The presence of non-progressive cognitive impairment is recognized as a common feature in a substantial proportion of patients with Duchenne muscular dystrophy (DMD). Concurrently, the amyloid beta peptide (Aβ42) protein has been associated with changes in memory and cognitive functions. Also, it has been shown that different subtypes of neural stem/progenitor cells (CD 34, CD 45, nestin) are involved in the innate repair of plasticity mechanisms by the injured brain, in which Nerve Growth Factor (NGF) acts as chemotactic agents to recruit such cells. Accordingly, the present study investigated levels of CD 34, CD 45, nestin and NGF in an attempt to investigate makers of neural regeneration in DMD. Neural damage was assayed in terms of Aβ42. Results showed that Aβ42 (21.9 ± 6.7 vs. 12.13 ± 4.5) was significantly increased among DMD patients compared to controls. NGF (165.8 ± 72 vs. 89.8 ± 35.9) and mononuclear cells expressing nestin (18.9 ± 6 vs. 9 ± 4), CD 45 (64 ± 5.4 vs. 53.3 ± 5.2) and CD34 (75 ± 6.2 vs. 60 ± 4.8) were significantly increased among DMD patients compared to controls. In conclusion cognitive function decline in DMD patients is associated with increased levels of Aβ42, which is suggested to be the cause of brain damage in such patients. The significant increase plasma NFG and in the number of mononuclear cells bearing CD34, CD45 and nestin indicates that regeneration is an ongoing process in these patients. However, this regeneration cannot counterbalance the damage induced by dystrophine mutation and increased Aβ42.
Duchenne muscular dystrophy; neural damage; cognitive
Limb-girdle muscular dystrophies (LGMD) are a highly heterogeneous group of muscle disorders, which first affect the voluntary muscles of the hip and shoulder areas. The definition is highly descriptive and less ambiguous by exclusion: non-Xlinked, non-FSH, non-myotonic, non-distal, nonsyndromic, and non-congenital. At present, the genetic classification is becoming too complex, since the acronym LGMD has also been used for a number of other myopathic disorders with overlapping phenotypes. Today, the list of genes to be screened is too large for the gene-by-gene approach and it is well suited for targeted next generation sequencing (NGS) panels that should include any gene that has been so far associated with a clinical picture of LGMD. The present review has the aim of recapitulating the genetic basis of LGMD ordering and of proposing a nomenclature for the orphan forms. This is useful given the pace of new discoveries. Thity-one loci have been identified so far, eight autosomal dominant and 23 autosomal recessive. The dominant forms (LGMD1) are: LGMD1A (myotilin), LGMD1B (lamin A/C), LGMD1C (caveolin 3), LGMD1D (DNAJB6), LGMD1E (desmin), LGMD1F (transportin 3), LGMD1G (HNRPDL), LGMD1H (chr. 3). The autosomal recessive forms (LGMD2) are: LGMD2A (calpain 3), LGMD2B (dysferlin), LGMD2C (γ sarcoglycan), LGMD2D (α sarcoglycan), LGMD2E (β sarcoglycan), LGMD2F (δ sarcoglycan), LGMD2G (telethonin), LGMD2H (TRIM32), LGMD2I (FKRP), LGMD2J (titin), LGMD2K (POMT1), LGMD2L (anoctamin 5), LGMD2M (fukutin), LGMD2N (POMT2), LGMD2O (POMTnG1), LGMD2P (dystroglycan), LGMD2Q (plectin), LGMD2R (desmin), LGMD2S (TRAPPC11), LGMD2T (GMPPB), LGMD2U (ISPD), LGMD2V (Glucosidase, alpha ), LGMD2W (PINCH2).
Limb-girdle muscular dystrophies; LGMD; NGS
We studied the consequences of the Nav1.4 mutation R1448H that is situated in the fourth voltage sensor of the channel and causes paramyotonia, a cold-induced myotonia followed by weakness. Previous work showed that the mutation uncouples inactivation from activation. We measured whole-cell Na+ currents at 10, 15, 20, and 25°C using HEK293 cells stably transfected with wildtype (WT) and R1448H Na+ channels. A Markov model was developed the parameters of which reproduced the data measured on WT and R1448H channels in the whole voltage and temperature range. It required an additional transient inactivated state and an additional closed-state inactivation transition not previously described. The model was used to predict single-channel properties, free energy barriers and temperature dependence of rates. It allowed us to draw the following conclusions: i) open-state inactivation results from a two-step process; ii) the channel re-openings that cause paramyotonia originate from enhanced deactivation/reactivation and not from destabilized inactivation; iii) the closed-state inactivation of R1448H is strikingly enhanced. We assume that latter explains the episodic weakness following cold-induced myotonia.
Paramyotonia; markov model; sodium channel; closed-state inactivation; channelopathy; skeletal muscle
This article shortly examines the biography, scientific activity and scientific work on neuromuscular diseases of the famous Russian neurologist Vladimir Roth who was the founder of neuromuscular disorders study in Russia. In 1876 he was the first in Russia who performed an autopsy and a detailed histological study of a case of progressive muscular atrophy, in which he did not find changes in the nervous system. He called this disease "muscular tabes" i.e. myopathy. In 1884 Vladimir Roth expressed his opinion about the nosological place of the peripheral type of muscular tabes to be considered as a distal myopathy. Dr. Roth became well-known for his monograph of the neuromuscular diseases, published in Moscow in 1895 under the name "Muscular Tabes" in which he described the history of neuromuscular diseases in a very detailed way, analyzing 1014 cases published in the world literature from 1830 to 1893 and 125 personal observations in the period 1874-1894. He performed a thorough analysis of the pattern of muscle involvement using both electrodiagnostic and histological study of muscles and central/peripheral nervous system. We report a short review of this monograph and two cases of peripheral (distal) myopathy.
Muscular tabes; distal myopathy; peripheral neuromuscular involvement
Because I am a neuromyologist that has dealt for many years with muscle hypertonia, I decided to write my memories in order to motivate younger researchers to try to duplicate the same observations and experiences.
We defined a whole range of conditions and symptoms, partly or in full. That is the first crucial step on the way to suppressing or relieving suffering. In some cases there was nothing we could do. In the other cases, we managed to diminish the uncomfortable symptoms. In still other cases, we cured the diseases, at least for a while. My conclusion is that great and systematic effort is always worth the trial. Maybe someone will follow us?!
Always again, I used to repeat to myself and to the others that, when approaching the patient, always the following rules should be respected: watch, listen and use your own common sense to evaluate what you observe; analyse why the symptoms occur in a concrete case; include the therapy in the logic of symptom development; continue to follow the patient and ask questions of yourself and of your colleagues; consult the literature; find the differences; ask again and again what else could be done ... and the solutions will appear unexpectedly.
Spasticity; cramps; neuromyotony
It is not known whether eosinophilic myositis is a specific histopathological feature of limb girdle muscular dystrophy 2A (LGMD2A).
Number and location of eosinophils in skeletal muscle biopsies (n=100) was analysed by Giemsa and modified hematoxylin/eosin staining in patients with genetically confirmed myopathies (LGMD2A, LGMD2B, LGMD2L, facioscapulohumeral muscular dystrophy, dystrophinopathy), histologically confirmed idiopathic inflammatory myopathies (sporadic inclusion body myositis (sIBM), dermatomyositis (DM), polymyositis), amyotrophic lateral sclerosis (neurogenic control), and normal controls.
The number of eosinophils/mm2 was significantly higher in LGMD2A, PM, DM, and sIBM compared to controls but not significantly higher than other myopathies. A large overlap in the number of eosinophils/mm2 between all groups was seen. In all disease groups eosinophils were mainly found endomysially (46- 88%) and intra- and perivascularly (4-37%). There was no correlation between the numbers of eosinophils/mm2 and (i) age at biopsy and (ii) the duration of the disease. The extent of myopathic, fibrotic, and inflammatory changes did not differ in samples with high and low eosinophil count.
Eosinophils seem to represent an unspecific histological finding in hereditary and inflammatory myopathies, but also amyotrophic lateral sclerosis.
Eosinophil; inflammatory myopathy; hereditary myopathy; limb girdle muscular dystrophy; calpainopathy; Giemsa staining; amyotrophic lateral sclerosis
Myotonic dystrophy (DM) is the most common adult muscular dystrophy, characterized by autosomal dominant progressive myopathy, myotonia and multiorgan involvement. To date two distinct forms caused by similar mutations have been identified. Myotonic dystrophy type 1 (DM1, Steinert's disease) was described more than 100 years ago and is caused by a (CTG)n expansion in DMPK, while myotonic dystrophy type 2 (DM2) was identified only 18 years ago and is caused by a (CCTG)n expansion in ZNF9/CNBP. When transcribed into CUG/CCUG-containing RNA, mutant transcripts aggregate as nuclear foci that sequester RNA-binding proteins, resulting in spliceopathy of downstream effector genes. Despite clinical and genetic similarities, DM1 and DM2 are distinct disorders requiring different diagnostic and management strategies. DM1 may present in four different forms: congenital, early childhood, adult onset and late-onset oligosymptomatic DM1. Congenital DM1 is the most severe form of DM characterized by extreme muscle weakness and mental retardation. In DM2 the clinical phenotype is extremely variable and there are no distinct clinical subgroups. Congenital and childhood-onset forms are not present in DM2 and, in contrast to DM1, myotonia may be absent even on EMG. Due to the lack of awareness of the disease among clinicians, DM2 remains largely underdiagnosed. The delay in receiving the correct diagnosis after onset of first symptoms is very long in DM: on average more than 5 years for DM1 and more than 14 years for DM2 patients. The long delay in the diagnosis of DM causes unnecessary problems for the patients to manage their lives and anguish with uncertainty of prognosis and treatment.
Myotonic dystrophy type 1 (Dm1); myotonic dystrophy type 2 (Dm2); management
The Mediterranean countries are distinguished with their peculiar genetic pool and diversities. Recessive diseases often present with their own founder mutations. In some instances this is shared with neighboring populations. Dominant disorders in the area are increasingly recognized as health care providing systems and technology improve. Among muscular dystrophies Duchenne and Becker types constitute the major fraction in almost all societies. This is followed by various forms of limb-girdle muscular dystrophy. Congenital dystrophies and other related rare types are a matter of recognition. The identification and registry of facio-scapulo-humeral and myotonic dystrophies vary in different states.
Frequency; incidence; muscular dystrophies; Mediterranean area
The role that atrial pacing therapy plays on the atrial fibrillation (AF) burden is still unclear. Aim of the study was to evaluate the effect of the atrial preference pacing algorithm on AF burden in patients affected by Myotonic Dystrophy type 1 (DM1) followed for a long follow up period. Sixty DM1 patients were -implanted with a dual chamber pacemaker (PM) for first degree or symptomatic type 1/type 2 second degree atrio-ventricular blocks- were followed for 2-years after implantation, by periodical examination. After 1 month of stabilization, they were randomized into two groups: 1) Patients implanted with conventional dual-chamber pacing mode (DDDR group) and 2) Patients implanted with DDDR plus Atrial Preference Pacing (APP) algorithm (APP ON group).
The results showed that atrial tachycardia (AT)/AF burden was significantly reduced at 1 year follow up in the APP ON group (2122 ± 428 minutes vs 4127 ± 388 minutes, P = 0.03), with a further reduction at the end of the 2 year follow up period (4652 ± 348 minutes vs 7564 ± 638 minutes, P = 0.005).
The data here reported show that the APP is an efficient algorithm to reduce AT/AF burden in DM1 patients implanted with dual chamber pacemaker.
Atrial overdrive algorithm; atrial preference pacing; supraventricular tachyarrhythmias; Myotonic Dystrophy type 1
Patients with muscle pathology are a challenge for anaesthesiologists because of possible life-threatening general anaesthesia complications. A review of the current medical literature on the issue clearly indicates that increasing awareness by anaesthesiologists in recent years has led to a reduction in the occurrence of adverse events in patients with diagnostically well-defined muscle disease. On the other hand, the current emerging aspect is that the great majority of complications concern subjects with clinically non-overt (silent to mildly symptomatic) and thus undiagnosed myopathy. With a view to improving prevention of possible critical anaesthesia complications in such patients, we present a "Safe Anaesthesia Table", listing both the anaesthetic drugs to be avoided and those considered harmless for myopathic patients, irrespective of age and type of pathology. In addition, a brief outline about the clinical aspects suggestive of a possible muscle pathology is also provided. Using "safe drugs" during routine surgical procedures in subjects with suspected undiagnosed myopathy will enable the anaesthesiologist to avoid delaying surgery, while protecting them from anaesthesia complications. By following this approach the presumed myopathy can be properly investigated after surgery.
anaesthesia complications; undiagnosed myopathy; safe anaesthesia; hyperCKemia
Glycogen-storage disease type II, also named Pompe disease, is caused by the deficiency of the enzyme acid alpha-glucosidase, which originates lysosomal glycogen accumulation leading to progressive neuromuscular damage. Early-onset Pompe disease shows a debilitating and frequently fulminating course. To date, more than 300 mutations have been described; the majority of them are unique to each affected individual. Most early-onset phenotypes are associated with frameshift mutations leading to a truncated alpha-glucosidase protein with loss of function. Founder effects are responsible from many cases from few highprevalence world regions. Herein we described two apparently unrelated cases affected with classical early-onset Pompe disease, both pertaining to a small region from Central Mexico (the State of San Luis Potosí), the same novel homozygous frameshift mutation at gene GAA (c.1987delC) was demonstrated in both cases. This GAA gene deletion implies a change of glutamine to serine at codon 663, and a new reading frame that ends after 33 base pairs, which leads to the translation of a truncated protein. This report contributes to widen the knowledge on the effect of pathogenic mutations in Pompe disease. Here we postulate the existence of a founder effect.
Early-onset Pompe disease; Acid maltase deficiency; Founder effect
Glycogen storage disease type II - also called Pompe disease or acid maltase deficiency - is an autosomal recessive metabolic disorder, caused by an accumulation of glycogen in the lysosome due to deficiency of the lysosomal acid alpha-glucosidase enzyme. Pompe disease is transmitted as an autosomal recessive trait and is caused by mutations in the gene encoding the acid α-glucosidase (GAA), located on chromosome 17q25.2-q25.3. The different disease phenotypes are related to the levels of residual GAA activity in muscles. The clinical spectrum ranging from the classical form with early onset and severe phenotype to not-classical form with later onset and milder phenotype is described.
Glycogen storage disease type II; Pompe disease; GAA activity
Glycogenosis II (GSD II) is an autosomal recessive lysosomal storage disorder resulting from acid alpha-glucosidase deficiency, subsequent accumulation of glycogen in tissues, impairment of autophagic processes and progressive cardiac, motor and respiratory failure.
The late-onset form is characterized by wide variability in residual enzyme activity, age of onset, rate of disease progression and phenotypical spectrum. Although the pathological process mainly affects the skeletal muscle, several other tissues may be involved in the course of the disease; therefore GSD II should be regarded as a multisystem disorder in which glycogen accumulation is present in skeletal and smooth muscle, heart, brain, liver, spleen, salivary glands, kidney and blood vessels.
In this review, we briefly summarize the main non-muscle targets of the pathological process in late-onset GSD II.
Further studies aimed at evaluating the extra-muscle involvement in this group of patients will help to better define clinical features and prognostic factors and to delineate the natural history of the disease.
Glycogenosis II; GSDII; Pompe disease
Mutations on the LMNA gene are responsible for an heterogeneous group of diseases. Overlapping syndromes related to LMNA gene alterations have been extensively reported. Study scope is to perform a systematic analysis of the overlapping syndromes so far described and to try to correlate the clinical features to the associated genetic alterations. We evaluated all the dominant overlapping syndromes reported by means of a PubMed search and by the analysis of the main databases containing the pathogenic LMNA gene variations and the associated diseases.
Metabolic alterations in association to skeletal and/or cardiac alterations proved to be the most frequent overlap syndrome. Overlapping syndromes are mostly associated to inframe mutations in exons 1, 2, 8 and 9. These data further improve the understanding of the pathogenesis of laminopathies.
Lamin A/C; laminopathies; LMNA overlapping syndromes
Myotonic dystrophy (Dystrophia Myotonica, DM) is the most frequently inherited neuromuscular disease of adult life. It is a multisystemic disease with major cardiac involvement. Core features of myotonic dystrophy are myotonia, muscle weakness, cataract, respiratory failure and cardiac conduction abnormalities. Classical DM, first described by Steinert and called Steinert's disease or DM1 (Dystrophia Myotonica type 1) has been identified as an autosomal dominant disorder associated with the presence of an abnormal expansion of a CTG trinucleotide repeat in the 3' untranslated region of DMPK gene on chromosome 19. This review will mainly focus on the various aspects of cardiac involvement in DM1 patients and the current role of cardiac pacing in their treatment.
myotonic dystrophy type 1; arrhythmias; cardiac pacing
Duchenne muscular dystrophy (DMD) is a disease linked to the X-chromosome which affects 1 in 3,600-6,000 newborn males. It is manifested by the absence of the dystrophin protein in muscle fibres, which causes progressive damage leading to death in the third decade of life. The only medication so far shown to be effective in delaying the progression of this illness are corticosteroids, which have been shown to increase muscle strength in randomised controlled studies; long-term studies have demonstrated that they prolong walking time and retard the progression of respiratory dysfunction, dilated cardiomyopathy and scoliosis. Several potential drugs are now being investigated. Genetic therapy, involving the insertion of a dystrophin gene through a vector, has proven effective in animals but not humans. Currently under clinical study is Ataluren, a molecule that binds with ribosomes and may allow the insertion of an aminoacid in the premature termination codon, and exon-skipping, which binds with RNA and excludes specific sites of RNA splicing, producing a dystrophin that is smaller but functional. There are also studies attempting to modulate other muscular proteins, such as myostatin and utrophin, to reduce symptoms. This paper does not address cardiomyopathy treatment in DMD patients.
Duchenne muscular dystrophy; drug treatment; clinical
Cardiomyopathy is an almost universal finding in boys affected by Duchenne muscular dystrophy (DMD). Myocardial changes, as a result of the lack of dystrophin, consist of cell membrane degradation, interstitial inflammation, fatty replacement and fibrosis.
Dystrophinopathic cardiomyopathy generally starts as a preclinical or intermediate stage, with evolution toward advanced stages characterized by ventricle enlargement but also by symptoms and signs of heart failure (dyspnoea, peripheral edema and liver enlargement). However in few patients the dilation could be the first manifestation of the heart involvement.
The ability to detect overt cardiomyopathy increases with age, such that more than 80% of boys older than 18 years will have abnormal systolic function.
Several drugs have been employed with the aim to contrast the evolution of cardiomyopathy toward stages of severe congestive heart failure. A review of cardiac treatment in DMD and personal experience are reported and discussed.
Dystrophinopathic cardiomyopathy; deflazacort; ACE-inhibitors
In 1988, we familiarised ourselves at Poitiers with the concept of operative treatment of the lower limbs and the spine in Duchenne muscular dystrophy (DMD) patients which Yves Rideau and his collaborators (1, 2) had developed there in the early 1980s. Thereupon, we immediately established the techniques at our home universities, first at the Technische Universität Aachen and, from 1999 on, at the Universitätsklinikum Erlangen, Germany. Since then, we have applied the technique to more than 500 DMD patients in total by performing more than 800 operations on the lower limbs and/or spine. In support of findings reported by Professor Rideau in this issue (3) we observed that, where patients are still ambulatory at the time of operation, the operation delays the point at which patients become wheelchair-bound by about two years. Likewise, patients receiving this treatment were/are also able to perform the Gowers' manoeuvre for around two years longer (4-6).
Duchenne muscular dystrophy; prophylactic surgery; prevention of scoliosis
Recently we reported a cytoplasmic sodium overload to cause a severe osmotic oedema in Duchenne muscular dystrophy (DMD). Our results suggested that this dual overload of sodium ions and water precedes the dystrophic process and persists until fatty muscle degeneration is complete. The present paper addresses the questions as to whether these overloads are important for the pathogenesis of the disease, and if so, whether they can be treated. As a first step, we investigated the effects of various diuretic drugs on a cell model of DMD, i.e. rat diaphragm strips previously exposed to amphotericin B. We found that both carbonic anhydrase inhibitors and aldosterone antagonists were able to repolarise depolarised muscle fibres. Since carbonic anhydrase inhibitors are known to have acidifying effects and this might be detrimental to the ventilation of DMD patients, we mainly concentrated on the modern spironolactone derivative, eplerenone. This drug had a very high repolarizing power, the parameter considered by us as being most relevant for a beneficial effect. In a pilot study we administered this drug to a 22-yr-old female DMD patient who was bound to an electric wheelchair and has had no corticosteroid therapy before. Eplerenone decreased both cytoplasmic sodium and water overload and increased muscle strength and mobility. We conclude that eplerenone has beneficial effects on DMD muscle. In our opinion the cytoplasmic oedema is cytotoxic and should be treated before fatty degeneration takes place.
Duchenne muscular dystrophy; eplerenone; cytotoxic oedema
Duchenne muscular dystrophy is a lethal X-linked muscle disease affecting 1/3500 live male birth. It results from defects in the subsarcolemmal protein dystrophin, a component of the dystrophinglycoprotein complex (DGC) which links the intracellular cytoskeleton to the extracellular matrix. The absence of dystrophin leads to muscle membrane fragility, muscle necrosis and gradual replacement of skeletal muscle by fat and connective tissue, through a complex and still unclear cascade of interconnecting events. No cure is currently available, with glucocorticoids being the sole drugs in clinical use in spite of their remarkable side effects. A great effort is devoted at performing pre-clinical tests on the mdx mouse, the mostly used homologous animal model for DMD, with the final aim to identify drugs safer than steroids and able to target the pathogenic mechanisms so to delay pathology progression. This review updates the efforts on this topic, focusing on the open issues about the animal model and highlighting the classes of pharmaceuticals that are more promising as diseasemodifiers, while awaiting for more corrective therapies. Although caution is necessary in data transfer from mdx model to DMD patients, the implementation of standard operating procedures and the growing understanding of the pathology may allow a more accurate evaluation of therapeutics, alone or in combination, in pre-clinical settings. A continuous cross-talk with clinicians and patients associations are also crucial points for proper translation of data from mouse to bedside.
Duchenne muscular dystrophy; mdx mouse model; pharmaceuticals; pre-clinical studies; translational research
Steroids have been used since two decades and several trials were conducted to establish their efficacy in DMD patients with various regimens. The clinical outcomes showed increased function in the treated boys, and in a single trial with deflazacort, prolongation of ambulation but with different side effects. Steroids clinical efficacy is now established. The main concern is to increase steroid efficacy and decrease side effect and toxicity. A trial comparing daily prednisone, deflazacort and intermittent glucocorticoids (prednisone 10 days on/10 days off) (FOR-DMD) is starting under NIH grant. The primary outcomes will be muscle strength, forced vital capacity and patient/parents satisfaction.
Steroids; Duchenne; DMD; side effect; quality of life
Deflazacort is the most commonly prescribed corticosteroid for the treatment of Duchenne muscular dystrophy in Canada. We review the long term experience with deflazacort treatment at two centers in Canada; Montreal and Toronto. Deflazacort has benefitted both cohorts by prolonged ambulation, preserved cardiac and respiratory function, less scoliosis and improved survival. Common side effects in both cohorts include weight gain, decreased height and cataract formation. The Canadian experience supports the use of deflazacort in treating boys with Duchenne muscular dystrophy.
Deflazacort; Duchenne Muscular Dystrophy; Canada
Pompe disease is caused by glycogen accumulation due to a deficiency of the lysosomal acid alpha-glucosidase enzyme by which it is degraded. It is a rare disease, accounting for 1:40.000 births. It is inherited as an autosomal recessive trait so that a couple presents a recurrent risk of 25% to have a child affected, at each pregnancy. The diagnosis could be achieved by biochemical and/ or molecular testing. Carrier detection and prenatal diagnosis are available when the molecular defect is known.
Pompe disease; genetic counselling; prenatal diagnosis
The spinal muscular atrophies (SMAs) include a group of disorders characterized by progressive weakness of the lower motor neurons. Several types of SMAs have been described based on age onset of clinical features: Acute infantile (SMA type I), chronic infantile (SMA type II), chronic juvenile (SMA type III), and adult onset (SMA type IV) forms. The incidence is about 1:6,000 live births with a carrier frequency of 1:40 for the severe form and 1:80 for the juvenile form. The mortality and/or morbidity rates of SMAs are inversely correlated with the age at onset. SMAs are believed to only affect skeletal muscles; however, new data on SMA mice models suggest they may also impact the heart.
Aim of the study was to retrospectively examine the cardiological records of 37 type molecularly confirmed II/III SMA patients, aged 6 to 65 years, in order to evaluate the onset and evolution of the cardiac involvement in these disorders. All patients had a standard ECG and a routine echocardiography. The parameters analysed were the following: Heart rate (HR), PQ interval, PQ segment, Cardiomyopathic Index (ratio QT/PQs), ventricular and supraventricular ectopic beats, pauses ≥ 2,5msec, ventricle diameters, wall and septum thickness, ejection fraction, fiber shortening.
The results showed that HR and the other ECG parameters were within the normal limits except for the Cardiomyopathic Index that was higher than the normal values (2,6-4,2) in 2 patients. Left ventricular systolic function was within the normal limits in all patients. A dilation of the left ventricle without systolic dysfunction was observed in only 2 patients, aged respectively 65 and 63 years; however they were hypertensive and/or affected by coronary artery disease. Data here reported contribute to reassure patients and their clinicians that type II/III SMAs do not present heart dysfunction.
Spinal Muscular Atrophies; heart involvement; cardiomyopathy
Amyotrophic lateral sclerosis is a fatal neurodegenerative disease of the upper and lower motor neuron of unknown etiology. Although a familial cause for this disease has been suspected early one, it is only in the past two decades that advances in modern genetics led to the identification of more than 10 genes linked to familial ALS and helped us understand some of the complex genetic and environmental interactions that may contribute to sporadic ALS. In this article, we chronologically summarize the genetic breakthroughs in familial and sporadic ALS and depict how it shaped our understanding of disease pathogenesis and our quest for rational therapies.
ALS; SOD1; GWAS