0000000000173043
AUTHOR
Marianne De Visser
Whole Exome Sequencing Is the Preferred Strategy to Identify the Genetic Defect in Patients With a Probable or Possible Mitochondrial Cause
Mitochondrial disorders, characterized by clinical symptoms and/or OXPHOS deficiencies, are caused by pathogenic variants in mitochondrial genes. However, pathogenic variants in some of these genes can lead to clinical manifestations which overlap with other neuromuscular diseases, which can be caused by pathogenic variants in non-mitochondrial genes as well. Mitochondrial pathogenic variants can be found in the mitochondrial DNA (mtDNA) or in any of the 1,500 nuclear genes with a mitochondrial function. We have performed a two-step next-generation sequencing approach in a cohort of 117 patients, mostly children, in whom a mitochondrial disease-cause could likely or possibly explain the phe…
Mutations in the β-tropomyosin (TPM2) gene – a rare cause of nemaline myopathy
Nemaline myopathy is a clinically and genetically heterogeneous muscle disorder. In the nebulin gene we have detected a number of autosomal recessive mutations. Both autosomal dominant and recessive mutations have been detected in the genes for alpha -actin and alpha -tropomyosin 3. A recessive mutation causing nemaline myopathy among the Old Order Amish has recently been identified in the gene for slow skeletal muscle troponin T. As linkage studies had shown that at least one further gene exists for nemaline myopathy, we investigated another tropomyosin gene expressed in skeletal muscle, the beta -tropomyosin 2 gene. Screening 66 unrelated patients, using single strand conformation polymor…
205th ENMC International Workshop: Pathology diagnosis of idiopathic inflammatory myopathies Part II 28-30 March 2014, Naarden, The Netherlands.
The idiopathic inflammatory myopathies (IM) are a heterogeneous group of diseases and diagnosis often necessitates a muscle biopsy. Five main entities are recognized: (1) dermatomyositis (DM); (2) polymyositis (PM); (3) necrotizing autoimmune myopathy (NAM); (4) sporadic inclusion body myositis (IBM); and (5) non-specific myositis. Other entities include granulomatous myopathy, macrophagic myofasciitis, and eosinophilic fasciitis (Shulman's syndrome). The pathological classification and subsequent identification of disease subgroups are extremely important for assessing treatment options and prognosis in the individual patient, yet classification criteria have not been standardized and vali…