Immaturity of muscle fibers in the congenital form of myotonic dystrophy: Its consequences and its origin

Farkas-Bargeton, E.; Barbet, J. P.; Dancea, S.; Wehrlé, Rosine; Checouri, A.; Dulac, Olivier

doi:10.1016/0022-510x(88)90064-0

Cited by 69 publications

(34 citation statements)

References 21 publications

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“…Moreover, an increased cytosolic Ca 2+ concentration [11], altered expression of small conductance Ca 2+ -activated K + channels [12] and a gating abnormality of Na + channels [13,14] could also contribute to the modifications in the excitability in DM1 muscle cells. However, the muscle wasting observed during the progression of the disease and the severe impairment of muscle maturation described in the severe congenital form of DM1 [15,16] cannot be explained by these electrophysiological observations. Muscle biopsies from congenital foetuses display a decreased number of satellite cells (muscle stem cells) [17], and alterations in the behavior of human satellite cells isolated from congenital DM1 patients with a large CTG expansion have been shown in vitro [18,19].…”

Section: Introductionmentioning

confidence: 90%

Potassium currents in human myogenic cells from healthy and congenital myotonic dystrophy foetuses

Nurowska

Constanti²,

Dworakowska

et al. 2009

Cellular and Molecular Biology Letters

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The whole-cell patch clamp technique was used to record potassium currents in in vitro differentiating myoblasts isolated from healthy and myotonic dystrophy type 1 (DM1) foetuses carrying 2000 CTG repeats. The fusion of the DM1 myoblasts was reduced in comparison to that of the control cells. The dystrophic muscle cells expressed less voltage-activated K(+) (delayed rectifier and non-inactivating delayed rectifier) and inward rectifier channels than the age-matched control cells. However, the resting membrane potential was not significantly different between the control and the DM1 cells. After four days in a differentiation medium, the dystrophic cells expressed the fast-inactivating transient outward K(+) channels, which were not observed in healthy cells. We suggest that the low level of potassium currents measured in differentiated DM1 cells could be related to their impaired fusion

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Section: Introductionmentioning

confidence: 90%

Potassium currents in human myogenic cells from healthy and congenital myotonic dystrophy foetuses

Nurowska

Constanti²,

Dworakowska

et al. 2009

Cellular and Molecular Biology Letters

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“…CDM is usually associated with extremely large CTG expansions (Ͼ1500 CTG) and evidence of delayed or arrested muscle maturation. 9,10 Various hypotheses have been proposed to explain how this untranslated CTG repeat causes the multitude of physiopathological features of DM. Experimental support has been produced both for dominant-negative effects of CUG repeats in RNA transcripts and for haploinsufficiency due to reduced expression of DMPK and its neighboring genes.…”

mentioning

confidence: 99%

Changes in Myotonic Dystrophy Protein Kinase Levels and Muscle Development in Congenital Myotonic Dystrophy

Furling

Lam

Agbulut

et al. 2003

The American Journal of Pathology

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Myotonic dystrophy (DM1) is caused by the expansion of a CTG repeat in the noncoding region of a protein kinase, DMPK, expressed in skeletal and cardiac muscles. The aim of the present study was to determine the effects of very large CTG expansions on DMPK expression and skeletal muscle development. In fetuses suffering from the severe congenital form of DM1 with large CTG expansions (1800 to 3700 repeats), the skeletal muscle level of DMPK was reduced to 57% of control levels and a similar reduction was observed in cultured DM1 muscle cells relative to control cultures. These results are consistent with greatly reduced DMPK expression from the mutant allele and normal expression from the unaffected allele in this autosomal dominant disorder. In normal fetuses, DMPK protein levels increased dramatically between 9 and 16 weeks and remained high throughout the remaining gestation period. DM1 fetuses showed impaired skeletal muscle development, characterized by a persistence of embryonic and fetal myosin heavy chains and almost total absence of slow myosin heavy chains at the end of gestation. DMPK expression, however, was similar in both fast and slow fibers from normal adult muscle. The reduced DMPK and the delayed slow fiber maturation in congenital DM1 may be two separate consequences of nuclear retention of DMPK RNA transcripts with expanded CUG repeats.

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“…Therefore, the decrease of grip strength from 9 to 10 in this particular case is not necessary by the negative evidence for an increase of muscle strength in patients with myotonic dystrophy. In the skeletal muscle immature fibers are observed predominantly in childhood in patients with CMyD 23) , but in adults with CMyD pathological observations are similar to those of late onset MyD 24) . Kikuchi and colleagues reported that the muscle pathological observation of CMyD with growth to 10 years old was similar to that of adult onset MyD and type IIC (immature) fibers were not detected 25) .…”

Section: Discussionmentioning

confidence: 51%

The Change of Grip Strength in a Patient with Congenital Myotonic Dystrophy Over a 4-year Period

Kikuchi

Kozuka²,

Uchida

et al. 2008

J Jpn Phys Ther Assoc

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ABSTRACT. Myotonic dystrophy (MyD) is a neuromuscular disease that is autosomal dominant and the most common form of muscular dystrophy affecting adults. The clinical features of MyD include a multisystemic disorder characterized by myotonia, progressive muscle weakness and wasting, cataracts, premature balding and mental retardation. The most severe type of MyD is classified as congenital MyD (CMyD). The muscle weakness in CMyD is very severe, but muscle development can be observed in the period of growth. However, no clinical case of this type has been reported yet. Therefore, we report on a girl with CMyD who had an increase in muscle strength over a four-year period. The girl with CMyD participated in this study from the age of 9 to the age of 12. The measurement of muscle strength was recorded as the maximum score of grip strength with the use of dynamometers. Grip strength was assessed once a year by the same two physical therapists. Grip strength of CMyD for each year was markedly weak when compared with the normal controls, but muscle strength changed within some specific growth areas. The muscle weakness in CMyD was remarkable, but the result showed that specific muscle strength of CMyD in childhood was actually increased.

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Immaturity of muscle fibers in the congenital form of myotonic dystrophy: Its consequences and its origin

Cited by 69 publications

References 21 publications

Potassium currents in human myogenic cells from healthy and congenital myotonic dystrophy foetuses

Potassium currents in human myogenic cells from healthy and congenital myotonic dystrophy foetuses

Changes in Myotonic Dystrophy Protein Kinase Levels and Muscle Development in Congenital Myotonic Dystrophy

The Change of Grip Strength in a Patient with Congenital Myotonic Dystrophy Over a 4-year Period

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