Congenital Myopathies

Abstract

Most congenital myopathies have been defined on account of the morphological findings in enzyme histochemical preparations. In effect, the diagnosis of this group of diseases continues to be made on the histological pattern of muscle biopsies. However, progress has been made in elucidating the molecular genetic background of several of the congenital myopathies. In this updated review we address those congenital myopathies for which gene defects and mutant proteins have been found (central core disease, nemaline myopathies, desminopathy, actinopathy, certain vacuolar myopathies, and myotubular myopathy) and the other disease with central nuclei (centronuclear myopathy).

RNA interference screening inDrosophilaprimary cells for genes involved in muscle assembly and maintenance

“…Both congenital myopathies and cardiomyopathies are also called 'sarcomere diseases' (Bornemann and Goebel, 2001;Clarkson et al, 2004;Seidman and Seidman, 2001). Indeed, the primary muscle phenotypes caused by RNAi on the Drosophila homologs of these human disease genes indicate that they are involved in different aspects of sarcomeric organization and muscle maintenance.…”

“…A potential explanation is that these genes, mutations in which are associated with various types of human muscular dystrophies, are required for maintaining muscle strength and integrity (Dalkilic and Kunkel, 2003) (see Table S1 in the supplementary material). This is in contrast to congenital myopathies and cardiomyopathies, which are usually caused by the disruption of genes encoding sarcomeric components (Bornemann and Goebel, 2001;Clarkson et al, 2004;Seidman and Seidman, 2001) (see Table S1 in the supplementary material). Therefore, it is possible that muscles in culture do not experience the same mechanical stress as they do in vivo.…”

Myogenin (Myf4) upregulation in trans-differentiating fibroblasts from a congenital myopathy with arrest of myogenesis and defects of myotube formation

“…Due to this extensive network there are numerous crucial targets for gene mutation and protein failures, which might result in myopathies with their wide variance in clinical manifestation (Bornemann and Goebel 2001). A very early defect of myogenesis has to be assumed in the congenital myopathy described and investigated in this report.…”

“…The histological variety is in accordance with their clinical appearance, which ranges from mild to very severe myopathies with perinatal respiratory failure. Some known causes of myopathies include defects of membranous protein, enzymes or structural proteins (Bornemann and Goebel 2001).…”

Progressive external ophthalmoplegia as initial manifestation of sporadic late-onset nemaline myopathy

“…Serum creatine kinase is usually normal, and electromyography may show myopathic changes. Nemaline rods in affected muscle fibers are considered the histopathological hallmark of nemaline myopathy and are mainly found within the sarcoplasm, inside of myonuclei, or both [3]. Ocular involvement has never been described in a patient with SLONM.…”