Titre :
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Molecular genetic experience of spinal muscular atrophy (abstract : congrès international de Myologie, 2005)
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contenu dans :
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Auteurs :
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Congrès international de myologie 2005 (International Congress of Myology 2005; 9-13 mai 2005; Nantes, France) ;
Maamouri W ;
Amouri R ;
Hentati F
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Type de document :
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Article
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Année de publication :
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2005
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Pages :
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p. 199
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Langues:
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Anglais
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Mots-clés :
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amyotrophie spinale
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biopsie musculaire
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colloque
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exon
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fibre musculaire striée
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gène SMN2
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génétique moléculaire
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muscle squelettique
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Tunisie
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Résumé :
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Communication n° 530 Background: Proximal spinal muscular atrophy (SMA) is an autosomal recessive neuromuscular disorder that results in loss of motoneurones in the spinal cord. SMA is classified into three groups depending on age of onset and severity. Type I SMA is the most severe, with onset occurring before the age of 6 months and death before the age of two. Type II SMA is of intermediate severity, patients live past the age of two and are able to sit but never gain the ability to walk. Type III SMA, onset of symptoms occurs after the age of 18 months and patients may be ambulatory for long periods in their lives. Adult form Type IV is the mildest, with onset after 30 years of age. SMA of all three types is associated in 96% with deletion of exon 7 of the SMN telomerique (SMNt). Objective: To report our experience in the molecular analysis of Tunisian SMA patients. Methods: A total of 42 clinically evaluated SMA patients were divided into two groups according to the presence or not of grouped atrophic fibers on muscle biopsy. PCR-RFLP and PCR-SSCP were performed on DNA from all patients in order to detect the SMNt exon 7 deletion. Results: In the first group (grouped atrophic fibres) 24 out of 28 patients showed SMNt exon 7 deletion. In the second group (no grouped atrophic fibres) 12 out of 14 showed non deletion. Conclusion: The presence of grouped atrophic fibres is a helpful finding in the diagnosis of SMA although muscle biopsy is an invasive procedure. We suggest first to screen for the SMNt exon 7 deletion in any clinically suspected SMA patients. Muscle biopsy would be performed only in case where no mutation was detected by molecular study.
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