Acta myologica : myopathies and cardiomyopathies : official journal of the Mediterranean Society of Myology最新文献

Mutations in the LMNA gene are associated with a wide spectrum of disease phenotypes, ranging from neuromuscular, cardiac and metabolic disorders to premature aging syndromes. Skeletal muscle involvement may present with different phenotypes: limb-girdle muscular dystrophy type 1B or LMNA-related dystrophy; autosomal dominant Emery-Dreifuss muscular dystrophy; and a congenital form of muscular dystrophy, frequently associated with early onset of arrhythmias. Heart involvement may occur as part of the muscle involvement or independently, regardless of the presence of the myopathy. Notably conduction defects and dilated cardiomyopathy may exist without a muscle disease. This paper will focus on cardiac diseases presenting as the first manifestation of skeletal muscle hereditary disorders such as laminopathies, inspired by two large families with cardiovascular problems long followed by conventional cardiologists who did not suspect a genetic muscle disorder underlying these events. Furthermore it underlines the need for a multidisciplinary approach in these disorders and how the figure of the cardio-myo-geneticist may play a key role in facilitating the diagnostic process, and addressing the adoption of appropriate prevention measures.

Cardiomyopathy associated with dystrophinopathies - Duchenne muscular Dystrophy (DMD), Becker muscular dystrophy (BMD), X-linked dilated cardiomyopathy (XL-CM) and cardiomyopathy of Duchenne/Becker (DMD/BMD carriers - is an almost constant manifestation of these neuromuscular disorders and contribute significantly to their morbidity and mortality. Dystrophinopathic cardiomyopathy is the result of the dystrophin protein deficiency at the myocardium level, parallel to that occurring at the skeletal muscle level. Typically, cardiomyopathy begins as a "presymptomatic" stage in the first decade of life and evolves in a stepwise manner toward an end-stage dilated cardiomyopathy. Nearly complete replacement of the myocardium by fibrous and fatty connective tissue results in an irreversible cardiac failure, characterized by a further reduction of ejection fraction (EF < 30%) and frequent episodes of acute heart failure (HF). The picture of a severe dilated cardiomyopathy with intractable heart failure is typical of dystrophinopathies. Despite an appropriate pharmacological treatment, this condition is irreversible because of the extensive loss of myocites. Heart transplantation is the only curative therapy for patients with end-stage heart failure, who remain symptomatic despite an optimal medical therapy. However there is a reluctance to perform heart transplantation (HT) in these patients due to the scarcity of donors and the concerns that the accompanying myopathy will limit the benefits obtained through this therapeutic option. Therefore the only possibility to ameliorate clinical symptoms, prevent fatal arrhythmias and cardiac death in dystrophinopathic patients could be the implantation of intracardiac device (ICD) or resynchronizing devices with defibrillator (CRT-D). This overview reports the personal series of patients affected by DMD and BMD and DMD carriers who received ICD or CRT-D system, describe the clinical outcomes so far published and discuss pro and cons in the use of such devices.

Spinal-bulbar muscular atrophy (SBMA), is an X-linked motor neuron disease caused by a CAG-repeat expansion in the first exon of the androgen receptor gene (AR) on chromosome X. In SBMA, non-neural clinical phenotype includes disorders of glucose and lipid metabolism. We investigated the prevalence of metabolic syndrome (MS), insulin resistance (IR) and non alcoholic fatty liver disease (NAFLD) in a group of SBMA patients. Forty-seven consecutive patients genetically diagnosed with SBMA underwent biochemical analyses. In 24 patients abdominal sonography examination was performed. Twenty-three (49%) patients had fasting glucose above reference values and 31 (66%) patients had a homeostatic model assessment (HOMA-IR) ≥ 2.6. High levels of total cholesterol were found in 24 (51%) patients, of LDL-cholesterol in 18 (38%) and of triglycerides in 18 (38%). HDL-cholesterol was decreased in 36 (77%) patients. Twenty-four (55%) subjects had 3 or more criteria of MS. A positive correlation (r = 0.52; p < 0.01) was observed between HOMA-IR and AR-CAG repeat length. AST and ALT were above the reference values respectively in 29 (62%) and 18 (38%) patients. At ultrasound examination increased liver echogenicity was found in 22 patients (92 %). In one patient liver cirrhosis was diagnosed. Liver/kidney ratio of grey-scale intensity, a semi-quantitative parameter of severity of steatosis, strongly correlated with BMI (r = 0.68; p < 0.005). Our study shows a high prevalence of IR, MS and NAFLD in SBMA patients, conditions that increase the cardiovascular risk and can lead to serious liver damage, warranting pharmacological and non-pharmacological treatment.