Randomized trial of intravenous immunoglobulin maintenance treatment regimens in chronic inflammatory demyelinating polyradiculoneuropathy.

BACKGROUND AND PURPOSE: High peak serum immunoglobulin G (IgG) levels may not be needed for maintenance intravenous immunoglobulin (IVIg) treatment in chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) and such high levels may cause side effects. More frequent lower dosing may lead to more stable IgG levels and higher trough levels, which might improve efficacy. The aim of this trial is to investigate whether high frequent low dosage IVIg treatment is more effective than low frequent high dosage IVIg treatment. METHODS: In this randomized placebo-controlled crossover trial, we included patients with CIDP proven to be IVIg-dependent and receiving an individually established stable dose and interval of IVIg maintenance treatment. In the control arm, patients received their individual IVIg dose and interval followed by a placebo infusion at half the interval. In the intervention arm, patients received half their individual dose at half the interval. After a wash-out phase patients crossed over. The primary outcome measure was handgrip strength (assessed using a Martin Vigorimeter). Secondary outcome indicators were health-related quality of life (36-item Short-Form Health Survey), disability (Inflammatory Rasch-built Overall Disability Scale), fatigue (Rasch-built Fatigue Severity Scale) and side effects. RESULTS: Twenty-five patients were included and were treated at baseline with individually adjusted dosages of IVIg ranging from 20 to 80 g and intervals ranging from 14 to 35 days. Three participants did not complete the trial; the main analysis was therefore based on the 22 patients completing both treatment periods. There was no significant difference in handgrip strength change from baseline between the two treatment regimens (coefficient -2.71, 95% CI -5.4, 0.01). Furthermore, there were no significant differences in any of the secondary outcomes or side effects. CONCLUSIONS: More frequent lower dosing does not further improve the efficacy of IVIg in stable IVIg-dependent CIDP and does not result in fewer side effects.

New genotype-phenotype correlations in a large European cohort of patients with sarcoglycanopathy.

Sarcoglycanopathies comprise four subtypes of autosomal recessive limb-girdle muscular dystrophies (LGMDR3, LGMDR4, LGMDR5 and LGMDR6) that are caused, respectively, by mutations in the SGCA, SGCB, SGCG and SGCD genes. In 2016, several clinicians involved in the diagnosis, management and care of patients with LGMDR3-6 created a European Sarcoglycanopathy Consortium. The aim of the present study was to determine the clinical and genetic spectrum of a large cohort of patients with sarcoglycanopathy in Europe. This was an observational retrospective study. A total of 33 neuromuscular centres from 13 different European countries collected data of the genetically confirmed patients with sarcoglycanopathy followed-up at their centres. Demographic, genetic and clinical data were collected for this study. Data from 439 patients from 13 different countries were collected. Forty-three patients were not included in the analysis because of insufficient clinical information available. A total of 159 patients had a confirmed diagnosis of LGMDR3, 73 of LGMDR4, 157 of LGMDR5 and seven of LGMDR6. Patients with LGMDR3 had a later onset and slower progression of the disease. Cardiac involvement was most frequent in LGMDR4. Sixty per cent of LGMDR3 patients carried one of the following mutations, either in a homozygous or heterozygous state: c.229C>T, c.739G>A or c.850C>T. Similarly, the most common mutations in LMGDR5 patients were c.525delT or c.848G>A. In LGMDR4 patients the most frequent mutation was c.341C>T. We identified onset of symptoms before 10 years of age and residual protein expression lower than 30% as independent risk factors for losing ambulation before 18 years of age, in LGMDR3, LGMDR4 and LGMDR5 patients. This study reports clinical, genetic and protein data of a large European cohort of patients with sarcoglycanopathy. Improving our knowledge about these extremely rare autosomal recessive forms of LGMD was helped by a collaborative effort of neuromuscular centres across Europe. Our study provides important data on the genotype-phenotype correlation that is relevant for the design of natural history studies and upcoming interventional trials in sarcoglycanopathies.

Diagnostic value of additional histopathological fascia examination in idiopathic inflammatory myopathies.

BACKGROUND AND PURPOSE: Correct diagnosis of idiopathic inflammatory myopathies (IIM) may prevent harm from both lack of treatment in IIM patients and unnecessary treatment in non-IIM patients. However, it is unknown whether additional histopathological fascia examination may contribute to diagnosing IIM. METHODS: Thirty-two magnetic resonance imaging guided en bloc biopsies from patients diagnosed with IIM (except inclusion body myositis) from 2010 to 2017 were reviewed: dermatomyositis (DM) (n = 6), non-specific/overlap myositis (NM/OM) (n = 11), immune-mediated necrotizing myopathy (n = 12) and anti-synthetase syndrome (n = 3). Muscle biopsy specimens were examined according to the 2004 European Neuromuscular Centre (ENMC) criteria. Fascia was subsequently examined for the presence of lymphocytic infiltrates. Isolated fascia involvement was defined as the presence of lymphocytic infiltrates in the fascia/epimysium on histopathology in the absence of any ENMC muscle histopathology/immunohistochemistry criteria. RESULTS: One patient with DM (17%) and one patient with NM/OM (9%) had isolated fascia involvement. One patient with immune-mediated necrotizing myopathy (8%) and one patient with anti-synthetase syndrome (33%) had fascia involvement, albeit in combination with muscle involvement. CONCLUSION: Histopathological fascia examination may contribute to early diagnosis of DM and NM/OM in a small proportion of patients.

Muscle imaging in inherited and acquired muscle diseases.

In this review we discuss the use of conventional (computed tomography, magnetic resonance imaging, ultrasound) and advanced muscle imaging modalities (diffusion tensor imaging, magnetic resonance spectroscopy) in hereditary and acquired myopathies. We summarize the data on specific patterns of muscle involvement in the major categories of muscle disease and provide recommendations on how to use muscle imaging in this field of neuromuscular disorders.

Prose memory impairment in amyotrophic lateral sclerosis patients is related to hippocampus volume.

BACKGROUND AND PURPOSE: Thirty per cent of amyotrophic lateral sclerosis (ALS) patients have non-motor symptoms, including executive and memory deficits. The in vivo anatomical basis of memory deficits in ALS has not been elucidated. In this observational study, brain atrophy in relation to memory function was investigated in ALS patients and controls. METHODS: Twenty-six ALS patients without dementia and 21 healthy volunteers matched for gender, age and education level underwent comprehensive neuropsychological evaluation and T1- and T2-weighted 3 T magnetic resonance imaging scanning of the brain. Grey and white matter brain volumes were analysed using voxel-based morphometry and age related white matter changes were assessed. The most frequently abnormal memory test (<2 SD below normative data corrected for age, gender and education) was correlated with regional brain volume variations by multiple regression analyses with age, gender and total grey matter volumes as covariates. RESULTS: Immediate and delayed story recall scores were abnormal in 23% of ALS patients and correlated to bilateral hippocampus grey matter volume (r = 0.52 for both memory tests; P < 0.05; corrected for age, gender and total grey matter volume). This correlation was not found in healthy controls with similar age, education, anxiety and depression levels and white matter changes. CONCLUSIONS: Prose memory impairment is a frequent finding in this cohort and is associated with hippocampus volume in ALS patients without dementia. These findings complement previous hippocampus changes in imaging studies in ALS and suggest involvement of the hippocampus in cognitive dysfunction of ALS.

Clinical characterisation of Becker muscular dystrophy patients predicts favourable outcome in exon-skipping therapy.

OBJECTIVE: Duchenne and Becker muscular dystrophy (DMD/BMD) are both caused by mutations in the DMD gene. Out-of-frame mutations in DMD lead to absence of the dystrophin protein, while in-frame BMD mutations cause production of internally deleted dystrophin. Clinically, patients with DMD loose ambulance around the age of 12, need ventilatory support at their late teens and die in their third or fourth decade due to pulmonary or cardiac failure. BMD has a more variable disease course. The disease course of patients with BMD with specific mutations could be very informative to predict the outcome of the exon-skipping therapy, aiming to restore the reading-frame in patients with DMD. METHODS: Patients with BMD with a mutation equalling a DMD mutation after successful exon skipping were selected from the Dutch Dystrophinopathy Database. Information about disease course was gathered through a standardised questionnaire. Cardiac data were collected from medical correspondence and a previous study on cardiac function in BMD. RESULTS: Forty-eight patients were included, representing 11 different mutations. Median age of patients was 43 years (range 6-67). Nine patients were wheelchair users (26-56 years). Dilated cardiomyopathy was present in 7/36 patients. Only one patient used ventilatory support. Three patients had died at the age of 45, 50 and 76 years, respectively. CONCLUSIONS: This study provides mutation specific data on the course of disease in patients with BMD. It shows that the disease course of patients with BMD, with a mutation equalling a 'skipped' DMD mutation is relatively mild. This finding strongly supports the potential benefit of exon skipping in patients with DMD.

Oral ribose supplementation in dystroglycanopathy: A single case study.

Three forms of muscular dystrophy-dystroglycanopathies are linked to the ribitol pathway. These include mutations in the isoprenoid synthase domain-containing protein (ISPD), fukutin-related protein (FKRP), and fukutin (FKTN) genes. The aforementioned enzymes are required for generation of the ribitol phosphate linkage in the O-glycan of alpha-dystroglycan. Mild cases of dystroglycanopathy present with slowly progressive muscle weakness, while in severe cases the eyes and brain are also involved. Previous research showed that ribose increased the intracellular concentrations of cytidine diphosphate-ribitol (CDP-ribitol) and had a therapeutic effect. Here, we report the safety and effects of oral ribose supplementation during 6 months in a patient with limb girdle muscular dystrophy type 2I (LGMD2I) due to a homozygous FKRP mutation. Ribose was well tolerated in doses of 9 g or 18 g/day. Supplementation with 18 g of ribose resulted in a decrease of creatine kinase levels of 70%. Moreover, metabolomics showed a significant increase in CDP-ribitol levels with 18 g of ribose supplementation (p < 0.001). Although objective improvement in clinical and patient-reported outcome measures was not observed, the patient reported subjective improvement of muscle strength, fatigue, and pain. This case study indicates that ribose supplementation in patients with dystroglycanopathy is safe and highlights the importance for future studies regarding its potential effects.

Treatment of respiratory impairment in patients with motor neuron disease in the Netherlands: patient preference and timing of referral.

BACKGROUND AND PURPOSE: We assessed the first evaluation at a large ventilation clinic in the Netherlands to: (i) determine what proportion of patients with motor neuron disease would benefit from earlier referral; and (ii) examine the patient preferences regarding ventilatory support. METHODS: Observational study at a single centre with a catchment area of 7.6 million inhabitants. Data on disease status, the referral process and patients' preferences regarding ventilatory support were collected during the first home ventilation services (HVS) assessment and analysed for correlation with the presence of daytime hypercapnia and suspected nocturnal hypoventilation. The latter conditions require immediate (within 48 h) or subacute (within 3 weeks) initiation of ventilatory support. RESULTS: Vital capacity (in percentage of predicted value, VC%pred) was assessed by referring physicians in 84% of the 217 referred patients; the mean VC%pred was 69% (SD 16). One-hundred and ninety-one patients attended the first HVS assessment without ventilatory support, at a median of 21 days following referral: 18% had respiratory failure (daytime hypercapnia), 19% had normocapnia but were suspected of nocturnal hypoventilation, and 63% had normocapnia without symptoms. Following the HVS assessment, 25 patients (13%) declined home mechanical ventilation; this occurred more often in patients with (14/70) compared with patients without respiratory impairment (11/121; P < 0.05). CONCLUSION: A meaningful proportion of patients who desire ventilatory support are referred to a ventilation clinic after already developing respiratory failure. Future studies could examine means, including more sensitive respiratory measures, to detect those patients who could benefit from earlier referral.

Perioperative Care for Patients with Neuromuscular Disorders in the Netherlands - A Questionnaire Study Among Anaesthesiologists, Neurologists and Clinical Geneticists.

BACKGROUND: Patients with neuromuscular disorders are at increased risk of suffering perioperative complications. Current knowledge concerning this topic is based on small retrospective studies and expert opinion. Therefore, an individualized multidisciplinary approach to perioperative anaesthesia planning is invaluable to anticipate difficulties and to optimize outcomes. OBJECTIVE: To evaluate current practice regarding preoperative counselling and perioperative care of neuromuscular patients, with the aim to facilitate standardization and improvement of perioperative care for neuromuscular patients. METHODS: A questionnaire-based cross-sectional, observational study was conducted between July, 1st 2020 and December, 31st, 2020 in Dutch anaesthesia, neurology and clinical genetics departments. Main outcome measures were 1.) frequency of consultation requests for neuromuscular patients prior to surgery, 2.) current practice, educational activities and departmental approach to this topic and 3.) preoperative counselling of neuromuscular patients. RESULTS: A total of 83 departments participated. Consultations for a neuromuscular patient scheduled for anaesthesia were requested from anaesthesia and neurology department only infrequently. Local guidelines concerning perioperative care of neuromuscular patients were available in 36.4% of the participating departments. Quality of specific training for residents and staff anaesthetists/neurologists covering perioperative care of neuromuscular patients was rated as 'very good' or 'good' by 42.9%. Neuromuscular patients scheduled for surgery were 'always' or 'often' discussed in multidisciplinary meetings involving anaesthesiologists and neurologists in 20.8% of the participating departments. CONCLUSION: Perioperative care for neuromuscular patients in the Netherlands is highly variable and might benefit from guidelines, education of health care professionals and multidisciplinary meetings between anaesthesiologists and neurologists on a regular basis.

Desmin-related myopathy.

Desmin-related myopathy (DRM) is an autosomally inherited skeletal and cardiac myopathy, mainly caused by dominant mutations in the desmin gene (DES). We provide (i) a literature review on DRM, including clinical manifestations, inheritance, molecular genetics, myopathology and management and (ii) a meta-analysis of reported DES mutation carriers, focusing on their clinical characteristics and potential genotype-phenotype correlations. Meta-analysis: DES mutation carriers (n = 159) with 40 different mutations were included. Neurological signs were present in 74% and cardiological signs in 74% of carriers (both neurological and cardiological signs in 49%, isolated neurological signs in 22%, and isolated cardiological signs in 22%). More than 70% of carriers exhibited myopathy or muscular weakness, with normal creatine kinase levels present in one third of them. Up to 50% of carriers had cardiomyopathy and around 60% had cardiac conduction disease or arrhythmias, with atrioventricular block as an important hallmark. Symptoms generally started during the 30s; a quarter of carriers died at a mean age of 49 years. Sudden cardiac death occurred in two patients with a pacemaker, suggesting a ventricular tachyarrhythmia as cause of death. The majority of DES mutations were missense mutations, mostly located in the 2B domain. Mutations in the 2B domain were predominant in patients with an isolated neurological phenotype, whereas head and tail domain mutations were predominant in patients with an isolated cardiological phenotype.

Randomised controlled trial comparing two different intravenous immunoglobulins in chronic inflammatory demyelinating polyradiculoneuropathy.

BACKGROUND: Different preparations of intravenous immunoglobulin (IVIg) are considered to have comparable clinical efficacy but this has never been formally investigated. Some patients with chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) report that some IVIg brands are more effective than others. A liquid IVIg preparation is more user friendly and potentially can be infused at a faster rate. OBJECTIVES: The primary objective was to compare the efficacy of two different IVIg brands in CIDP. The secondary objective was to compare their safety. METHODS: This was an investigator-initiated multi-centre randomised controlled double-blind trial. Twenty-seven patients with active but stable CIDP treated with their individual stable IVIg (Gammagard S/D) maintenance dose and interval were randomised to receive four infusions of freeze-dried 5% IVIg (Gammagard S/D) or the new liquid 10% IVIg (Kiovig). The overall disability sum score (ODSS) was used as the primary outcome scale. The equivalence margin was defined as a difference of ≤1 point in mean ΔODSS between treatment groups. Main secondary outcome scales were the MRC sum score and the Vigorimeter. RESULTS: Repeated measurements analysis of variance, adjusted for baseline ODSS, showed a clinically insignificant treatment difference of 0.004 (95% CI -0.4 to 0.4). We also found no significant differences in any of the other outcome measures. Besides a lower occurrence of cold shivers in patients randomised to Kiovig (p=0.03), no significant differences were found in the occurrence of adverse events. CONCLUSIONS: This trial demonstrated equal clinical efficacy between a freeze-dried and a liquid IVIg preparation for maintenance treatment of CIDP.

Redefining the clinical phenotypes of non-dystrophic myotonic syndromes.

OBJECTIVE: To redefine phenotypical characteristics for both chloride (ClCh) and sodium channelopathies (NaCh) in non-dystrophic myotonic syndromes (NDM). METHODS: In a cross-sectional, nationwide study, standardised interviews and clinical bedside tests were performed in 62 genetically confirmed NDM patients, 32 ClCh and 30 NaCh. RESULTS: Standardised interviews revealed that ClCh reported a higher frequency of muscle weakness (75 vs 36.7%; p<0.01), the warm-up phenomenon (100 vs 46.7%; p<0.001), and difficulties in standing up quickly (90.6 vs 50.0%; p<0.001), running (90.6% vs 66.7; p<0.05) and climbing stairs (90.6 vs 63.3%; p = 0.01). Patients with NaCh reported an earlier onset (4.4 vs 9.6 years; p<0.001), and higher frequencies of paradoxical (50.0 vs 0%; p<0.001) and painful myotonia (56.7 vs 28.1%; p<0.05). Standardised clinical bedside tests showed a higher incidence and longer relaxation times of myotonia in the leg muscles for ClCh (100 vs 60%; mean duration of chair tests 12.5 vs 6.3 s; p<0.001), and in eyelid muscles for NaCh (96.7 vs 46.9%; mean relaxation time of 19.2 vs 4.3 s; p<0.001). Transient paresis was only observed in ClCh (62.5%) and paradoxical myotonia only in NaCh (30.0%). Multivariate logistic regression analyses allowed clinical guidelines to be proposed for genetic testing. CONCLUSION: This study redefined the phenotypical characteristics of NDM in both ClCh and NaCh. The clinical guidelines proposed may help clinicians working in outpatient clinics to perform a focused genetic analysis of either CLCN1 or SCN4A.

The Lambert-Eaton myasthenic syndrome 1988-2008: a clinical picture in 97 patients.

BACKGROUND: Neuromuscular symptoms in patients with Lambert-Eaton myasthenic syndrome (LEMS) and a small cell lung cancer (SCLC) develop more rapidly than in LEMS patients without a SCLC. We studied how this clinical information, which is readily available at the first consultation, can be used to predict the presence of SCLC. PATIENTS AND METHODS: In our study we included 52 LEMS patients with SCLC and 45 non-tumor patients (NT-LEMS). We interviewed patients using a structured checklist and reviewed their clinical records. We compared frequency and onset of symptoms during the course of LEMS. RESULTS: In the first six months, over half the SCLC-LEMS patients had developed seven separate symptoms, while NT-LEMS patients developed only two symptoms. Proximal leg weakness and dry mouth were early symptoms in both groups. Rapid involvement of proximal arm muscles (p=0.0001), distal arm muscles (p=0.0037), distal leg muscles (p=0.0002), dysartria (p=0.0091) and the presence of erectile dysfunction (p=0.007) were found significantly more often in SCLC-LEMS patients in both cohorts. Cerebellar symptoms, although present in 9% of LEMS patients, were almost exclusively related to SCLC-LEMS. CONCLUSION: A rapidly progressive course of disease from onset in LEMS patients should raise a high suspicion of SCLC. Special attention should be paid to involvement of upper extremities, involvement of distal arm and distal leg muscles, to erectile dysfunction and probably ataxia in order to discriminate between SCLC-LEMS and NT-LEMS.

[Myositis: more than a muscle disease]. / Myositis is meer dan een spierziekte.

Idiopathic inflammatory myopathy (IIM), commonly referred to as "myositis", is a rare but treatable auto-immune disease that is often misdiagnosed or diagnosed after significant delay. Using three clinical case reports as introductory examples, an overview is given - and pitfalls are discussed - of the diagnosis and treatment of myositis. Disease features are often extra-muscular in nature, may vary considerably between patients, and are frequently non-specific. Myositis-related morbidity is high and myositis can be fatal, mainly due to cancer and interstitial lung disease. As such, we stress the importance of early recognition of this severe disease and timely referral of a patient with a (suspected) IIM to a multidisciplinary team for optimal diagnosis and disease management.

Lamin A/C mutations with lipodystrophy, cardiac abnormalities, and muscular dystrophy.

Mutations in the lamin A/C gene are found in Emery-Dreifuss muscular dystrophy, limb girdle muscular dystrophy with cardiac conduction disturbances, dilated cardiomyopathy with conduction system disease, and familial partial lipodystrophy. Cases with lamin A/C mutations presenting with lipodystrophy in combination with cardiac and/or skeletal muscle abnormalities are described.

A novel gamma-sarcoglycan mutation causing childhood onset, slowly progressive limb girdle muscular dystrophy.

Limb girdle muscular dystrophy is a heterogeneous group of disorders. One autosomal recessive subtype, LGMD2C, has been linked to chromosome 13, and is caused by gamma-sarcoglycan deficiency in muscle. This report describes a novel missense mutation identified in a large consanguineous Dutch family with LGMD. This mutation leads to reduction of gamma-sarcoglycan, and gives rise to a childhood-onset, slowly-progressive dystrophy.

A diagnostic fluorescent marker kit for six limb girdle muscular dystrophies.

The autosomal progressive muscular dystrophies which are grouped together under the term limb girdle muscular dystrophies (LGMD) are diseases characterized by a progressive impairment of the proximal limb muscles and myopathic changes on electromyogram and muscle biopsy. Eight independent purely recessive genetic entities have been recognized in this group of diseases by genetic localization or causative gene identification. We have developed fluorescent genetic markers bracketing six of these loci (LGMD2A-LGMD2F). The marker loci were genotyped in 96 LGMD2 families leading to genetic definition of 25 of them either with a high likelihood or with a suggested localization (7 LGMD2A, 5 LGMD2B, 4 LGMD2C, 4 LGMD2D, 2 LGMD2E and 3 LGMD2F). In addition, 18 families were excluded for all six tested loci; for 45 of the 53 remaining families at least one exclusion could be demonstrated. This kit, which makes the rapid genetic testing of LGMD2 families possible, may be useful in a diagnostic process.

Sarcoglycanopathies in Dutch patients with autosomal recessive limb girdle muscular dystrophy.

Within a group of 76 sporadic/autosomal recessive limb girdle muscular dystrophy (LGMD) patients we tried to identify those with LGMD type 2C-E. Muscle biopsy specimens of 40 index patients, who had 22 affected sibs, were analyzed immuno-histochemically for the presence of three subunits: alpha-, beta-, and gamma-sarcoglycans. Abnormal sarcoglycan expression was established in eight patients, with six affected sibs. In one patient gamma-sarcoglycan was absent, and both alpha- and beta-sarcoglycans were reduced. In the remaining seven patients gamma-sarcoglycan was (slightly) reduced, and alpha- and beta-sarcoglycans were absent or reduced. By DNA sequencing mutations were detected in one of the three sarcoglycan genes in all eight cases. Three patients had mutations in the alpha-, three in the beta-, and two in the gamma-sarcoglycan gene. The patients with sarcoglycanopathy comprised the more severely affected cases (P=0.04). In conclusion, sarcoglycanopathy was identified in 23 % (14/62) of the autosomal recessive LGMD patients.

The heart in limb girdle muscular dystrophy.

OBJECTIVE: To assess the frequency, nature, and severity of cardiac abnormalities in limb girdle muscular dystrophy, and its relation to age and weakness in various genotypes. DESIGN: In 26 autosomal dominant, 38 autosomal recessive, and 33 sporadic strictly defined patients with limb girdle muscular dystrophy, cardiac evaluation included history, physical examination, chest x ray, electrocardiography, 24 hour ECG Holter monitoring, and echocardiography. In 35 of the 71 autosomal recessive and sporadic cases muscle biopsies were available for sarcoglycan analysis. MAIN RESULTS: Dilated cardiomyopathy was present in one autosomal dominant case and in three advanced autosomal recessive or sporadic patients, of whom two were found to have alpha sarcoglycan deficiency. Two of these three patients and three other cases showed ECG abnormalities known to be characteristic of the dystrophinopathies. A strong association between the absence of alpha sarcoglycan and the presence of dilated cardiomyopathy was found (p = 0.04). In six autosomal dominant cases there were atrioventricular (AV) conduction disturbances, increasing in severity with age and in concomitant presence of muscle weakness. Pacemaker implantation was necessary in four. CONCLUSIONS: 10% of these patients had clinically relevant cardiac abnormalities. In autosomal dominant limb girdle muscular dystrophy one subtype characterised by muscle weakness and AV conduction disturbances is recognised. In the course of autosomal recessive/sporadic limb girdle muscular dystrophy, dilated cardiomyopathy may develop, probably related to deficiency of dystrophin associated proteins.