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1.  Right atrial preference pacing algorithm in the prevention of paroxysmal atrial fibrillation in myotonic dystrophy type 1 patients: a long term follow-up study 
Acta Myologica  2012;31(2):139-143.
Atrial Preference Pacing (APP) is a pacemaker (PM) algorithm that works by increasing the atrial pacing rate to achieve continuous suppression of a spontaneous atrial rhythm and prevent supraventricular tachyarrhythmias. We have previously shown that atrial preference pacing may significantly reduce the number and the duration of AF episodes in myotonic dystrophy type 1 (DM1) patients who are paced for standard indications.
However, the role that APP therapies play in the prevention of AF in a long-term period remains still unclear. Aim of the present prospective study was to evaluate whether this beneficial effect is maintained for 24-months follow-up period.
To this aim, 50 patients with Myotonic Dystrophy type 1 who underwent dual-chamber PM implantation for first- and second- degree atrioventricular block, were consecutively enrolled and followed for 2 years. One month later the stabilization period, after the implantation, they were randomized to APP algorithm programmed OFF or ON for 6 months each, using a cross-over design, and remained in the same program for the second year. The results showed that while the number of AF episodes during active treatment (APP ON phases) was lower than that registered during no treatment (APP OFF phases), no statistically significant difference was found in AF episodes duration between the two phases. Furthermore, during the APP OFF and APP ON phases, the percentage of atrial pacing was 0 and 99%, respectively, while the percentage of ventricular pacing did not show differences statistically significant (11 vs. 9%, P = 0.2). Atrial premature beats were significantly higher during APP OFF phases than during APP ON phases. Lead parameters remained stable over time and there were no lead-related complications. Based on these 24-months follow-up data, we can conclude that, in DM1 patients who underwent dual-chamber PM implantation, APP is an efficacy algorithm for preventing paroxysmal AF even in long term periods.
PMCID: PMC3476853  PMID: 23097606
myotonic dystrophy; atrial preference pacing; atrial fibrillation
2.  Improvement of survival in Duchenne Muscular Dystrophy: retrospective analysis of 835 patients 
Acta Myologica  2012;31(2):121-125.
Duchenne Muscular Dystrophy (DMD) is the most common muscle disease in children. Historically, DMD results in loss of ambulation between ages 7 and 13 years and death in the teens or 20s. In order to determine whether survival has improved over the decades and whether the impact of nocturnal ventilation combined with a better management of cardiac involvement has been able to modify the pattern of survival, we reviewed the notes of 835 DMD patients followed at the Naples Centre of Cardiomyology and Medical Genetics from 1961 to 2006. Patients were divided, by decade of birth, into 3 groups: 1) DMD born between 1961 and 1970; 2) DMD born between 1971 and 1980; 3) DMD born between 1981 and 1990; each group was in turn subdivided into 15 two-year classes, from 14 to 40 years of age. Age and causes of death, type of cardiac treatment and use of a mechanical ventilator were carefully analyzed.
The percentage of survivors in the different decades was statistically compared by chi-square test and Kaplan-Meier survival curves analyses. A significant decade on decade improvement in survival rate was observed at both the age of 20, where it passed from 23.3% of patients in group 1 to 54% of patients in group 2 and to 59,8% in patients in group 3 (p < 0.001) and at the age of 25 where the survival rate passed from 13.5% of patients in group 1 to 31.6% of patients in group 2 and to 49.2% in patients in group 3 (p < 0.001).
The causes of death were both cardiac and respiratory, with a prevalence of the respiratory ones till 1980s. The overall mean age for cardiac deaths was 19.6 years (range 13.4-27.5), with an increasing age in the last 15 years. The overall mean age for respiratory deaths was 17.7 years (range 11.6-27.5) in patients without a ventilator support while increased to 27.9 years (range 23-38.6) in patients who could benefit of mechanical ventilation.
This report documents that DMD should be now considered an adulthood disease as well, and as a consequence more public health interventions are needed to support these patients and their families as they pass from childhood into adult age.
PMCID: PMC3476854  PMID: 23097603
Duchenne; survival; cardiomyopathy
3.  Survival in Duchenne muscular dystrophy 
Acta Myologica  2012;31(2):117-120.
Objective:
To determine the survival in a population of German patients with Duchenne muscular dystrophy.
Patients and methods:
Information about 94 patients born between 1970 and 1980 was obtained by telephone interviews and questionnaires. In addition to age of death or actual age during the investigation, data concerning clinical course and medical interventions were collected.
Results:
67 patients with molecularly confirmed diagnoses had a median survival of 24.0 years. Patients without molecular confirmation (clinical diagnosis only) had a chance of 67 % to reach that age. Grouping of our patient cohort according to the year of death (before and after 2000), ventilation was recognized as main intervention affecting survival with ventilated reaching a median survival of 27.0 years. For those without ventilation it was 19.0 years.
Conclusion and clinical relevance:
our study provides survival data for a cohort of DMD patients in Germany stratified by year of death. Median survival was 24.0 years in patients confirmed by molecular testing. Ventilated patients had a median survival of 27 years. We consider this piece of information helpful in the medical care of DMD patients.
PMCID: PMC3476855  PMID: 23097602
duchenne muscular dystrophy; survival; ventilation
4.  TARDBP mutations are not a frequent cause of ALS in Finnish patients 
Acta Myologica  2012;31(2):134-138.
In previous studies 1-3 % of ALS patients have TARDBP mutations as the cause of the disease. TARDBP mutations have been reported in ALS patients in different populations but so far there are no studies on the frequency of TARDBP mutations in Finnish ALS patients. A cohort of 50 Finnish patients, 44 SALS and 6 FALS patients, were included in the study. Genomic DNA was extracted from venous blood or muscle tissue and a mutation analysis of TARDBP was performed. No definitely pathogenic mutations could be identified in TARDBP in our patient cohort. However, two previously unknown variations were found: one silent mutation in exon 2 and one relatively deep intronic single nucleotide insertion in intron 5. In addition, two previously known non-pathogenic polymorphisms in intron 5 were detected. The size of our cohort is obviously not large enough to conclusively exclude TARDBP mutations as a very rare cause of ALS in Finland. However, based on our results TARDBP mutations do not appear to be a frequent cause of familial or sporadic ALS in Finland.
PMCID: PMC3476858  PMID: 23097605
Amyotrophic lateral sclerosis; mutation screening; TARDBP
5.  ClC1 chloride channel in myotonic dystrophy type 2 and ClC1 splicing in vitro 
Acta Myologica  2012;31(2):144-153.
Myotonic dystrophy type 2 (DM2) is caused by CCTG-repeat expansions. Occurrence of splicing and mutations in the muscle chloride channel gene CLCN1 have been reported to contribute to the phenotype. To examine the effect of CLCN1 in DM2 in Germany, we determined the frequency of a representative ClC1 mutation, R894X, and its effect on DM2 clinical features. Then, we examined CLCN1 mRNA splice variants in patient muscle functionally expressed the most abundant variant, and determined its subcellular localization. Finally, we established a cellular system for studying mouse clcn1 pre-mRNA splicing and tested effects of expression of (CCUG)18, (CUG)24 and (AAG)24 RNAs. The R894X mutation was present in 7.7% of DM2 families. DM2 R894X-carriers had more myotonia and myalgia than non-carriers. The most abundant CLCN1 splice variant in DM2 (80% of all transcripts) excluded exons 6-7 and lead to a truncated ClC1236X protein. Heterologous ClC1236X expression did not yield functional channels. Co-expression with ClC1 did not show a dominant negative effect, but a slightly suppressive effect. In C2C12 cells, the clc1 splice variants generated by (CCUG)18-RNA resembled those in DM2 muscle and differed from those generated by (CUG)24 and (AAG)24. We conclude that ClC1 mutations exert gene dose effects and enhance myotonia and pain in DM2 in Germany. Additionally, the ClC1236X splice variant may contribute to myotonia in DM2. Since splice variants depend on the types of repeats expressed in the cellular C2C12 model, similar cell models of other tissues may be useful for studying repeatdependent pathogenetic mechanisms more easily than in transgenic animals.
PMCID: PMC3476861  PMID: 23097607
PROMM; myotonic dystrophy; chloride channel
6.  The impact of permanent muscle weakness on quality of life in periodic paralysis: a survey of 66 patients 
Acta Myologica  2012;31(2):126-133.
The periodic paralyses are hereditary muscle diseases which cause both episodic and permanent weakness. Permanent weakness may include both reversible and fixed components, the latter caused by fibrosis and fatty replacement. To determine the degree of handicap and impact of permanent weakness on daily life, we conducted a 68-question online survey of 66 patients over 41 years (mean age, 60 ± 14 years). Permanent weakness occurred in 68%, muscle pain in 82% and muscle fatigue in 89%. Eighty-three percent of patients reported themselves as moderately to very active between ages 18-35. At the time of the survey only 14% reported themselves as moderately to very active. Contrary to the literature, only 21% of patients reported decreased frequency of episodic weakness with increased age. Sixty-seven percent had incurred injuries due to falls. Mobility aids were required by 49%. Strength increased in 49% of patients receiving professional physiotherapy and in 62% performing self-managed exercise routines. A decline of strength was observed by 40% with professional and by 16% with self-managed exercise routine, suggesting that overworking muscles may not be beneficial. There is an average of 26 years between age at onset and age at diagnosis indicating that diagnostic schemes can be improved. In summary our data suggests that permanent muscle weakness has a greater impact on the quality of life of patients than previously anticipated.
PMCID: PMC3476862  PMID: 23097604
periodic paralysis; myopathy; paramyotonia congenita
7.  A novel N440K sodium channel mutation causes myotonia with exercise-induced weakness - exclusion of CLCN1 exon deletion/duplication by MLPA 
Acta Myologica  2011;30(2):133-137.
We report a 4-generation Turkish family with 10 affected members presenting with myotonia and potassium- and exerciseinduced paralytic attacks. The clinical presentation was neither typical for the chloride channel myotonias Thomsen and Becker nor for the separate sodium channel myotonia entities potassiumaggravated myotonia, paramyotonia congenita, and hyperkalemic periodic paralysis. It is best described by a combination of potassium-aggravated myotonia and hyperkalemic periodic paralysis. We excluded exonic chloride channel mutations including CLCN1 exon deletion/duplication by MLPA. Instead we identified a novel p.N440K sodium channel mutation that is located at the inner end of segment S6 of repeat I. We discuss the genotype phenotype relation.
PMCID: PMC3235863  PMID: 22106717
chloride channel myotonia Thomsen and Becker; sodium channel myotonia; hyperkalemic periodic paralysis; potassiumaggravated myotonia; paramyotonia congenita; CLCN1; MLPA
8.  Dysferlinopathy course and sportive activity: clues for possible treatment 
Acta Myologica  2011;30(2):127-132.
LGMD2B is a frequent proximo-distal myopathy with rapid evolution after age 20. Exacerbating factors may be physical exercise and inflammation. There is very little information about the effect of sportive activity in LGMD2B, since eccentric exercise frequently results in muscle damage. LGMD2B has often an onset with myalgia and MRI imaging (STIR-sequences) shows myoedema. In a prolonged observational study of a series of 18 MM/LGMD2B patients we have studied the pattern of clinical and radiological evolution. The disease has an abrupt onset in the second decade and most patients perform sports before definite disease onset. On the basis of Gardner-Medwin and Walton scale, grade 4 is reached two years faster in patients who performed sports (over 1000 hours). Other considerations regarding pathogenetic mechanism and response to treatment show a poor response to immunosuppressive treatment of muscle inflammation. Preventing a strenuous physical activity should be recommended in patients with high CK and diagnosed or suspected to have dysferlin deficiency.
PMCID: PMC3235880  PMID: 22106716
dysferlin; pathogenesis; physical exercise; sport activity
9.  The Microglial-Motoneuron dialogue in ALS 
Acta Myologica  2011;30(1):4-8.
SUMMARY
Neuroinflammation is a pathological hallmark of neurodegenerative diseases including amyotrophic lateral sclerosis (ALS), and is characterized by activated microglia at sites of neuronal injury. In ALS. neurons do not die alone; neuronal injury is noncell- autonomous and depends upon a well-orchestrated dialogue between motor neurons and microglia. Evidence from transgenic models expressing mutant superoxide dismutase 1 (SOD) suggests that the dialogue between motor neurons and microglia initially protects motor neurons. However, with increasing stress and injury within motor neurons, induced by the presence of misfolded proteins such as mSOD1, mitochondrial function and axoplasmic flow are impaired and endoplasmic reticulum stress is induced; misfolded proteins themselves or alternate signals are released from motor neurons and activate microglia. Activated microglia, in turn, switch from anti-inflammatory and neuroprotective to proinflammatory and neurotoxic. Neurotoxic signaling from motor neurons promotes microglial release of reactive oxygen species and pro-inflammatory cytokines further enhancing motor neuron stress and cell injury and initiating a self-propagating cycle of motor neuron injury and cell death. A greater understanding of how to restore the imbalance between neuroprotection and cytotoxicity will depend upon a greater understanding of the motor neuron-microglial dialogue.
PMCID: PMC3185827  PMID: 21842586
Microglia; Motoneurons; ALS
10.  Sporadic-inclusion body myositis (s-IBM) is not so prevalent in Istanbul/Turkey: a muscle biopsy based survey 
Acta Myologica  2011;30(1):34-36.
SUMMARY
In a muscle biopsy based study, only 9 out of 5450 biopsy samples, received from all parts of greater Istanbul area, had typical clinical and most suggestive light microscopic sporadic-inclusion body myositis (s-IBM) findings. Two other patients with and ten further patients without characteristic light microscopic findings had referring diagnosis of s-IBM. As the general and the ageadjusted populations of Istanbul in 2010 were 13.255.685 and 2.347.300 respectively, the calculated corresponding ‘estimated prevalences' of most suggestive s-IBM in the Istanbul area were 0.679 X 10-6 and 3.834 X 10-6. Since Istanbul receives heavy migration from all regions of Turkey and ours is the only muscle pathology laboratory in Istanbul, projection of these figures to the Turkish population was considered to be reasonable and an estimate of the prevalence of s-IBM in Turkey was obtained.
The calculated ‘estimated prevalence' of s-IBM in Turkey is lower than the previously reported rates from other countries. The wide variation in the prevalence rates of s-IBM may reflect different genetic, immunogenetic or environmental factors in different populations.
PMCID: PMC3185828  PMID: 21842592
Sporadic inclusion body myositis; s-IBM; prevalence; myopathy
11.  HIV-related neuromuscular diseases: nemaline myopathy, amyotrophic lateral sclerosis and bibrachial amyotrophic diplegia 
Acta Myologica  2011;30(1):29-31.
SUMMARY
The human immunodeficiency virus (HIV) causes diverse disorders of the brain, spinal cord and peripheral nerves. Rarely, polymyositis and myoglobinuria are seen. Two other neuromuscular syndromes in people with HIV antibodies are nemaline myopathy and bibrachial amyotrophic diplegia, a form of motor neuron disease. The associations between these diseases and the possibility that HIV infection could be a risk factor for either amyotrophic lateral sclerosis (ALS) itself or other motor neuron diseases are investigated.
PMCID: PMC3185829  PMID: 21842590
HIV-Related Neuromuscular Diseases; nemaline myopathy; amyotrophic lateral sclerosis; bibrachial amyotrophic diplegia
12.  Continuous muscle activity, Morvan's syndrome and limbic encephalitis: ionic or non ionic disorders? 
Acta Myologica  2011;30(1):32-33.
SUMMARY
The early pathophysiologic study showed increasing evidence that autoimmunity is implicated in the pathogenesis of neuromyotonia. Antibodies to voltage gated potassium channel were detected in the serum of patients who had peripheral nerves hyperexcitability and also Morvan's disease or limbic encephalitis. These discoveries offered new approaches to treatments.
Recently, antibodies previously attributed to VGKC recognise 2 surface antigens LGI1 and CASPR2 into the VGKC complex. Finally, VGKC antibodies are directed to 2 proteins the first one is a key hippocampic protein containing pre and post synaptic proteins. The second one CASPR2 is an hippocampic and paranodal protein.
There clinical significance is different: hyperexcitability, limbic encephalitis without thymoma for LGI1, hyperexcitability, Morvan limbic encephalitis and frequent thymoma for CASPR2.
In conclusion, the term NMT - LE - VGKC should be changed to NMT- LE with LGI1 and CASPR2 antibodies and classified as auto immune synaptic disorders. Mutations in genes encoding both these proteins are found in hereditary epilepsy and other syndromes. Various potassium channelopathies are closely linked to Morvan's syndromes. A new classification of antibodies will be necessary.
PMCID: PMC3185830  PMID: 21842591
Neuromyotonia; autoimmunity; Isaac's Syndrome
13.  Desmin A213V substitution represents a rare polymorphism but not a mutation and is more prevalent in patients with heart dilation of various origins 
Acta Myologica  2011;30(1):42-45.
Several desmin mutations have been described in patients with cardiomyopathies and distal myopathies. Among them, A213V substitution has been associated with three completely different clinical phenotypes: restrictive cardiomyopathy, dilated cardiomyopathy and isolated distal myopathy. However, the identification of this substitution also in control subjects has highlighted the question if the A213V shift represents a conditional mutation, giving rise to cardiomyopathy only in the presence of other predisposing factors. The aim of the present work was to study the potential role of this substitution in predisposing to heart dilation.
Methods and results. We screened 108 patients with heart dilation due to ischemic heart disease, alcoholic cardiomyopathy or viral myocarditis, and 300 healthy controls for the presence of A213V substitution by direct sequencing and confirmed the results by site-specific restriction. In the control group A213V substitution was identified in 3 out of 300 patients, representing a rare polymorphism with a frequency of approximately 1%, which corresponds to the earlier reported frequency. In the study group A213V substitution was found in 5 out of 108 cases, corresponding to approximately 4.6% (p < 0.035). Therefore we conclude that A213V desmin substitution represents a conditional mutation, i.e. a rare polymorphism that plays a role as a predisposing factor resulting in maladaptive heart remodelling in the presence of other pathological factors.
PMCID: PMC3185831  PMID: 21842594
Desmin; polymorphisms; heart dilation
14.  Activation of NF-kB pathway in Duchenne muscular dystrophy: relation to age 
Acta Myologica  2011;30(1):16-23.
SUMMARY
Muscle degeneration in Duchenne muscular dystrophy (DMD) is exacerbated by increased oxidative stress and the endogenous inflammatory response, with a key role played by nuclear factor kappa-B (NF-κB) and other related factors such as tumor necrosis factor (TNF)-α and interleukin (IL)-6. However the time course of expression of these molecules and the relation with the amount of necrosis and regeneration have never been investigated.
The expression of NF-κB, the cytokines TNF-α and IL-6 and the antioxidant enzyme glutathione peroxidase (GPx) was studied in muscle samples from 14 patients with DMD aged between 2 and 9 years. Moreover a quantitative morphological evaluation was performed to evaluate necrotic and regenerative areas.
The highest percentage of necrosis was revealed within 4 years of age, with a significant negative correlation with age (p < 0.003), which paralleled to a significant decrement of regenerating area (p < 0.0004). We reported the novel observation that the number of NF-κB positive fibers and the NF-κB DNA-binding activity, revealed by EMSA, are high at two years of life and significantly decline with age (p < 0.0005 and p < 0.0001). The expression of TNF-α, IL-6 and GPx was upregulated in DMD muscles compared to controls and significantly increased with age on realtime PCR analysis (p < 0.0002; p < 0.0005; p < 0.03 respectively) and ELISA (p < 0.002; p < 0.02; p < 0.0001 respectively).
Since anti-inflammatory and anti-oxidant drugs are nowadays being translated to clinical studies in DMD, the reported insights on these therapeutic targets appear relevant. Further studies on the interactions among these pathways in different DMD phases and on the response of these cascades to treatments currently under investigation are needed to better elucidate their relevance as therapeutic targets.
PMCID: PMC3185832  PMID: 21842588
DMD; NF-κB; TNF-α
15.  Cardiological manifestations of mitochondrial respiratory chain disorders 
Acta Myologica  2011;30(1):9-15.
Mitochondrial Respiratory Chain Disorders (MRCD) are a heterogeneous group of disorders that share the involvement of the cellular bioenergetic machinery due to molecular defects affecting the mitochondrial oxidative phosphorylation system (OXPHOS).
Clinically, they usually involve multiple tissues although they tend to mainly affect nervous system and skeletal muscle. Cardiological manifestations are frequent and include hypertrophic or dilated cardiomyopathies and heart conduction defects, being part of adult or infantile multisystemic mitochondrial disorders or, less frequently, presenting as isolated clinical condition.
The aim of this review is to update the cardiological manifestations in both adult and infantile mitochondrial disorders going briefly over mitochondrial genetics.
Cardiac involvement is a common feature associated with early and late onset forms of MRCD. In particular cases, these conditions should be considered into the diagnostic algorithm of idiopathic cardiomyopathies. Physicians strictly related with this disorders need to be aware of heart complications and therefore periodical cardiological examinations should be performed in such patients. Finally, therapeutic strategies are suggested to treat cardiac disorders in MRCD
PMCID: PMC3185833  PMID: 21842587
Mitochondrial cardiomyopathies; molecular diagnosis; therapy
16.  Mesoangioblasts of inclusion-body myositis: a twofold tool to study pathogenic mechanisms and enhance defective muscle regeneration 
Acta Myologica  2011;30(1):24-28.
SUMMARY
Mesoangioblasts are a class of adult stem cells of mesoderm origin, potentially useful for the treatment of primitive myopathies of different etiology. Extensive in vitro and in vivo studies in animal models of muscular dystrophy have demonstrated the ability of mesoangioblast to repair skeletal muscle when injected intra-arterially. In a previous work we demonstrated that mesoangioblasts obtained from diagnostic muscle biopsies of IBM patients display a defective differentiation down skeletal muscle and this block can be corrected in vitro by transient MyoD transfection. We are currently investigating different pathways involved in mesoangioblasts skeletal muscle differentiation and exploring alternative stimulatory approaches not requiring extensive cell manipulation. This will allow to obtain safe, easy and efficient molecular or pharmacological modulation of pro-myogenic pathways in IBM mesoangioblasts. It is of crucial importance to identify factors (ie. cytokines, growth factors) produced by muscle or inflammatory cells and released in the surrounding milieu that are able to regulate the differentiation ability of IBM mesoangioblasts. To promote myogenic differentiation of endogenous mesoangioblasts in IBM muscle, the modulation of such target molecules selectively dysregulated would be a more handy approach to enhance muscle regeneration compared to transplantation techniques.
Studies on the biological characteristics of IBM mesoangioblasts with their aberrant differentiation behavior, the signaling pathways possibly involved in their differentiation block and the possible strategies to overcome it in vivo, might provide new insights to better understand the etiopathogenesis of this crippling disorder and to identify molecular targets susceptible of therapeutic modulation.
PMCID: PMC3185835  PMID: 21842589
mesoangioblasts; myogenic stem cells; inclusion-body myositis; muscle regeneration
17.  A correlative study of Quantitative EMG and biopsy findings in 31 patients with myopathies 
Acta Myologica  2011;30(1):37-41.
A direct correlation of QEMG with muscle biopsy findings might help delineate the sensitivity of QEMG in identifying muscle pathology as well as provide information on electrophysiological- histological correlations. In a study of 31 patients with a variety of myopathies we found that the sensitivity of QEMG was between 24 to 69% depending of the specific method of signal analysis. The positive predictive value of abnormal QEMG was more than 90% while its negative predictive value was only about 20%. Amplitude outlier analysis was superior especially in minimally weak muscles (MRC > 4) and was particularly sensitive at detecting increased variability in fiber size and more subtle myopathic changes.
PMCID: PMC3185837  PMID: 21842593
Quantitative electromyography; muscle biopsy; sensitivity
18.  State of the art in muscle glycogenoses  
Acta Myologica  2010;29(2):339-342.
The recognition of a series of metabolic/enzymatic dysfunctions in glycogenoses has allowed new therapeutic advances for their treatment due to the development of recombinant enzyme. A recent advance appears enzymatic replacement therapy (ERT) in glycogenosis type II in both infantile, juvenile and adult form. Targeted manipulation of diet has been tried both in glycogenosis type II (Pompe disease) and type V (Mc Ardle disease).
PMCID: PMC3040590  PMID: 21314016
Glycogenosis; Pompe disease; McArdle disease; enzyme replacement therapy
19.  State of the art in muscle lipid diseases 
Acta Myologica  2010;29(2):351-356.
Fatty acid oxidation in mitochondrial matrix is a major source of energy in muscle, especially when physiological energy demand is increased and exceeds what can be provided through glycolysis. Not surprisingly, a group of muscle disorders due to defects in this system usually leads to the development of acute rhabdomyolysis in conditions such as infection, fasting and prolonged exercise. This group includes β-oxidation cycle defects and deficiencies of carnitine palmitoyltransferase II (CPTII) and very-long-chain acyl-CoA dehydrogenase (VLCAD). Muscle pathology is usually not very helpful for the diagnosis but immunohistochemistry may be useful for screening VLCAD deficiency. Another group of lipid dysmetablolism is lipid storage myopathy (LSM) that is pathologically characterized by increased lipid droplets both in number and size in muscle fibers. So far, causative genes have been identified in four different LSMs, comprising primary carnitine deficiency, multiple acyl-CoA dehydrogenase deficiency or glutaric aciduria type II, neutral lipid storage disease with ichthyosis, and neutral lipid storage disease with myopathy. Clinically, the LSM patients show slowly progressive muscle weakness unlike the former group. Final diagnosis is usually made by specific biochemical assays with mutation analyses. As some effective drugs have been widely used and some promising therapies are under certified, comprehensive understanding of these diseases from clinical, pathological and molecular aspects would be of much help for the patients.
PMCID: PMC3040591  PMID: 21314018
Lipid storage myopathy; primary carnitine deficiency; multiple acyl-coenzyme A dehydrogenase deficiency; neutrolipid storage disease; carnitine palmitoyltransferase II; very long-chain acyl-CoA dehydrogenase
20.  State of the art in hereditary muscle channelopathies  
Acta Myologica  2010;29(2):343-350.
A combination of electrophysiological and genetic studies has resulted in the identification of several skeletal muscle disorders to be caused by pathologically functioning ion channels and has led to the term channelopathies. Typical hereditary muscle channelopa thies are congenital myasthenic syndromes, non-dystrophic myotonias, periodic paralyses, malignant hyperthermia, and central core disease. Most muscle channelopathies are commonly considered to be benign diseases. However, lifethreatening weakness episodes or progressive permanent weakness may make these diseases severe, particularly the periodic paralyses (PP). Even in the typical PP forms characterized by episodic occurrence of weakness, up to 60% of the patients suffer from permanent weakness and myopathy with age. In addition, some PP patients present with a predominant progressive muscle weakness phenotype. The weakness can be explained by strongly depolarized fibers that take up sodium and water and that are electrically inexcitable. Drugs that repolarize the fiber membrane can restore muscle strength and may prevent progression.
PMCID: PMC3040592  PMID: 21314017
Congenital myasthenic syndromes; non-dystrophic myotonias; periodic paralyses; susceptibility to malignant hyperthermia; central core disease
21.  Mendelian bases of myopathies, cardiomyopathies, and neuromyopathies 
Acta Myologica  2010;29(1):1-20.
Summary
A second genetic revolution is approaching thanks to next-generation DNA sequencing technologies. In the next few years, the 1,000$-genome sequencing promises to reveal every individual variation of DNA. There is, however, a major problem: the identification of thousands of nucleotide changes per individual with uncertain pathological meaning. This is also an ethical issue. In the middle, there is today the possibility to address the sequencing analysis of genetically heterogeneous disorders to selected groups of genes with defined mutation types. This will be cost-effective and safer.
We assembled an easy-to manage overview of most Mendelian genes involved in myopathies, cardiomyopathies, and neuromyopathies. This was entirely put together using a number of open access web resources that are listed below. During this effort we realized that there are unexpected countless sources of data, but the confusion is huge. In some cases, we got lost in the validation of disease genes and in the difficulty to discriminate between polymorphisms and disease-causing alleles. In the table are the annotated genes, their associated disorders, genomic, mRNA and coding sizes. We also counted the number of pathological alleles so far reported and the percentage of single nucleotide mutations.
PMCID: PMC2954584  PMID: 22029103
22.  Severe phenotype of a patient with autosomal recessive centronuclear myopathy due to a BIN1 mutation 
Acta Myologica  2009;28(3):91-93.
Summary
Centronuclear myopathy (CNM) is a rare hereditary congenital myopathy characterized by muscular hypotonia and abnormal centralization of nuclei in muscle fibers. The autosomal recessive (AR) form presents from birth to childhood, followed by a mild progression of muscle weakness. Despite recently identified genetic loci in the AR form, genotype-phenotype correlations are poorly established. Our index case is a 17 year old boy with recessive CNM causing loss of ambulation at 13 years of age and requiring ventilatory assistance nightly. Recent genetic testing revealed a c.1723A > T mutation in the BIN1 gene. The phenotype of the index case contrasts to previously published cases, where recessive CNM patients have lost ambulation in their 20s and have not required ventilatory assistance. The disease severity of our index case, carrying a c.1723A > T mutation, widens the phenotypic spectrum of AR CNM to include earlier loss of ambulation and respiratory failure.
PMCID: PMC2858945  PMID: 20476667
Centronuclear myopathy; BIN1; phenotype
23.  Markers of degeneration and regeneration in Duchenne muscular dystrophy 
Acta Myologica  2009;28(3):94-100.
Summary
Dystrophin deficiency associated with Duchenne muscular dystrophy (DMD) results in chronic inflammation and severe skeletal muscle degeneration, where the extent of muscle fibrosis contributes to disease severity. The microenvironment of dystrophic muscles is associated with variation in levels of markers of degeneration and regeneration. Since in dystrophic muscle apoptosis precedes necrosis, markers of apoptosis can be used as indicators of degeneration, while regeneration can be measured in terms of cytokines and growth factor expression”; and then throughout the text use “markers of apoptosis/degeneration. The present study is an attempt to evaluate the extent of degeneration and regeneration in DMD patient blood. Subjects were 24 boys with DMD diagnosed at the molecular level versus 20 age and socioeconomic matching healthy boys. In their blood, levels of Fas and FasL and Bax/Bcl-2 and plasma DNA fragmentation were measured as markers of apoptosis. The cytokine tumor necrosis factor alfa (TNF-α), and the growth factors: basic fibroblast growth factor (bFGF) and vascular endothelial growth factor (VEGF) were measured as markers of regeneration. Plasma DNA fragmentation (0.38% ± 0.12 vs. 0.2% ± . 0.1.5) and Fas (9.9 ± 2.8 vs. 2 ± 0.1, p < 0.001) together with FasL mRNA expression in circulating lymphocytes (0.47 ± .09 vs. 0.24 ± .04, p < 0.001) were significantly increased in DMD patients compared to controls. There was a significant increase in Bax (0.19 ± 0.7 vs. 0.05 ± 0.1, p < 0.00001) expression and a significant decrease in Bcl-2 protein (6.4 ± 1.6 vs10 ± 2.8, p < 0.00001) as compared to controls. Among markers of regeneration, TNF- α (30.2 ± 9.5 vs. 3.6 ± 0.9) and bFGF (21.7 ± 10.3 vs. 4.75 ± 2.2) were significant increased while VEGF was significantly decreased (190 ± 115 vs. 210 ± 142.) in blood of DMD patients compared to controls. Our results indicate that Fas/FasL and Bax/Bcl-2 are involved in muscle atrophy and degeneration in DMD patients, while regeneration process does not cope with the degeneration.
PMCID: PMC2858946  PMID: 20476668
Apoptosis; basic fibroblast growth factor; Duchenne muscular dystrophy
24.  The progress reports on the development of therapies of Duchenne muscular dystrophy 
Acta Myologica  2009;28(2):62-65.
Summary
The roots of the progress reports on the development of therapies for Duchenne muscular dystrophy (DMD) that since 2000 have been produced at Breitnau/Germany and distributed to the parents of DMD patients cover over 30 years of continual occupation with this disease. The beginning was marked by the development of an early detection programme for the genetic disposition for DMD in infant boys. The next step was the organisation of workshops on the management of DMD and the writing of progress reports on these and other relevant conferences. Getting acquainted with the ideas of the protagonists in the research field by holding interviews was a decisive prerequisite for this activity. This took place in tandem with the development of a new kind of multiplex “family letters” that attempted to answer frequently asked questions to many DMD families at the same time.
When – with the beginning of the new millennium – the endeavours towards gene therapies for DMD started to boom all over the scientific world, progress reports designed to keep the families informed about research on DMD treatment were added to the family letters. These reports that give an account of the latest state of the research are written in a plain language that can be understood by laypersons. In the meantime the reports have adopted the character of reviews that are updated annually. They are written in English and German and translated into Spanish and many other languages.
PMCID: PMC2858951  PMID: 20128138
Duchenne muscular dystrophy; CK screening; multiplex family letters; progress reports; gene therapy; exon skipping
25.  Mild form of Charcot-Marie-Tooth type 1X disease caused by a novel Cys179Gly mutation in the GJB1/Cx32 gene 
Acta Myologica  2009;28(2):72-75.
Summary
Charcot-Marie-Tooth type 1X (CMT1X) disease is inherited as an X-linked dominant trait. Female CMT1X patients are usually mildly affected or even asymptomatic carriers of mutations in the GJB1 gene coding for a gap junction protein called connexin-32 (Cx32).
In this report, a five-generation CMT1X family is described from which the new mutation in the GJB1 gene Cys179Gly was identified.
The Cys179Gly mutation is located in the highly conservative domain of the Cx32 protein. Previous functional studies performed in the oocyte system have shown that point mutations in the highly conserved Cx32 cysteine residues result in a complete loss of function of the gap junction. However, despite severe biochemical defects, the Cys179Gly mutation segregates with a mild CMT1X phenotype.
This study further documents a discrepancy between biochemical effects of GJB1 mutations and the CMT1X phenotype.
PMCID: PMC2858952  PMID: 20128140
CMT1X disease; novel GJB1 gene mutation; Cx32 protein; loss of function mutations

Results 1-25 (72)