Genetic Mutations and Demographic, Clinical, and Morphological Aspects of Myofibrillar Myopathy in a French Cohort.
Genet Test Mol Biomarkers
; 22(6): 374-383, 2018 Jun.
Article
em En
| MEDLINE
| ID: mdl-29924655
ABSTRACT
BACKGROUND:
Protein aggregate myopathies (PAM) represent a group of familial or sporadic neuromuscular conditions with marked clinical and genetic heterogeneity that occur in children and adults. Familial PAM includes myofibrillar myopathies defined by the presence of desmin-positive protein aggregates and degenerative intermyofibrillar network changes. PAM is often caused by dysfunctional genes, such as DES, PLEC 1, CRYAB, FLNC, MYOT, ZASP, BAG3, FHL1, and DNAJB6.OBJECTIVE:
To retrospectively analyze genetic mutations and demographic, clinical, and morphological aspects of PAM in a French population.METHODS:
Forty-eight PAM patients (29 men, 19 women) were divided into two groups, those with genetically (GIM) and nongenetically identified (NGIM) mutations associated with myofibrillar myopathy.RESULTS:
Age of myopathy onset ranged from 13 to 68 years. GIM group mutations (81.25%) included DES (14), ZASP (8), FLNC (4), MYOT (4), BAG3 (1), CRYAB (2), and DNAJB6 (6). The MYOT subgroup displayed a significantly older onset age (p = 0.029). Autosomal dominant inheritance was found in 74.3% of GIM and 44.4% of NGIM subjects. Overall, 22.9% had Maghrebian heritage, 72.9% Caucasian, and 4.2% Asian. The most common clinical sign was distal muscle weakness (66%) followed by simultaneous distal and proximal weakness in 49%. Eleven patients had contractures, one had a rigid spine, and five had respiratory dysfunction. GIM subjects had greater cardiac involvement (51.7%) versus the NGIM group (33.3%). The average serum creatine kinase level was 393 U/L in GIM and 382 U/L in NGIM subjects. Morphological analysis showed significant differences among GIM subgroups, including the number of vacuoles and regenerated fibers (ZASP), group atrophy (ZASP), and rubbed out fibers (MYOT). Ultrastructural findings showed significant differences in intranuclear rods, Z-disc thickness, and intranuclear inclusions between gene mutation subgroups. Paracrystalline inclusions were present in three patients (DNAJB6). The most frequent mutation in was in DES, followed by ZASP.CONCLUSIONS:
GIM and NGIM PAM subjects showed similar results, suggesting that any unknown genes, which cause this disease have characteristics similar to those already described. Considering the complexity of clinical, morphological, and genetic data related to PAM, particularly myofibrillar myopathies, physicians should be careful when diagnosing patients with sporadic PAM.Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Miopatias Congênitas Estruturais
/
Mutação
Tipo de estudo:
Etiology_studies
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Incidence_studies
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Observational_studies
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Prognostic_studies
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Risk_factors_studies
Limite:
Adolescent
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Adult
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Aged
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Female
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Humans
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Male
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Middle aged
País/Região como assunto:
Europa
Idioma:
En
Revista:
Genet Test Mol Biomarkers
Assunto da revista:
BIOLOGIA MOLECULAR
/
GENETICA
Ano de publicação:
2018
Tipo de documento:
Article
País de afiliação:
Brasil