Emery-Dreifuss Muscular Dystrophy Patients Research Articles

Echocardiographic Features of Cardiomyopathy in Emery-Dreifuss Muscular Dystrophy.

Background Emery-Dreifuss muscular dystrophy (EDMD) is a very rare type of muscular dystrophy characterized by musculoskeletal abnormalities accompanied by cardiac defects. Two most common genetic subtypes are EDMD1 due to EMD and EDMD2 caused by LMNA gene mutations. The aim of the study was to characterize and compare the cardiac morphology and function in the two main genetic subgroups of EDMD with the use of echocardiography. Methods 41 patients with EDMD (29 EDMD1 and 12 EDMD2) as well as 25 healthy controls were enrolled in our study. Transthoracic echo with the use of a prescribed protocol was performed. Results Highly statistically significant differences with regard to left ventricle (LV) volumes between the EDMD and the control group were found. 51% of EDMD patients had an enlarged left atrium and as many as 71% had an enlarged right atrium. The LV ejection fraction (LVEF) was significantly lower in EDMD patients than in the control group which corresponded also with a lower systolic velocity of the mitral annulus. 43% of EDMD patients had LVEF below the normal limit. Diastolic dysfunction was detected in 17% of EDMD patients. There were no significant differences between the two types of EDMD in terms of diameters and volumes of any chamber, as well as the systolic function of both left and right ventricles. Conclusions A significant number of EDMD patients present LV dilatation and different degrees of systolic dysfunction. Dilatation of the atria dominates over ventricle dilatation. We did not present any significant differences between EDMD1 and EDMD2 in terms of the morphology and the function of the heart.

A multistage sequencing strategy pinpoints novel candidate alleles for Emery-Dreifuss muscular dystrophy and supports gene misregulation as its pathomechanism.

BackgroundAs genome-wide approaches prove difficult with genetically heterogeneous orphan diseases, we developed a new approach to identify candidate genes. We applied this to Emery-Dreifuss muscular dystrophy (EDMD), characterised by early onset contractures, slowly progressive muscular wasting, and life-threatening heart conduction disturbances with wide intra- and inter-familial clinical variability. Roughly half of EDMD patients are linked to six genes encoding nuclear envelope proteins, but the disease mechanism remains unclear because the affected proteins function in both cell mechanics and genome regulation.MethodsA primer library was generated to test for mutations in 301 genes from four categories: (I) all known EDMD-linked genes; (II) genes mutated in related muscular dystrophies; (III) candidates generated by exome sequencing in five families; (IV) functional candidates — other muscle nuclear envelope proteins functioning in mechanical/genome processes affected in EDMD. This was used to sequence 56 unlinked patients with EDMD-like phenotype.FindingsTwenty-one patients could be clearly assigned: 18 with mutations in genes of similar muscular dystrophies; 3 with previously missed mutations in EDMD-linked genes. The other categories yielded novel candidate genes, most encoding nuclear envelope proteins with functions in gene regulation.InterpretationOur multi-pronged approach identified new disease alleles and many new candidate EDMD genes. Their known functions strongly argue the EDMD pathomechanism is from altered gene regulation and mechanotransduction due to connectivity of candidates from the nuclear envelope to the plasma membrane. This approach highlights the value of testing for related diseases using primer libraries and may be applied for other genetically heterogeneous orphan diseases.FundingThe Wellcome Trust, Muscular Dystrophy UK, Medical Research Council, European Community's Seventh Framework Programme “Integrated European –omics research project for diagnosis and therapy in rare neuromuscular and neurodegenerative diseases (NEUROMICS)”.

Dysfunctional lamins as mediators of oxidative stress in Emery-Dreifuss muscular dystrophy.

Deficit of lamin A/C or emerin causes genetically transmitted Emery-Dreifuss muscular dystrophy (EDMD). As lamins are considered to be mediators of oxidative stress, the antioxidant/oxidant status was examined. The total oxidant/antioxidant status in serum was examined in 29 cases of Emery-Dreifuss muscular dystrophy. The study included 12 autosomal-dominant laminopathies (AD-EDMD), 17 X-linked emerinopathies (X-EDMD) and 20 age-matched normal subjects. Total oxidant status (TOS) was reduced in all cases, and the total antioxidant capacity (TAC) was found to be decreased in the majority of the patients (in 82.8%). A relationship between TOS level and disease progression was noted. No correlation between TOS/TAC level and cardiological or neurological parameters was detected. The results of the study indicate disturbances of redox balance in EDMD patients. Determination of TOS/TAC might help to assess the progress of the disease and the potential effectiveness of antioxidant therapy.

Immunohistochemistry on a panel of Emery–Dreifuss muscular dystrophy samples reveals nuclear envelope proteins as inconsistent markers for pathology

Reports of aberrant distribution for some nuclear envelope proteins in cells expressing a few Emery–Dreifuss muscular dystrophy mutations raised the possibility that such protein redistribution could underlie pathology and/or be diagnostic. However, this disorder is linked to 8 different genes encoding nuclear envelope proteins, raising the question of whether a particular protein is most relevant. Therefore, myoblast/fibroblast cultures from biopsy and tissue sections from a panel of nine Emery–Dreifuss muscular dystrophy patients (4 male, 5 female) including those carrying emerin and FHL1 (X-linked) and several lamin A (autosomal dominant) mutations were stained for the proteins linked to the disorder. As tissue-specific nuclear envelope proteins have been postulated to mediate the tissue-specific pathologies of different nuclear envelopathies, patient samples were also stained for several muscle-specific nuclear membrane proteins. Although linked proteins nesprin 1 and SUN2 and muscle-specific proteins NET5/Samp1 and Tmem214 yielded aberrant distributions in individual patient cells, none exhibited defects through the larger patient panel. Muscle-specific Tmem38A normally appeared in both the nuclear envelope and sarcoplasmic reticulum, but most patient samples exhibited a moderate redistribution favouring the sarcoplasmic reticulum. The absence of striking uniform defects in nuclear envelope protein distribution indicates that such staining will be unavailing for general diagnostics, though it remains possible that specific mutations exhibiting protein distribution defects might reflect a particular clinical variant. These findings further argue that multiple pathways can lead to the generally similar pathologies of this disorder while at the same time the different cellular phenotypes observed possibly may help explain the considerable clinical variation of EDMD.

FHL1B Interacts with Lamin A/C andEmerin at the Nuclear Lamina andisMisregulated in Emery-Dreifuss Muscular Dystrophy.

Emery-Dreifuss muscular dystrophy (EDMD) is associated with mutations in EMD and LMNA genes, encoding for the nuclear envelope proteins emerin and lamin A/C, indicating that EDMD is anuclear envelope disease. We recently reported mutations in FHL1 gene in X-linked EDMD. FHL1 encodes FHL1A, and the two minor isoforms FHL1B and FHL1C. So far, none have been described at the nuclear envelope. To gain insight into the pathophysiology of EDMD, we focused our attention on the poorly characterized FHL1B isoform. The amount and the localisation of FHL1B were evaluated in control and diseased human primary myoblasts using immunofluorescence and western blotting. We found that in addition to acytoplasmic localization, this isoform strongly accumulated at the nuclear envelope of primary human myoblasts, like but independently of lamin A/C and emerin. During myoblast differentiation, we observed amajor reduction of FHL1B protein expression, especially in the nucleus. Interestingly, we found elevated FHL1B expression level in myoblasts from an FHL1-related EDMD patient where the FHL1 mutation only affects FHL1A, as well as in myoblasts from an LMNA-related EDMD patient. Altogether, the specific localization of FHL1B and its modulation in disease-patient's myoblasts confirmed FHL1-related EDMD as anuclear envelope disease.

Cardiac pacing in 21 patients with Emery-Dreifuss muscular dystrophy: a single-centre study with a 39-year follow-up.

Emery-Dreifuss muscular dystrophy (EDMD) is a genetic condition associated with cardiac arrhythmias. The patients typically develop early, asymptomatic bradyarrhythmia, which may lead to sudden death, preventable with a cardiac implantable electronic device (CIED). EDMD may be characterised by atrial electrical silence. Intra-operative electrophysiological evaluation of the myocardium helps ultimately determine the true nature of the disorder and select an appropriate CIED. To analyse permanent electrotherapy procedures in EDMD patients: atrial pacing limitations that stem from the electrophysiological properties of the myocardium and long-term follow-up of implanted devices. A total of 21 EDMD patients (mean age 29 ± 9 years) with a CIED implanted (1976-2014) due to bradyarrhythmia were included in the study. The implantation procedures and factors determining the CIED type selection were analysed. CIEDs were implanted in five women and in 16 men with EDMD types 1 and 2 (mean follow-up: 11 ± 8 years). Intra-operatively assessed atrial electrophysiology resulted in changing the planned CIED type during the procedure in three men with EDMD type 1. Eventually, we implanted: eight DDD, one VDD, 11 VVI, and one CD-DR device, with four of the patients' devices switched later from DDD to VVI mode in response to electrophysiological changes in the atria. Intra-operative assessment of atrial electrophysiological properties resulted in changing the planned DDD mode for VVI in 19% of patients with EDMD type 1. Progression of the underlying disease over a 39-year follow-up resulted in a later change of the initially selected pacing mode from DDD to VVI in 40% of cases.

AB091. Analysis of LA2 as a functional candidate gene for Emery Dreifuss muscular dystrophy and dilated cardiomyopathy.

Laminopathies are rare genetic disorders caused by mutations in genes encoding lamins or lamin-interacting proteins. LMNA, EDM and to a lower measure the Nesprin genes have been associated with Emery Dreifuss muscular dystrophy (EDMD), characterized by contractures of the Achilles tendons, progressive skeletal muscle weakness and heart rhythm disturbances leading to dilated cardiomyopathy (DCM) and sudden cardiac death. Since ~60% EDMD patients are not associated to known genes, we used a functional candidate-gene approach to identify additional EDMD disease genes. Based on reported interactions of lamina associated polypeptide 2 (LAP2) with nucleoplasmic lamin A/C and the association of the LAP2alpha isoform to DCM (Matthew R.G Taylor et al. 2005), 111 EDMD and 87 DCM patients were investigated for DNA variations in LAP (encoding six LAP2 isoforms) using heteroduplex analysis and direct sequencing. Among ten variations found, four changes—p.P426L (c.1481C>T) in LAP2alpha, p.D271E (c.1054T>G) in LAP2beta, and p.V423L (c.1058G>C) and p.M381I (c.1387 G>A) in LAP2gamma—were unique for EDMD patients, but segregation analysis indicated only p.P426L LAP2alpha as a mutation potentially associated to EDMD. P426L-LAP2 alpha localized to the nucleoplasm in skin fibroblasts, like wild-type protein and did not affect the loalization of lamin A. However, in mutant fibroblast cultures phosphorylated retinoblastoma protein (Rb) levels were reduced compared to wild-type cultures, sugesting that the mutated protein may affect cell cycle progression in agreement with previous studies implicating LAP2alpha-lamin A in Rb-mediated cell cycle control. The present study shows that LAP2alpha mutations might add to the pathology of EDMD in ~1% of EDMD patients.

Tissue inhibitors of matrix metalloproteinases in serum are cardiac biomarkers in Emery-Dreifuss muscular dystrophy

Tissue inhibitors of matrix metalloproteinases (TIMPs) are known to be involved in cardiovascular diseases. Hitherto, they have not been examined in dilated cardiomyopathy in the course of Emery-Dreifuss muscular dystrophy (EDMD). To define TIMPs in serum because they might help in defining cardiac dysfunction at the early cardiological stages of this disease and detect preclinical stages of cardiomyopathy. Twenty-five EDMD patients connected with lamin A/C (AD-EDMD) or emerin (X-EDMD) deficiency and 20 healthy age-matched controls were examined. The serum levels of the tissue inhibitors TIMP-1, -2, -3 were quantified using the ELISA sandwich immunoassay procedure with appropriate antibodies. Serum levels of TIMP-1 were normal in autosomal AD-EDMD and increased in the majority of X-linked EDMD. The level of TIMP-2 was decreased in 25%/21% of AD-EDMD/X-EDMD cases. TIMP-3 serum level was significantly reduced in all the examined patients. Receiver operating curves indicated that in terms of sensitivity and specificity characteristics the performance of TIMP-3 (less that of TIMP-2) makes them the best markers of cardiac involvement among the examined TIMPs. Evidence shows that the levels of TIMP-3, and in some cases also TIMP-2, are decreased in EDMD. The decrease might be associated with an adverse effect on matrix metalloproteinases and remodelling of the myocardial matrix. The specific decrease of TIMP-3 indicates that this biomarker might help in early detection of cardiac involvement in EDMD. Up-regulation of TIMP-1 in the majority of patients with X-EDMD indicates increased myocardial extracellular matrix turnover, early onset of tissue remodelling, and may contribute to arrhythmia, frequently occurring in this form of the disease.

Professional activity of Emery-Dreifuss muscular dystrophy patients in Poland.

Emery-Dreifuss muscular dystrophy (EDMD) is a very rare genetic disorder affecting skeletal and heart muscles. The aim of this study was to identify factors which might influence the ability to work in EDMD patients in Poland. The study included 24 patients suffering from either of the two EDMD forms: 17 with emerinopathy (EDMD1; EDMD caused by mutations in the emerin gene) and 7 with laminopathy (EDMD2; EDMD caused by the lamin A/C gene mutations). After clinical evaluation of EDMD course, study participants were questioned about their education, current and former employment, and disability certificates and pensions. 54% of the study participants were employed, and 90% of them had job position corresponding to their education. Undertaking work did not correlate with the level of physical performance or disease complication, but it revealed statistically significant correlation with a higher level of education (p = 0.015). Only 23% of professionally active patients were employed in a sheltered workplace. Disability certificate was granted to all EDMD2 and to 90% of EDMD1 patients. All EDMD2 and 50% of EDMD1 patients received a disability pension, which reflects more severe course of EDMD2. Higher level of education increased the chance of employment, even if significant disability was present. Therefore, I hypothesize that advice on education and job counseling should be applied as early as possible after the diagnosis of EDMD.

Skeletal Muscle Biopsy Analysis in Reducing Body Myopathy and Other FHL1-Related Disorders

FHL1 mutations have been associated with various disorders that include reducing body myopathy (RBM), Emery-Dreifuss-like muscular dystrophy, isolated hypertrophic cardiomyopathy, and some overlapping conditions. We report a detailed histochemical, immunohistochemical, electron microscopic, and immunoelectron microscopic analyses of muscle biopsies from 18 patients carrying mutations in FHL1: 14 RBM patients (Group 1), 3 Emery-Dreifuss muscular dystrophy patients (Group 2), and 1 patient with hypertrophic cardiomyopathy and muscular hypertrophy (Group 2). Group 1 muscle biopsies consistently showed RBs associated with cytoplasmic bodies. The RBs showed prominent FHL1 immunoreactivity whereas desmin, αB-crystallin, and myotilin immunoreactivity surrounded RBs. By electron microscopy, RBs were composed of electron-dense tubulofilamentous material that seemed to spread progressively between the myofibrils and around myonuclei. By immunoelectron microscopy, FHL1 protein was found exclusively inside RBs. Group 2 biopsies showed mild dystrophic abnormalities without RBs; only minor nonspecific myofibrillar abnormalities were observed under electron microscopy. Molecular analysis revealed missense mutations in the second FHL1 LIM domain in Group 1 patients and ins/del or missense mutations within the fourth FHL1 LIM domain in Group 2 patients. Our findings expand the morphologic features of RBM, clearly demonstrate the localization of FHL1 in RBs, and further illustrate major morphologic differences among different FHL1-related myopathies.

Left ventricular hypertrophy caused by a novel nonsense mutation in FHL1

Emery Dreifuss muscular dystrophy (EDMD) is a hereditary muscular disorder, characterized by contractures, progressive muscular wasting and cardiac involvement. The majority of EDMD patients harbor mutations in the lamin A/C (LMNA) and emerin (STA) genes. Emerging data implicate mutations in FHL1 (four and a half LIM protein 1) gene, located in chromosome Xq26, in EDMD pathogenesis. FHL1 is mainly expressed in striated and cardiac muscle, and plays an important role in sarcomeric protein synthesis, maintenance of cellular integrity, intracellular signaling and genetic transcription pathways. We report the identification of a novel nonsense mutation in FHL1 gene, associated with left ventricular hypertrophy and a family history of stroke and sudden cardiac death. The management implications of this diagnosis are also discussed.

080: Long-term outcomes after heart transplantation for Emery-Dreifuss muscular dystrophy

Emery-Dreifuss muscular dystrophy (EDMD) is an hereditary syndrome related to mutations in lamin A/C gene (LMNA) and is characterised by severe dilated cardiomyopathy, mostly slight peripheral muscular dystrophy, supra-ventricular arrhythmia and atrio-ventricular (AV) block. Transplantation for EDMD is rarely reported in the ISHLT registry. We aim to study outcomes after heart transplantation (HTx) for end-stage heart failure in twelve EDMD patients. 12 cases of HTx performed for EDMD confirmed by genetic analysis in a single institution between 1997 and 2011 were compared to 12 patients age, sex and year of transplantation matched. Survival curves were analysed by Kaplan-Meier method. Before transplantation, EDMD patients had similar age (56 vs 57 yo, p=0,81), sex ratio (42% male), pre-transplantation NYHA functional class III (p=0,207), left ventricular ejection fraction (LVEF=33% vs 32%, p=0,89), higher rate of supra-ventricular arrythmia (100% vs 45%, p=0,002) and AV block (58% vs 12.5%, p=0,042) compared to non-EDMD. After HTx, NYHA functional class was similar (I, p=1,00), LVEF (72+/-5,91% vs 69+/-11,3%, p=0,49), rejection rate (19+/-3,8% vs 40+/-8,2% by year, p=0,45), infection rate (14% vs 6% by year, p=0,087), renal function (eGFR=89+/-49 vs 66+/-37 ml/min, p=0,22) were similar after HTx in EDMD and non-EDMD group. Survival rate at 1 year, 2 years, 5 years were not significantly different (respectively 91.6%, 90.9%, 81.5% versus 100%, 100%, 100% p=0,146). 42% EDMD patients had slight muscular dysfunction, compatible with good quality of life. Despite reluctance for heart transplantation in end-stage HF patients with EDMD, long term outcomes are similar to non EDMD patients at 1,2 and 5-year follow-up in our institution.

G.P.120 FHL1-related Reducing Body Myopathy and Emery–Dreifuss muscular dystrophy: A comparative histoenzymological, immunohistochemical and ultrastructural study

<h2>Abstract</h2> FHL1-related myopathies are rare disorders that recently emerged and include reducing body myopathy (RBM) a congenital disorder defined by the presence of cytoplasmic inclusions revealed by menadione-NBT staining, and Emery–Dreifuss muscular dystrophy (EDMD) characterized by early joint contractures, muscular dystrophy and cardiac involvement with arrhythmias. We report the muscle biopsy features in a series of 13 patients suffering from RBM (9) and EDMD (4) with mutations in FHL1 gene, emphasizing unusual morphological characteristics. A summary of the clinical examination was performed. Muscle specimens were processed for histoenzymological, immunohistochemical and ultrastructural analysis. Molecular analysis was accomplished by sequencing the coding regions of FHL1 gene. Muscle biopsies from RBM patients showed marked variation of fiber size, increased number of internal nuclei, fibro-fatty tissue proliferation and type I fiber predominance. A sectorial distribution of lesions was observed. Several fibers contained large inclusions strongly reacting with menadione-NBT. Desmin, alphaB-crystallin and myotilin immunoreactivity was observed surrounding RB but not within them. At the ultrastructural level, reducing bodies and cytoplasmic bodies were observed in all muscle biopsies. Furthermore a dense granular material was usually found in the subsarcolemmal region and between the myofibrils; surprisingly this was frequently seen around the myonuclei and associated to cytoplasmic bodies. By contrast, no reducing bodies were found in EDMD and the lesions were minimal. Molecular analysis revealed missense mutations in the 2nd FHL1 LIM domain for the RBM patients and ins/del or missense mutations affecting the 4th FHL1 LIM domain for EDMD patients. Our findings expand the morphological features of reducing body myopathy and further illustrate major morphological differences between patients carrying mutations in the 2nd or in the 4th LIM domain of FHL1.

Increased dispersion of ventricular repolarization in emery dreifuss muscular dystrophy patients

SummaryBackgroundSudden cardiac death (SCD) is common in patients with Emery-Dreifuss muscular dystrophy (EDMD) and is attributed to the development of life-threatening arrhythmias that occur in the presence of normal left ventricular systolic function. Heterogeneity of ventricular repolarization is considered to provide an electrophysiological substrate for malignant arrhythmias. QTc dispersion (QTc-D) and JTc dispersion (JTc-D) are electrocardiographic parameters indicative of heterogeneity of ventricular repolarization. The aim of our study was to evaluate the heterogeneity of ventricular repolarization in patients with Emery-Dreifuss muscular dystrophy with preserved systolic and diastolic cardiac functionMaterial/MethodsThe study involved 36 EDMD patients (age 20±12, 26 M) and 36 healthy subjects used as controls, matched for age and sex. Heart rate, QRS duration, maximum and minimum QT and JT interval, QTc-D and JTc-D measurements were performed.ResultsCompared to the healthy control group, the EDMD group presented increased values of QTc-D (82.7±44.2 vs. 53.1±13.7; P=0,003) and JTc-D (73.6±32.3 vs. 60.4±11.1 ms; P=0.001). No correlation between QTc dispersion and ejection fraction (R=0.2, P=0.3) was found.ConclusionsOur study showed a significant increase of QTc-D and JTc-D in Emery-Dreifuss muscular dystrophy patients with preserved systolic and diastolic cardiac function.

Natriuretic Peptides Assessment in Dilated Cardiomyopathy in Patients with Emery-Dreifuss Muscular Dystrophy

Introduction: Levels of natriuretic peptides in blood are often tested for as screening for heart disease and their progress assessed. Dilated cardiomyopathy (DCM) with conduction disturbances is one of the leading serious manifestations in genetically transmitted Emery-Dreifuss muscular dystrophy (EDMD). However, the potential significance of and variability to brain-natriuretic peptides (BNP) and atrial-natriuretic peptides (ANP) in this disease has not been tested hitherto. It seemed worth considering whether estimation of natriuretic peptides might help in defining cardiac dysfunction in the early stages of the disease, prior to the appearance of echocardiographic changes. This is perceived especially important in cardiologically asymptomatic patients, who are still at risk of cardiac sudden death. Patients and Methods: Serum levels of BNP, NT-proBNP, ANP and NT-proANP were quantified by ELISA sandwich immunoassay in 25 EDMD patients (10 autosomal-dominant AD-EDMD, 15 X-linked EDMD), 8 X-EDMD carriers, 9 patients with dystrophinopathy as disease controls, and 20 age-matched healthy controls. Results: Serum levels of BNP, NT-pro-BNP, ANP, and NT-proANP were elevated in the blood of about 50% of patients with both the AD-EDMD and the X-EDMD form. Values were distributed from normal through to highly elevated. In the X-EDMD group there was a marked increase in the ANP and NT-proANP values. The X-EDMD group also manifested a correlation between level of atrial natriuretic peptides, echocardiographic parameters and severity of cardiac symptoms. Conclusions: The presented results indicate that assessment of circulating natriuretic peptides is of limited value in identifying cardiac involvement in EDMD. However, when included to the panel of other cardiologic biomarkers the estimation of natriuretic peptides may offer additional information in respect of proper diagnosis, prognosis, monitoring of appropriate treatment, prediction of outcome. and help to prevent cardiac decompensation and sudden death.

The LINC complex and human disease

The LINC (linker of nucleoskeleton and cytoskeleton) complex is a proposed mechanical link tethering the nucleo- and cyto-skeleton via the NE (nuclear envelope). The LINC components emerin, lamin A/C, SUN1, SUN2, nesprin-1 and nesprin-2 interact with each other at the NE and also with other binding partners including actin filaments and B-type lamins. Besides the mechanostructural functions, the LINC complex is also involved in signalling pathways and gene regulation. Emerin was the first LINC component associated with a human disease, namely EDMD (Emery-Dreifuss muscular dystrophy). Later on, other components of the LINC complex, such as lamins A/C and small isoforms of nesprin-1 and nesprin-2, were found to be associated with EDMD, reflecting a genetic heterogeneity that has not been resolved so far. Only approximately 46% of the EDMD patients can be linked to genes of LINC and non-LINC components, pointing to further genes involved in the pathology of EDMD. Obvious candidates are the LINC proteins SUN1 and SUN2. Recently, screening of binding partners of LINC components as candidates identified LUMA (TMEM43), encoding a binding partner of emerin and lamins, as a gene involved in atypical EDMD. Nevertheless, such mutations contribute only to a very small fraction of EDMD patients. EDMD-causing mutations in STA/EMD (encoding emerin) that disrupt emerin binding to Btf (Bcl-2-associated transcription factor), GCL (germ cell-less) and BAF (barrier to autointegration factor) provide the first glimpses into LINC being involved in gene regulation and thus opening new avenues for functional studies. Thus the association of LINC with human disease provides tools for understanding its functions within the cell.

Osteopontin – a fibrosis-related marker – in dilated cardiomyopathy in patients with Emery-Dreifuss muscular dystrophy

Background: As osteopontin (OPN) may be assumed to have diagnostic/prognostic value in heart diseases, it is worth assessing whether it is also involved in the pathogenesis and can be applied in the diagnosis of the dilated cardiomyopathy (DCM) in Emery-Dreifuss muscular dystrophy (EDMD). Methods: Serum levels of osteopontin were quantified by means of sandwich immunoassay in 25 EDMD patients (10 laminopathies AD-EDMD and 15 emerinopathies – X-EDMD), eight carriers of X-EDMD, nine disease controls (patients with dystrophinopathy) and 20 age-matched healthy controls. Results: The levels of circulating OPN were elevated in all AD-EDMD and X-linked EDMD patients, as well as in X-EDMD carriers and patients suffering progressive muscular dystrophy. There was no correlation between the osteopontin level and different cardiac parameters, including left-ventricular end-diastolic diameter, left atrial diameter, the left ventricular ejection fraction and the CK-MB level. There was a slight negative correlation with the ages of the patients. Conclusions: The presented results indicate that assessments of circulating OPN levels may help to identify EDMD patients at risk of dilated cardiomyopathy and might be therefore included among the set of biomarkers referred to with a view to appropriate early cardiologic diagnosis and therapy being commenced with in time.

Circulating tenascin-C levels in patients with dilated cardiomyopathy in the course of Emery-Dreifuss muscular dystrophy

BackgroundTenascin-C (TN-C), an extracellular matrix glycoprotein, is of diagnostic and prognostic value in different heart diseases. One such dilated cardiomyopathy (DCM) with conduction disturbances is one of the most serious manifestations in Emery-Dreifuss muscular dystrophy (EDMD). Herein we therefore detail work to evaluate the potential significance of circulating TN-C in patients with EDMD, speculating that it may define the cardiac dysfunction, especially in patients who may be cardiac asymptomatic, but still be at risk of sudden death. Material and methodSerum levels of TN-C were quantified by sandwich immunoassay ELISA in 25 EDMD patients (10 with laminopathy—AD-EDMD and 15 with emerinopathy—X-EDMD), 8 X-EDMD carriers, 9 disease controls (patients with dystrophinopathy), and 15 age-matched healthy controls. Fourteen of the EDMD patients had repeated TN-C examinations after 3 to 7years. ResultsThe levels of circulating TN-C were elevated in AD-EDMD and X-EDMD patients, as well as in some X-EDMD carriers, and patients with dystrophinopathy. The correlation between the TN-C level and left end-systolic ventricle diameter (LVDD) was significant in X-EDMD, while those with left atrium diameter (LAD) and the ejection fraction (EF) were not. In “follow-up” studies TN-C levels were not found to change over time in AD-EDMD, while rising in X-EDMD. ConclusionsThe presented results indicate that assessments of circulating TN-C levels may help to identify EDMD patients at risk of dilated cardiomyopathy. TN-C might therefore be considered a candidate for a new biomarker, useful in detecting of cardiomyopathy and in further monitoring of the DCM therapy in patients with EDMD.

Novel LMNA mutations in patients with Emery-Dreifuss muscular dystrophy and functional characterization of four LMNA mutations

Mutations in LMNA cause a variety of diseases affecting striated muscle including autosomal Emery-Dreifuss muscular dystrophy (EDMD), LMNA-associated congenital muscular dystrophy (L-CMD), and limb-girdle muscular dystrophy type 1B (LGMD1B). Here, we describe novel and recurrent LMNA mutations identified in 50 patients from the United States and Canada, which is the first report of the distribution of LMNA mutations from a large cohort outside Europe. This augments the number of LMNA mutations known to cause EDMD by 16.5%, equating to an increase of 5.9% in the total known LMNA mutations. Eight patients presented with either p.R249W/Q or p.E358K mutations and an early onset EDMD phenotype: two mutations recently associated with L-CMD. Importantly, 15 mutations are novel and include eight missense mutations (p.R189P, p.F206L, p.S268P, p.S295P, p.E361K, p.G449D, p.L454P, and p.W467R), three splice site mutations (c.IVS4 + 1G>A, c.IVS6 - 2A>G, and c.IVS8 + 1G>A), one duplication/in frame insertion (p.R190dup), one deletion (p.Q355del), and two silent mutations (p.R119R and p.K270K). Analysis of 4 of our lamin A mutations showed that some caused nuclear deformations and lamin B redistribution in a mutation specific manner. Together, this study significantly augments the number of EDMD patients on the database and describes 15 novel mutations that underlie EDMD, which will contribute to establishing genotype-phenotype correlations.

Ventricular Arrhythmia in X-linked Emery-Dreifuss Muscular Dystrophy: A Lesson from an Autopsy Case

Emery-Dreifuss muscular dystrophy (EDMD) is a distinctive form of muscular dystrophy which is often associated with cardiac abnormalities. Conduction disturbances are frequently observed, and may necessitate pacemaker implantation to prevent sudden death. In this case report, we present an autopsy of a 31-year-old man with X-linked EDMD who developed only minimal skeletal muscle symptoms, and who died from ventricular arrhythmia despite undergoing a previous pacemaker implantation. Ventricular arrhythmias in X-linked EDMD patients are also discussed.