremely thin thickness of ∼0.7 nm. To overcome these issues, we constructed a hybrid structure (HS) by growing zinc oxide nanorods (ZnO NRs) on a monolayer tungsten diselenide (^1LWSe₂) using the hydrothermal method. Consequently, we confirmed not only enhanced photoluminescence of ^1LWSe₂ but also improved optoelectronic properties by fabricating the HS phototransistor. Through various investigations, we found that these phenomena were due to the antenna and p-type doping effects attributed to the ZnO NRs. In addition, we verified that the optoelectronic properties of ^1LTMDCs are maintained for 2 weeks in ambient condition through the sustainable encapsulation effect induced by our HS. This encapsulation method with inorganic materials is expected to be applied to improve the stability and performance of various emerging 2D material-based devices.

Clinical and Radiographic Characteristics of Neuro-Behçet's Disease in South Korea

Background and Purpose

Neurological involvement in Behçet's disease [neuro-Behçet's disease (NBD)] is uncommon, but it is worth investigating since it can cause substantial disability. However, difficulties exist in understanding the clinical features of NBD due to regional variations and the lack of studies utilizing well-established diagnostic criteria. We therefore analyzed the clinical features of patients with NBD based on the recent international consensus recommendation.

Methods

We retrospectively searched electronic databases for patients with Behçet's disease (BD) between 2000 and 2017, and reviewed their medical records. Based on the recent international consensus recommendation, patients with definite or probable NBD were included.

Results

Of 9,817 patients with the diagnosis code for BD, 1,682 (17.1%) visited the neurology clinic and 110 (1.1%) were classified as NBD. Ninety-eight patients exhibited parenchymal NBD and 12 exhibited nonparenchymal NBD. Their age at the onset of NBD was 37.6±10.6 years and the male-to-female ratio was 1.24:1. Brainstem syndrome (43.9%) was the most common condition in the 98 patients with parenchymal NBD, followed by multifocal (32.7%) and spinal cord (12.2%) syndromes. 72.4% exhibited acute NBD and 27.6% exhibited a progressive disease course. Frequent manifestations included pyramidal signs (52.0%), headache (45.9%), dysarthria (42.9%), and fever (31.6%). A frequent pattern in brain MRI was an upper brainstem lesion extending to the thalamus and basal ganglia.

Conclusions

Approximately 1% of the patients with suspected BD exhibited NBD. Neurologists must understand the clinical characteristics of NBD in order to perform the differential diagnosis and management of these patients.

Progression of GNE Myopathy Based on the Patient-Reported Outcome

Background and Purpose

GNE myopathy is a rare progressive myopathy caused by biallelic mutations in the GNE gene, and frequently accompanied by rimmed vacuoles in muscle pathology. The initial symptom of foot drop or hip-girdle weakness eventually spreads to all limbs over a period of decades. Recent advances in pathophysiologic research have facilitated therapeutic trials aimed at resolving the core biochemical defect. However, there remains unsettled heterogeneity in its natural course, which confounds the analysis of therapeutic outcomes. We performed the first large-scale study of Korean patients with GNE myopathy.

Methods

We gathered the genetic and clinical profiles of 44 Korean patients with genetically confirmed GNE myopathy. The clinical progression was estimated retrospectively based on a patient-reported questionnaire on the status of the functional joint sets and daily activities.

Results

The wrist and neck were the last joints to lose antigravity functionality irrespective of whether the weakness started from the ankle or hip. Two-thirds of the patients could walk either independently or with an aid. The order of losing daily activities could be sorted from standing to eating. Patients with limb-girdle phenotype showed an earlier age at onset than those with foot-drop onset. Patients with biallelic kinase domain mutations tended to progress more rapidly than those with epimerase and kinase domain mutations.

Conclusions

The reported data can guide the clinical management of GNE myopathy, as well as provide perspective to help the development of clinical trials.

Two Korean Families with Limb-Girdle Muscular Dystrophy Type 1D Associated with DNAJB6 Mutations

Limb-girdle muscular dystrophies (LGMD) are heterogeneous disorders with autosomal inheritance. Autosomal dominant LGMD mapped to 7q36.3 has been classified as LGMD type 1D (LGMD1D) in the Human Gene Nomenclature Committee Database. LGMD1D is characterized predominantly by limb-girdle weakness and may also show a bulbar symptom in some cases. In the past, the frequency of this disease was uncommon, and this disorder was mainly found in Europe and the United States. However, recently, this disorder has been reported in Asia, including Japan, Korea, and Taiwan. Here, we report on three LGMD1D patients, including one with a novel mutation in DNAJB6, c.298T>A. While two patients complained of limb-girdle weakness, as would be expected, one patient had distal weakness. They had various serum creatine kinase levels. Radiologic findings in one patient showed fatty degeneration and atrophy in the posterior part of distal muscles. Pathologic findings in one of the patients showed rimmed vacuoles. Although LGMD1D is still uncommon in Korea, we discovered three Korean patients with LGMD1D, including one novel mutation in DNAJB6, p.Phe100Ile (c.298T>A).

FAT1 Gene Alteration in Facioscapulohumeral Muscular Dystrophy Type 1

Facioscapulohumeral muscular dystrophy type 1 (FSHD1) is caused by contraction of the D4Z4 repeat array. Recent studies revealed that the FAT1 expression is associated with disease activity of FSHD, and the FAT1 alterations result in myopathy with a FSHD-like phenotype. We describe a 59-year-old woman with both contracted D4Z4 repeat units and a FAT1 mutation. Shoulder girdle muscle weakness developed at the age of 56 years, and was followed by proximal leg weakness. When we examined her at 59 years of age, she displayed asymmetric and predominant weakness of facial and proximal muscles. Muscle biopsy showed increased variation in fiber size and multifocal degenerating fibers with lymphocytic infiltration. Southern blot analysis revealed 8 D4Z4 repeat units, and targeted sequencing of modifier genes demonstrated the c.10331 A>G variant in the FAT1 gene. This FAT1 variant has previously been reported as pathogenic variant in a patient with FSHD-like phenotype. Our study is the first report of a FAT1 mutation in a FSHD1 patient, and suggests that FAT1 alterations might work as a genetic modifier.

Partial Conduction Block as an Early Nerve Conduction Finding in Neurolymphomatosis

BACKGROUND AND PURPOSE

Neurolymphomatosis is a rare manifestation of hematological malignancy and is characterized by direct infiltration of the peripheral nervous system. The objective of this study was to identify the clinical and electrophysiological features of neurolymphomatosis.

METHODS

We retrospectively analyzed the medical records of 13 patients with neurolymphomatosis. Seven (54%) of the patients were men, and the median age at symptom onset was 60.0 years.

RESULTS

The most common type of underlying malignancy was diffuse large B-cell lymphoma (69%). Twelve patients had painful asymmetric neuropathies. The median survival time after diagnosis was 7 months, and 12 patients died during the study period. Thirty-eight motor nerve conduction studies (NCSs) were performed in the affected nerves. Ten and 28 motor nerves were classified into the conduction-block and simple-axon-degeneration groups, respectively. The median time interval between symptom onset and the NCS was significantly shorter in the conduction-block group than in the simple-axon-degeneration group (p=0.032). However, no significant differences in the motor nerve conduction velocities, terminal latencies, and distal compound muscle action potential amplitudes were identified between the conduction-block and simple-axon-degeneration groups. The conduction-block group showed excessive temporal dispersion in only five of the ten NCSs (50%). Follow-up NCSs revealed that partial conduction blocks had changed into axonal degeneration patterns.

CONCLUSIONS

This is the first study to analyze the electrophysiological features of patients with neurolymphomatosis. Our findings showed that a partial conduction block is not rare and is an early nerve conduction abnormality in neurolymphomatosis.

Clinical and Pathologic Findings of Korean Patients with RYR1-Related Congenital Myopathy

Background and Purpose

This study was designed to investigate clinical and pathologic characteristics of five Korean patients with RYR1-related congenital myopathy (CM).

Methods

Five patients from unrelated families were diagnosed with RYR1-related CM via direct or targeted sequencing of RYR1. Their clinical, mutational, and pathologic findings were then analyzed.

Results

Seven different mutations were identified, including two novel mutations: c.5915A>T and c.12250C>T. All of the patients presented at infancy with proximal dominant weakness and delayed motor milestones. Other clinical findings were scoliosis in three patients, winged scapula in two, hip dislocation in one, and pectus excavatum in one. Ophthalmoplegia was observed in one patient with a novel recessive mutation. Two of three muscle specimens revealed a myopathic pattern with core.

Conclusions

We have identified a novel compound heterozygous RYR1 mutation and demonstrated clinical and pathologic findings in five Korean patients with RYR1-related CM.

Clinical Characteristics of Spinal Muscular Atrophy in Korea Confirmed by Genetic Analysis

The objective of this study was to review the clinical characteristics of patients with spinal muscular atrophy and to emphasize the importance of performing genetic mutational analysis at initial patient assessment. This is a single center oriented, retrospective, and descriptive study conducted in Seoul, South Korea. Genetic mutational analysis to detect the deletion of exon 7 of the SMN1 gene on chromosome 5q13 was performed by multiplex ligation-dependent probe amplification. Clinical features, electrodiagnostic study results, muscle biopsy results, and laboratory test results were reviewed from patient medical records. Of all 28 patients (15 males and 13 females), all showed bilateral symmetric proximal dominant weakness. Among them, 3 patients were classified as type I, 14 patients as type II, and 11 patients as type III. Twenty-five patients had scoliosis and eight of these patients received surgical treatment for scoliosis with improvement in clinical outcomes. Ventilator support was used in 15 patients. In terms of the diagnostic process, 15 patients had completed an electrodiagnostic study and muscle biopsy before genetic testing, and six of these patients were initially misdiagnosed with myopathy. Owing to the similar clinical features of SMA and congenital myopathy, an electrodiagnostic study and muscle biopsy could create confusion in the correct diagnosis in some cases. Therefore, it is recommended that genetic mutation analysis should be conducted along with an electrodiagnostic study or muscle biopsy in the diagnostic process for spinal muscular atrophy.

Clinical, Pathologic, and Genetic Features of Collagen VI-Related Myopathy in Korea

Background and Purpose

Mutations in collagen VI-related genes (COL6A1, COL6A2, and COL6A3) cause Bethlem myopathy (BM) and Ullrich congenital muscular dystrophy (UCMD). These were previously believed to be separate disease entities, but they are now both classified as collagen VI-related myopathies, which cover a broad clinical spectrum. We aimed to analyze the clinical, pathologic, and genetic characteristics of patients with collagen VI-related myopathy in Korea.

Methods

We reviewed the clinical, pathologic, and genetic features in 22 patients with collagen VI-related myopathy from 13 families, as confirmed by genetic analysis of collagen VI-related genes.

Results

The mean ages of the 22 patients at first symptom presentation and diagnosis were 4.5 and 24.9 years, respectively. Four patients in 4 families showed the phenotype of intermediate collagen VI-related myopathies (IM), 16 patients in 7 families had the BM phenotype, and 2 patients in 2 families presented with the typical UCMD phenotype. Based on genetic analysis, five patients (five families) comprising four with IM and one with typical UCMD had missense mutations in the triple-helical domain of COL6A1, and ten patients (four families) with BM showed exon-14-skipping mutations. Additionally, we found two novel mutations: c.956A>G (p.K319R) in COL6A1 and c.6221G>T (p.G2074V) in COL6A3.

Conclusions

Missense mutations in the triple-helical domain of COL6A1 are the most common mutations related to collagen VI-related myopathy in Korea. Patients with these mutations have a tendency toward an earlier disease onset and more severe progression compared to patients with other mutations.

Cortical Thickness and White Matter Integrity are Associated with CTG Expansion Size in Myotonic Dystrophy Type I

PURPOSE

Myotonic dystrophy type 1 (DM1) is characterized by progressive muscular weakness with symptoms caused by involvement of the brain. The aim of this study was to delineate global changes in cortical thickness and white matter integrity in patients with DM1, compared to age-matched healthy controls, and in brain areas highly correlated with CTG repeat size.

MATERIALS AND METHODS

Cortical thickness and white matter integrity were compared in nine adult DM1 patients and age matched healthy controls using T1-weighted and diffusion tensor imaging. The patients' intelligence quotient (IQ) and CTG repeat size were measured in each individual.

RESULTS

Cortical thickness was significantly reduced in the frontal, temporal, and occipital cortices, while tract-based spatial statistics showed decreased diffusion metrics in widespread areas, including the bilateral orbitofrontal, anterior frontal, insular, external capsule, and occipital cortices in DM1 patients, compared to controls. Additionally, thickness was negatively correlated with the number of CTG repeats in those areas. White matter integrity was negatively correlated with CTG repeats in the left entorhinal, anterior corona radiata, orbitofrontal, and lateral occipital areas. No statistically significant correlation was found between IQ scores and the size of CTG repeats.

CONCLUSION

Our results suggest that DM1 is associated with wide distributions of network changes in both gray and white matter. Some of areas related to cognition showed significant correlations with CTG repeats.

Early-Onset LMNA-Associated Muscular Dystrophy with Later Involvement of Contracture

Background and Purpose

The early diagnosis of LMNA-associated muscular dystrophy is important for preventing sudden arrest related to cardiac conduction block. However, diagnosing early-onset Emery-Dreifuss muscular dystrophy (EDMD) with later involvement of contracture and limb-girdle muscular dystrophy type 1B is often delayed due to heterogeneous clinical presentations. We aimed to determine the clinical features that contribute to a delayed diagnosis.

Methods

We reviewed four patients who were recently diagnosed with LMNA-associated muscular dystrophy by targeted exome sequencing and who were initially diagnosed with nonspecific or other types of muscular dystrophy.

Results

Certain clinical features such as delayed contracture involvement and calf hypertrophy were found to contribute to a delayed diagnosis. Muscle biopsies were not informative for the diagnosis in these patients.

Conclusions

Genetic testing of single or multiple genes is useful for confirming a diagnosis of LMNA-associated muscular dystrophy. Even EDMD patients could experience the later involvement of contracture, so clinicians should consider early genetic testing for patients with undiagnosed muscular dystrophy or laminopathy.

Pulmonary persistence of graphene nanoplatelets may disturb physiological and immunological homeostasis

Accumulated evidence suggests that chronic pulmonary accumulation of harmful particles cause adverse pulmonary and systemic health effects. In our previous study, most of the graphene nanoplatelet (GNP) remained in the lung until 28 days after a single instillation. In this study, we sought to evaluate the local and systemic health effect after a long pulmonary persistence of GNP. As expected, GNP remained in the lung on day 90 after a single intratracheal instillation (1.25, 2.5 and 5 mg kg^-1 ). In the lung exposed at the highest dose, the total number of cells and the percentage of lymphocytes significantly increased in the BAL fluid with an increase in both the number of GNP-engulfed macrophages and the percentage of apoptotic cells. A Th1-shifted immune response, the elevated chemokine secretion and the enhanced expression of cytoskeletal-related genes were observed. Additionally, the expression of natriuretic-related genes was noteworthy altered in the lungs. Moreover, the number of white blood cells (WBC) and the percentage of macrophages and neutrophils clearly increased in the blood of mice exposed to a 5-mg kg^-1 dose, whereas total protein, BUN and potassium levels significantly decreased. In conclusion, we suggest that the long persistence of GNP in the lung may cause adverse health effects by disturbing immunological- and physiological-homeostasis of our body. Copyright © 2016 John Wiley & Sons, Ltd.

The Epidemiology of Myasthenia Gravis in Korea

PURPOSE

An epidemiological study of myasthenia gravis (MG) has not been performed in Korea. The purpose of this study was to estimate the prevalence and incidence of MG in Korea.

MATERIALS AND METHODS

Health Insurance Review and Assessment (HIRA) data from 2010 to 2014 were searched for MG codes as defined by the International Classification of Diseases, 10th revision. After identifying MG cases, we estimated the prevalence and annual incidence of MG based on the HIRA database and Korean population data.

RESULTS

During the study period, 10138 MG cases were identified. The prevalence of MG was 10.42 cases per 100000 people in 2010 and this increased every year to 12.99 cases per 100000 people in 2014. The average incidence of MG between 2011 and 2014 was 0.69 cases per 100000 person-years. The prevalence and incidence were higher in the older (≥ 50 years) age group than in the younger (<50 years) age group [prevalence: 9.26 vs. 19.24 per 100000, relative risk 2.077, 95% confidence interval (CI) 1.976-2.183, p<0.001; incidence: 0.47 vs. 1.18 per 100000, relative risk 2.490, 95% CI 2.006-3.091, p<0.001].

CONCLUSION

This study was the first nationwide population-based epidemiological study of MG in Korea. The prevalence and incidence of MG were consistent with those of previous studies. We found an increase in the prevalence of MG and a predominance of elderly MG patients.

Clinical and Pathological Heterogeneity of Korean Patients with CAPN3 Mutations

PURPOSE

This study was designed to investigate the characteristics of Korean patients with calpainopathy.

MATERIALS AND METHODS

Thirteen patients from ten unrelated families were diagnosed with calpainopathy via direct or targeted sequencing of the CAPN3 gene. Clinical, mutational, and pathological spectra were then analyzed.

RESULTS

Nine different mutations, including four novel mutations (NM_000070: c.1524+1G>T, c.1789_1790inA, c.2184+1G>T, and c.2384C>T) were identified. The median age at symptom onset was 22 (interquartile range: 15-28). Common clinical findings were joint contracture in nine patients, winged scapula in four, and lordosis in one. However, we also found highly variable clinical features including early onset joint contractures, asymptomatic hyperCKemia, and heterogeneous clinical severity in three members of the same family. Four of nine muscle specimens revealed lobulated fibers, but three showed normal skeletal muscle histology.

CONCLUSION

We identified four novel CAPN3 mutations and demonstrated clinical and pathological heterogeneity in Korean patients with calpainopathy.

Whole-Body Muscle MRI in Patients with Hyperkalemic Periodic Paralysis Carrying the SCN4A Mutation T704M: Evidence for Chronic Progressive Myopathy with Selective Muscle Involvement

Background and Purpose

Hyperkalemic periodic paralysis (hyperKPP) is a muscle sodium-ion channelopathy characterized by recurrent paralytic attacks. A proportion of affected individuals develop fixed or chronic progressive weakness that results in significant disability. However, little is known about the pathology of hyperKPP-induced fixed weakness, including the pattern of muscle involvement. The aim of this study was to characterize the patterns of muscle involvement in hyperKPP by whole-body magnetic resonance imaging (MRI).

Methods

We performed whole-body muscle MRI in seven hyperKPP patients carrying the T704M mutation in the SCN4A skeletal sodium-channel gene. Muscle fat infiltration, suggestive of chronic progressive myopathy, was analyzed qualitatively using a grading system and was quantified by the two-point Dixon technique.

Results

Whole-body muscle MRI analysis revealed muscle atrophy and fatty infiltration in hyperKPP patients, especially in older individuals. Muscle involvement followed a selective pattern, primarily affecting the posterior compartment of the lower leg and anterior thigh muscles. The muscle fat fraction increased with patient age in the anterior thigh (r=0.669, p=0.009), in the deep posterior compartment of the lower leg (r=0.617, p=0.019), and in the superficial posterior compartment of the lower leg (r=0.777, p=0.001).

Conclusions

Our whole-body muscle MRI findings provide evidence for chronic progressive myopathy in hyperKPP patients. The reported data suggest that a selective pattern of muscle involvement-affecting the posterior compartment of the lower leg and the anterior thigh-is characteristic of chronic progressive myopathy in hyperKPP.

Clinical and Genetic Characterization of Female Dystrophinopathy

BACKGROUND AND PURPOSE

Duchenne and Becker muscular dystrophies are the most common X-linked recessive muscular dystrophies. Dystrophin gene mutations usually affect men, but reportedly 2.5-7.8% of women are affected and are classified as symptomatic carriers. The aim of this study was to clinically and genetically characterize symptomatic female dystrophinopathy carriers.

METHODS

The clinical and genetic data of 11 female dystrophinopathy carriers among 285 patients who underwent multiplex ligation-dependent probe amplification (MLPA) analysis for the dystrophin gene were reviewed. Women with muscle weakness and/or dilated cardiomyopathy were classified as symptomatic carriers, while subjects with high serum creatine kinase (CK) levels and/or minor myopathic signs such as muscle cramps and myalgia were classified as asymptomatic.

RESULTS

Twelve female carriers were identified, but 1 symptomatic carrier who also had Turner syndrome was excluded from the study. Of the 11 included female carriers, 4 were symptomatic and 7 were asymptomatic. The age at symptom onset in the symptomatic female carriers ranged from 15 to 31 years (mean, 30.6 years), and the age at diagnosis for asymptomatic carriers ranged from 4 to 38 years (mean, 24.5 years). Serum CK levels were markedly elevated (mean, 1,301 IU/mL) in three of the four (75%) symptomatic female carriers, and mildly elevated in three of the seven (42%) asymptomatic female carriers. Symptomatic female carriers typically presented with asymmetric bilateral leg weakness as the initial symptom, with aggravated symptoms after labor.

CONCLUSIONS

Female dystrophinopathy is not uncommon, and it is an important factor with respect to males with dystrophinopathy who may be born to such patients. Screening with MLPA is useful because it can aid in early diagnosis and appropriate management.

Characterization and phylogenetic analysis of the swine leukocyte antigen 3 gene from Korean native pigs

We investigated the phylogenetic relationships between pig breeds, compared the genetic similarity between humans and pigs, and provided basic genetic information on Korean native pigs (KNPs), using genetic variants of the swine leukocyte antigen 3 (SLA-3) gene. Primers were based on sequences from GenBank (accession Nos. AF464010 and AF464009). Polymerase chain reaction analysis amplified approximately 1727 bp of segments, which contained 1086 bp of coding regions and 641 bp of the 3'- and 5'-untranslated regions. Bacterial artificial chromosome clones of miniature pigs were used for sequencing the SLA-3 genomic region, which was 3114 bp in total length, including the coding (1086 bp) and non-coding (2028 bp) regions. Sequence analysis detected 53 single nucleotide polymorphisms (SNPs), based on a minor allele frequency greater than 0.01, which is low compared with other pig breeds, and the results suggest that there is low genetic variability in KNPs. Comparative analysis revealed that humans possess approximately three times more genetic variation than do pigs. Approximately 71% of SNPs in exons 2 and 3 were detected in KNPs, and exon 5 in humans is a highly polymorphic region. Newly identified sequences of SLA-3 using KNPs were submitted to GenBank (accession No. DQ992512-18). Cluster analysis revealed that KNPs were grouped according to three major alleles: SLA-3*0502 (DQ992518), SLA-3*0302 (DQ992513 and DQ992516), and SLA-3*0303 (DQ992512, DQ992514, DQ992515, and DQ992517). Alignments revealed that humans have a relatively close genetic relationship with pigs and chimpanzees. The information provided by this study may be useful in KNP management.

Molecular Genetic Diagnosis of a Bethlem Myopathy Family with an Autosomal-Dominant COL6A1 Mutation, as Evidenced by Exome Sequencing

Background

We describe herein the application of whole exome sequencing (WES) for the molecular genetic diagnosis of a large Korean family with dominantly inherited myopathy.

Case Report

The affected individuals presented with slowly progressive proximal weakness and ankle contracture. They were initially diagnosed with limb-girdle muscular dystrophy (LGMD) based on clinical and pathologic features. However, WES and subsequent capillary sequencing identified a pathogenic splicing-site mutation (c.1056+1G>A) in COL6A1, which was previously reported to be an underlying cause of Bethlem myopathy. After identification of the genetic cause of the disease, careful neurologic examination revealed subtle contracture of the interphalangeal joint in the affected members, which is a characteristic sign of Bethlem myopathy. Therefore, we revised the original diagnosis from LGMD to Bethlem myopathy.

Conclusions

This is the first report of identification of COL6A1-mediated Bethlem myopathy in Korea, and indicates the utility of WES for the diagnosis of muscular dystrophy.

Functional outcomes in Duchenne muscular dystrophy scoliosis: comparison of the differences between surgical and nonsurgical treatment

BACKGROUND

While most studies of Duchenne muscular dystrophy scoliosis focus on technical and radiographic indices, functional status is a more important factor to consider in the management of Duchenne muscular dystrophy. The objectives of the current study were to compare the pulmonary function, radiographic outcome, and functional recovery, with use of validated questionnaires, in surgically and nonsurgically treated patients with Duchenne muscular dystrophy who have scoliosis.

METHODS

Sixty-six patients (forty treated surgically and twenty-six treated nonsurgically) with a minimum follow-up of two years were included in this study. Forced vital capacity, radiographic parameters (the Cobb angle, lordosis, and pelvic obliquity), and functional status, according to the modified Rancho scale and manual muscle test, were measured preoperatively and at the time of the final follow-up. The Muscular Dystrophy Spine Questionnaire (MDSQ) was completed at the final follow-up evaluation.

RESULTS

Pulmonary function, functional scores (manual muscle test and modified Rancho scale), and radiographic measurements, except for lordosis, were similar for both groups at the time of the initial consultation (p > 0.05). At the time of the final follow-up, all radiographic parameters were significantly improved in the surgical group compared with the nonsurgical group. The mean score (and standard deviation) on the manual muscle test was not significantly different between the surgical and nonsurgical groups (23.2 ± 8.3 versus 22.8 ± 6.3; p = 0.828). The mean score on the modified Rancho scale also showed similar results in the groups (3.9 ± 0.3 and 4.04 ± 0.3, respectively; p = 0.088). The surgical group had higher mean MDSQ scores than the nonsurgical group (35.1 ± 14.7 and 26.9 ± 9.9, respectively; p = 0.008). Both groups showed a decrease in forced vital capacity at the time of the final follow-up, but the deterioration of forced vital capacity was significantly slower (p = 0.035) in the surgical group (268 ± 361 mL) than in the nonsurgical group (536 ± 323 mL).

CONCLUSIONS

Surgery in patients who had Duchenne muscular dystrophy with scoliosis improved function and decreased the rate of deterioration of forced vital capacity compared with patients treated conservatively. However, the muscle power and forced vital capacity decreased in both groups.

Metal–semiconductor transition like behavior of naphthalene-doped single wall carbon nanotube bundles

Naphthalene (N) or naphthalene-derivative (ND) adsorption-treatment evidently varies the electrical conductivity of single wall carbon nanotube (SWCNT) bundles over a wide temperature range due to a charge–transfer interaction. The adsorption treatment of SWCNTs with dinitronaphthalene molecules enhances the electrical conductivity of the SWCNT bundles by 50 times. The temperature dependence of the electrical conductivity of N- or ND-adsorbed SWCNT bundles having a superlattice structure suggests metal–semiconductor transition like behavior near 260 K. The ND-adsorbed SWCNT gives a maximum in the logarithm of electrical conductivity vs. T⁻¹ plot, which may occur after the change to a metallic state and be associated with a partial unravelling of the SWCNT bundle due to an evoked librational motion of the moieties of ND with elevation of the temperature.

Peroral endoscopic myotomy for treating achalasia in an animal model: a feasibility study

Background/Aims

Laparoscopic Heller myotomy with antireflux procedure is considered to be a standard treatment for achalasia. Recently, peroral endoscopic myotomy (POEM) was developed and performed on patients with achalasia. However, there is no report on POEM use in South Korea. The aim of this study was to evaluate the technical feasibility of POEM in a porcine model.

Methods

POEM was performed on two mini pigs. We performed upper endoscopy under general anesthesia. A submucosal tunnel was created and the circular muscle layer was incised using several knives. The mucosal entry was closed using resolution clips. We performed a follow-up endoscopy and sacrificed the pigs 2 weeks after the POEM. The myotomy site was evaluated grossly and histologically.

Results

POEM was successfully performed on the two mini pigs. No injuries to any abdominal or mediastinal structures occurred. Two weeks after the POEM, the esophageal mucosa healed without any endoscopic evidence of complications. Necropsy revealed that the circular muscle layer was completely lost and replaced with fibrotic tissue.

Conclusions

We found that POEM is a technically feasible method which can be performed on an animal model. However, to ensure safe use on patients with achalasia, further studies on technical methods and long-term follow-up examinations are required.

Is endoscopic ultrasound needed as an add-on test for gallstone diseases without choledocholithiasis on multidetector computed tomography?

BACKGROUND

Choledocholithiasis commonly occurs in patients with symptomatic cholelithiasis. Although the recently developed multidetector computed tomography (MDCT) scan enhances the ability to diagnose choledocholithiasis, this technique is considered to have some limitations for evaluating the common bile duct (CBD).

AIM

The purpose of this study was to evaluate the necessity for performing endoscopic ultrasound (EUS) as an add-on test to detect choledocholithiasis in patients who were diagnosed with gallstone disease without choledocholithiasis based on MDCT.

METHODS

Three hundred twenty patients with gallstone disease and no evidence of CBD stones according to MDCT underwent EUS between March 2006 and April 2011. If CBD stones were suspected based on the EUS results or clinical symptoms, a final diagnosis was obtained by endoscopic retrograde cholangiopancreatography (ERCP). The patients' medical records were retrospectively analyzed based on clinical symptoms, biochemical findings, and results of the imaging studies.

RESULTS

CBD stones were not detected with MDCT in 41 (12.8 %) out of 320 patients with gallstone disease. The causes for these discrepancies could be attributed to small stone size (n = 19, 46.3 %), isodensity (n = 18, 43.9 %), impacted stones (n = 1, 2.4 %), and misdiagnosis (n = 3, 7.3 %). If EUS were used as a triage tool, unnecessary diagnostic ERCP and its complications could be avoided for 245 (76.6 %) patients.

CONCLUSIONS

MDCT may not be a primary technique for detecting CBD stones. EUS should be performed instead as an add-on test to evaluate the CBD for patients with gallstone-related disease. In particular, EUS should be routinely recommended for patients with abnormal liver enzyme levels, pancreatitis, and dilated CBD.

Two cases of ileal dieulafoy lesion with massive hematochezia treated by single balloon enteroscopy

Ileal Dieulafoy lesion is an unusual vascular abnormality that can cause gastrointestinal bleeding. It can be associated with massive, life-threatening hemorrhage and requires urgent angiographic intervention or surgery. Ileal Dieulafoy lesion is hard to recognize due to inaccessibility and normal-appearing mucosa. With advances in endoscopy, aggressive diagnostic and therapeutic approaches including enteroscopy have recently been performed for small bowel bleeding. We report two cases of massive ileal Dieulafoy lesion bleeding diagnosed and treated successfully by single balloon enteroscopy with a review of the literature.

Self-assembled growth of nanocomposites consisting of TiO(2) nanopillars and Pb(Zr(0.52)Ti(0.48))O(3) thin films

We report for the first time the self-assembled growth of nanocomposites of 'TiO(2) nanopillars on Pb(Zr(0.52)Ti(0.48))O(3) (PZT) thin films' using a modified sol-gel processing. Both TiO(2) nanopillars and PZT thin films are simultaneously formed during the post-annealing process. The growth behaviours of TiO(2) nanopillars are controlled by adjusting the Ti excess amounts of PZT solutions and the post-annealing conditions. The self-assembled growth can be explained on the basis of the combined effects of five factors which can have influence during the annealing process: a Ti ion diffusion to the film surface, a phase separation of PZT and TiO(2), a void formation on the film surface, a Ti oxidation at the film surface under oxygen atmosphere, and a nanopillar growth on the film surface.

[A case of early bile duct cancer arising from villous adenoma in choledochal cyst]

Choledochal cyst is an uncommon premalignant anomaly. The morphology and pathogenesis of the premalignant lesion of cholangiocarcinoma arising from the choledochal cyst has not been well described. Herein, we report a rare case of bile duct adenoma arising from choledochal cyst with anomalous union of pancreaticobiliary duct (AUPBD). 50-year-old woman was admitted to our hospital with the complaint of epigastric pain. She had received common bile duct (CBD) exploration and choledocholithotomy and cholecystectomy 3 months earlier under the diagnosis of multiple CBD stones. Intraoperalive cholangiogram was not remarkable except CBD dilatation at that time. Endoscopic retrograde cholangiopancreatography revealed choledochal cyst with AUPBD and round filling defect which disappeared easily on the balloon cholaniogram. On magnetic resonance cholangiopancreatography, the filling defect was confirmed as 2 cm polypoid mass attached to the distal bile duct wall. At laparotomy, a soft whitish mass was palpable on the lower CBD. On histological examination, adenoma with focal carcinoma change arising from choledochal cyst was diagnosed.