The screening for X-linked Emery-Dreifuss muscular dystrophy amongst young patients with idiopathic heart conduction system disease treated by a pacemaker implant.

The X-linked Emery-Dreifuss muscular dystrophy (X-EDMD) is a hereditary muscle disorder associated with cardiac involvement. Sinus node dysfunction and atrioventricular conduction defects, typical of X-EDMD, occur in both males and females and may result in sudden cardiac death unless treated by permanent pacing. The objective of the study was to determine the frequency and relevance of X-EDMD in heart conduction system disease in young individuals treated with a pacemaker implant. The medical history of 3450 paced individuals in the region of South Moravia, Czech republic, was reviewed. Thirty-five patients, 20 males and 15 females, with idiopathic heart conduction disease of onset before age 40 were identified and screened for X-EDMD. Within these 35 individuals, only one male was found to carry a mutation in X-EDMD gene. We conclude that the clinical relevance of X-EDMD in heart conduction system disease is very low. It should, however, be included into the diagnostic work-up of young male individuals with idiopathic cardiac conduction disturbances.

[Disorders of laminins in diseases of myocardial and skeletal muscles]. / Poruchy laminu u postizení srdce a kosterního svalstva.

UNLABELLED: The Emery-Dreifuss muscular dystrophy is caused by muscular lesions and disorders of cardial rhythm and/or by cardiomyopathy. An autosomal dominant form is related to mutations of genes, which are coding for lamins A/C. GROUP AND METHODS: In the group A the authors examined 37 patients with the diagnosis of dilatation cardiomyopathy (DKMP) and the mean ejection fraction 28.4; 8.8%. In the group B of 13 patients a cardiac stimulator was implanted for a rhythm disorder. Both groups were subjected to cardiological, neurological, clinical and electromyographic (EMG) examinations. A muscle biopsy from m. vastus lateralis was made and the sample was evaluated by histology, histochemistry and immunohistochemistry. The coding sequences of genes for lamins were amplified by polymerase chain reaction and the products were analyzed by the DHPLC method (denaturing higher performance liquid chromatography). RESULTS: In the group A there was a clinically myopathic picture in three patients, while EMG examination revealed a myogenic finding in 12 patients and a marginally myogenic one in five patients. The histological finding in 12 patients was evaluated as myogenic and marginally myogenic in six. In one patient the mutation analysis revealed mutation in the gene for lamin A/C. A myogenic finding in this patient was determined by EMG as well as by histological examination and the autosomal dominant form of the Emery-Dreifuss muscular dystrophy was therefore diagnosed. In the group B one patient displayed a myopathic neurological finding and a myogenic finding during EMG. A subsequent mutation analysis revealed a mutation in the gene for lamin A/C. The case was therefore the autosomal dominant form of the Emery-Dreifuss muscular dystrophy. In the other patients the clinically marginal myopathic finding was observed once, a marginally myogenic finding during EMG was seen five times, histology and immunochemistry revealed a myogenic finding once and a marginally myogenic finding also once. The other findings were within normal range. CONCLUSIONS: A careful neurological examination including EMG determined symptoms of skeletal muscle myopathies in a surprisingly high percentage of our cardiological patients. This observation draws attention to the need of neurological examination in patients with DKMP in order to discovered disorder in this area in time. In two patients mutations in genes coding lamins A/C were detected. It would be useful to analyze also genes coding for other cytoskeletal proteins in the future.

A mutation in the X-linked Emery-Dreifuss muscular dystrophy gene in a patient affected with conduction cardiomyopathy.

A screening for mutation in the X-linked Emery-Dreifuss muscular dystrophy (X-EMD) gene was performed among patients affected with severe heart rhythm defects and/or dilated cardiomyopathy. Patients were selected from the database of the Department of Cardiology of the University Hospital Brno. One patient presented a mutation in the X-EMD gene and no emerin in his skeletal muscle. The patient had a severe cardiac disease but a very mild muscle disorder that had not been diagnosed until the mutations was found. This case shows that mutations in X-EMD gene, as it was shown for autosomal-dominant EMD, can cause a predominant cardiac phenotype.

[Muscular dystrophies detected by immunophenotyping and genotype analysis (mRNA and DNA)]. / Svalové dystrofie detekované imunofenotypizací a analýzou genotypu (m-RNA a DNA).

Complex diagnosis of muscular dystrophies including clinical, bioptical and molecular genetic approaches has been provided in a limited extent in this country. Our group of neurologists, pathologists and geneticists has examined approximately 240 patients suspected of having muscular dystrophies, mostly coming from Southern and Northern Moravia. The patients were sent to the examination most often from departments of neurology and clinical genetics, and less frequently from departments of internal medicine. According to the final diagnosis, the patients were divided into groups: with dystrophinopathies and carriers of dystrophinopathies (DMD/BMD), merosin deficient form of congenital muscular dystrophy, and Emery-Dreifuss muscular dystrophy including the carriers of this disease. Some relatives of patients with dystrophinopathies were also examined using the methods of segregation analysis. High proportion of the DMD/BMD patients can be detected by the methods of molecular genetics. Analysis of mRNA using RT PCR and PTT enables the detection of deletions, duplications, and point mutations in dystrophin gene and encompasses a larger diagnostic scope in comparison with examinations of DNA level by the multiplex PCR method from the peripheral blood which enables only deletion detections. Immunophenotyping of the dystrophin protein plays an important role especially using antibodies against carboxyterminal (DYS2) and rod domain (DYS1) of dystrophin. Deficient sarcolemmal expression of DYS2 and DYS1 reveals unambiguously a pathological dystrophin. On the other hand, less pronounced deficiencies in dystrophin expression in BMD patients and DMD/BMD carriers may not always be detected in muscle biopsies. In this case, it is necessary to supplement the examination by Western blotting and genotype analysis. The examination of patients with clinically diagnosed muscular dystrophy should start with a muscle biopsy which enables the estimation of presence and degree of structural changes. Application of antibodies against the components of DGC and emerin may reveal a deficiency in expression of these proteins. Immunohistochemical examination completed by Western blotting leads to the subsequent molecular genetic analysis of DNA or mRNA. Secondary deficiencies in expression of other DGC proteins are often revealed in muscle biopsies of dystrophinopathies and this fact must be taken into account in the evaluation of immunohistochemical findings. There is a possibility of replacement of invasive muscle biopsy by skin biopsy or buccal mucosal smears in cases of merosin and emerin deficiencies. Commercially available antibodies against merosin, emerin, calpain and sarcoglycans enable extensive identification and detailed classification of muscular dystrophies. Screening of the patients based on the application of methods described and discussed in this report is the task of the forthcoming period.

[Deformity of the forearm caused by benign bone tumours treated by external fixation.]. / Deformity predloktí zpusobené benigními kostními nádory, lécení zevním fixátorem.

A developed deformity of the forearm is usually due to an osteochondroma and has a typical clinical and X-ray appearance. Patients suffering from this disease have a restricted function of the forearm due to shortening of the bones, usually both bones, and in particular girls are aware of the cosmetic and aesthetic loss. The X-ray symptomatology of the deformity is as follows: dislocation of the head of the radius, multiple tumours on both bones which dislocate the bones, ulnar angulation of the radius and ulna, shortening of the ulna, ulnar inclination of the articulation surface of the distal radius, ulnar subluxation of the wrist and shortening of the metacarpal bones. The therapeutic procedure used by the authors is stagewise and comprises the following operations: ablation of the osteochondromas, gradual extension of the ulna, reposition of the head of the radius and correction osteotomy of the distal radius. The objective of the submitted paper is long-term clinical and X-ray evaluation of the forearm deformity after operation. In the majority of patients after treatment radial duction in the wrist remains restricted but this is not important from the functional aspect. The X-ray finding of ulnar subluxation of the wrist frequently improves after extension of the ulna. Key words: osteochondromas, deformities of the forearm, gradual extension of the ulna.