Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0029089 (ophthalmoplegia)
 3,338 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Myosin myopathies comprise a group of inherited diseases caused by mutations in myosin heavy chain (MyHC) genes. Homozygous or compound heterozygous truncating MYH2 mutations have been demonstrated to cause recessive myopathy with ophthalmoplegia, mild-to-moderate muscle weakness and complete lack of type 2A muscle fibers. In this study, we describe for the first time the clinical and morphological characteristics of recessive myosin IIa myopathy associated with MYH2 missense mutations. Seven patients of five different families with a myopathy characterized by ophthalmoplegia and mild-to-moderate muscle weakness were investigated. Muscle biopsy was performed to study morphological changes and MyHC isoform expression. Five of the patients were homozygous for MYH2 missense mutations, one patient was compound heterozygous for a missense and a nonsense mutation and one patient was homozygous for a frame-shift MYH2 mutation. Muscle biopsy demonstrated small or absent type 2A muscle fibers and reduced or absent expression of the corresponding MyHC IIa transcript and protein. We conclude that mild muscle weakness and ophthalmoplegia in combination with muscle biopsy demonstrating small or absent type 2A muscle fibers are the hallmark of recessive myopathy associated with MYH2 mutations.
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PMID:Recessive myosin myopathy with external ophthalmoplegia associated with MYH2 mutations. 2419 43

The term hereditary inclusion-body myopathies (HIBMs) defines a group of rare muscle disorders with autosomal recessive or dominant inheritance and presence of muscle fibers with rimmed vacuoles and collection of cytoplasmic or nuclear 15-21 nm diameter tubulofilaments as revealed by muscle biopsy. The most common form of HIBM is due to mutations of the GNE gene that codes for a rate-limiting enzyme in the sialic acid biosynthetic pathway. This results in abnormal sialylation of glycoproteins that possibly leads to muscle fiber degeneration. Mutations of the valosin containing protein are instead responsible for hereditary inclusion-body myopathy with Paget's disease of the bone and frontotemporal dementia (IBMPFD), with these three phenotypic features having a variable penetrance. IBMPFD probably represents a disorder of abnormal cellular trafficking of proteins and maturation of the autophagosome. HIBM with congenital joint contractures and external ophthalmoplegia is due to mutations of the Myosin Heavy Chain IIa gene that exerts a pathogenic effect through interference with filament assembly or functional defects in ATPase activity. This review illustrates the clinical and pathologic characteristics of HIBMs and the main clues available to date concerning the possible pathogenic mechanisms and therapeutic perspectives of these disorders. This article is part of a Special Issue entitled: Neuromuscular Diseases: Pathology and Molecular Pathogenesis.
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PMID:Hereditary inclusion-body myopathies. 2514 37

Myosin heavy chain (MyHC) is a major structural component of the striated muscle contractile apparatus. In adult human limb skeletal muscle, there are three major MyHC isoforms, slow/beta cardiac MyHC, MyHC IIa and MHC IIx, which are important for the functional characteristics of different muscle fiber types. Hereditary myosin myopathies have emerged as an important group of diseases with variable clinical and morphological expression dependent on the mutated isoform, and also the type and location of the mutation. Myosin myopathy with external ophthalmoplegia is associated with mutations in MYH2, encoding for MyHC IIa that is mainly expressed in type 2A muscle fibers and is inherited in dominant as well as recessive manner. We present a family with myopathy with early onset proximal muscle weakness, facial muscle involvement and ophthalmoplegia. Muscle biopsy demonstrated lack of type 2A muscle fibers and genetic work up demonstrated that the disease was caused by a novel recessive MYH2 mutation: c.1009-1G>A resulting in skipping of exon 12, which is predicted to result in a frame shift and introducing at premature stop codon at position 347 (p.Ser337Leufs*11).
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PMID:A novel MYH2 mutation in family members presenting with congenital myopathy, ophthalmoplegia and facial weakness. 2717 98

A 7-week-old infant presented with persistent noisy breathing and aspirations during swallowing. Neurological examination and brain MRI were normal. His 12-year-old brother underwent pneumonectomy at the age of 10 years due to recurrent aspirations leading to severe lung damage. The older brother developed subsequently ophthalmoplegia and nystagmus along with mild weakness of the neck flexors and proximal muscles. Exome analysis revealed homozygosity for a novel truncating mutation p.G800fs27* in the Myosin Heavy Chain 2 (MYH2) gene in both brothers, while parents and an unaffected sibling were heterozygous. A muscle biopsy from the older brother showed absence of type-2 muscle fibers and predominance of type-1 fibers. The aspirations causing pneumonia likely result from weakness of the laryngeal muscles, normally rich in type-2 fibers. The findings expand the phenotypic spectrum of MYH2 deficiency. MYH2 mutations should be included in the differential diagnosis of infants presenting with recurrent aspirations.
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PMID:Congenital myopathy due to myosin heavy chain 2 mutation presenting as chronic aspiration pneumonia in infancy. 2872 39