| 1. |
- Cuisset, J. M., et al.
(författare)
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'Cap myopathy' : case report of a family
- 2006
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Ingår i: Neuromuscular Disorders. - : Institute of Information Science. - 0960-8966 .- 1873-2364. ; 16:4, s. 277-281
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Tidskriftsartikel (refereegranskat)abstract
- We report the observation of an 18-year-old girl, whose clinical presentation was very suggestive of a congenital myopathy with neonatal onset. A congenital myopathy had been already diagnosed in her brother and in addition her half-cousin died diagnosed with a severe nemaline myopathy at age 4 years. A muscle biopsy performed on both siblings revealed histological and ultrastructural features of 'cap myopathy'. This case report suggests that 'cap myopathy' and some cases of nemaline myopathy with neonatal onset might be two phenotypic expressions of the same genetic disorder. These two entities could therefore, perhaps, be regarded as 'Z-line disorders' possibly caused by defective myofibrillogenesis.
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| 2. |
- Li, Mingxin, et al.
(författare)
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Muscle cell and motor protein function in patients with a IIa myosin missense mutation (Glu-706 to Lys)
- 2006
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Ingår i: Neuromuscular Disorders. - : Elsevier BV. - 0960-8966 .- 1873-2364. ; 16:11, s. 782-791
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Tidskriftsartikel (refereegranskat)abstract
- The pathogenic events leading to the progressive muscle weakness in patients with a E706K mutation in the head of the myosin heavy chain (MyHC) IIa were analyzed at the muscle cell and motor protein levels. Contractile properties were measured in single muscle fiber segments using the skinned fiber preparation and a single muscle fiber in vitro motility assay. A dramatic impairment in the function of the IIa MyHC isoform was observed at the motor protein level. At the single muscle fiber level, on the other hand, a general decrease was observed in the number of preparations where the specific criteria for acceptance were fulfilled irrespective of MyHC isoform expression. Our results provide evidence that the pathogenesis of the MyHC IIa E706K myopathy involves defective function of the mutated myosin as well as alterations in the structural integrity of all muscle cells irrespective of MyHC isoform expression.
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| 3. |
- Ohlsson, M., et al.
(författare)
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Follow-up of nemaline myopathy in two patients with novel mutations in the skeletal muscle alpha-actin gene (ACTA1)
- 2004
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Ingår i: Neuromuscular Disorders. - : Institute of Information Science. - 0960-8966 .- 1873-2364. ; 14:8-9, s. 471-475
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Tidskriftsartikel (refereegranskat)abstract
- Nemaline myopathy has been associated with mutations in five different genes, which all encode protein components of the sarcomeric thin filaments. We report follow-up studies in two children with mutations not previously described in skeletal muscle alpha-actin (ACTA1). Case 1 was a male patient who after birth suffered from pronounced muscle weakness and hypotonia. Muscle biopsy showed small fibers with numerous rods. He failed to achieve any motor milestones. At the age of 17 he required 24 h ventilator support. He could not lift his arms against gravity, but he could use his hands to control his electric wheelchair. The muscle biopsy showed marked replacement of muscle tissue by fat and connective tissue. Only few fibers showed nemaline rods. He had a de novo, heterozygous mutation, G268D in ACTA1. Case 2 was a female patient with feeding difficulties and mild hypotonia in the neonatal period. Muscle biopsy showed hypoplastic muscle fibers and numerous rods. At 11 years of age she walked and moved unhindered and could run fairly well. She had a de novo, heterozygous mutation, K373E, in ACTA1. These two patients illustrate the marked variability in the clinical features of nemaline myopathy in spite of similar muscle pathology in early childhood. The severe muscle atrophy with replacement of fat and connective tissue in case 1 demonstrates the progressive nature of nemaline myopathy in some cases. The described two mutations add to the previously reported mutations in ACTA1 associated with nemaline myopathy.
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| 4. |
- Tajsharghi, Homa, et al.
(författare)
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Early onset myopathy with a novel mutation in the Selenoprotein N gene (SEPN1)
- 2005
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Ingår i: Neuromuscular Disorders. - : Elsevier. - 0960-8966 .- 1873-2364. ; 15:4, s. 299-302
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Tidskriftsartikel (refereegranskat)abstract
- Mutations in SEPN1 have been associated with three autosomal recessive congenital myopathies, including rigid spine muscular dystrophy, multiminicore disease and desmin-related myopathy with Mallory body-like inclusions. These disorders constitute the SEPN1 related myopathies (SEPN-RM). On the basis of clinical and laboratory features compatible with SEPN-RM, we performed mutation analysis of SEPN1 in 11 unrelated patients and found one case with pathogenic mutations. He showed early onset axial muscle weakness and developed scoliosis with respiratory insufficiency. Muscle biopsy showed increased variability of fiber size and slight, focal increase of connective tissue. A few fibers showed mini-core changes. SEPN1 mutation analysis revealed that the patient was a compound heterozygote: a previously described insertion (713-714 insA), and a novel nonsense mutation (R439stop).
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| 5. |
- Tajsharghi, Homa, et al.
(författare)
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Myopathies associated with β-tropomyosin mutations
- 2012
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Ingår i: Neuromuscular Disorders. - : Elsevier. - 0960-8966 .- 1873-2364. ; 22:11, s. 923-933
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Forskningsöversikt (refereegranskat)abstract
- Mutations in TPM2, encoding β-tropomyosin, have recently been found to cause a range of muscle disorders. We review the clinical and morphological expression of the previously reported mutations illustrating the heterogeneity of β-tropomyosin-associated diseases and describe an additional case with a novel mutation. The manifestations of mutations in TPM2 include non-specific congenital myopathy with type 1 fibre predominance, nemaline myopathy, cap disease and distal arthrogryposis. In addition, Escobar syndrome with nemaline myopathy is a manifestation of homozygous truncating β-tropomyosin mutation. Cap disease appears to be the most common morphological manifestation. A coarse intermyofibrillar network and jagged Z lines are additional frequent changes. The dominant β-tropomyosin mutations manifest either as congenital myopathy or distal arthrogryposis. The various congenital myopathies are usually associated with moderate muscle weakness and no congenital joint contractures. The distal arthrogryposis syndromes associated with TPM2 mutations include the less severe forms, with congenital contractures mainly of the hands and feet and mild or no muscle weakness. The dominant TPM2 mutations include amino acid deletions/insertions and missense mutations. There is no clear relation between the type of mutations or the localisation of the mutated residue in the β-tropomyosin molecule and the clinical and morphological phenotype.
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| 6. |
- Tajsharghi, Homa, et al.
(författare)
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Myosin storage myopathy with cardiomyopathy
- 2007
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Ingår i: Neuromuscular Disorders. - : Institute of Information Science. - 0960-8966 .- 1873-2364. ; 17:9-10, s. 725-
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Tidskriftsartikel (refereegranskat)
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