Non-dystrophic myotonia Chilean cohort with predominance of the SCN4A Gly1306Glu variant.
Neuromuscul Disord
; 30(7): 554-561, 2020 07.
Article
em En
| MEDLINE
| ID: mdl-32593548
Non-dystrophic myotonias are a group of rare neuromuscular diseases linked to SCN4A or CLCN1. Among the subtypes, myotonia permanens, associated with the Gly1306Glu variant of SCN4A, is a relatively less frequent but more severe form. Most reports of non-dystrophic myotonias describe European populations. Therefore, to expand the genetic and phenotypic spectrum of this disorder, we evaluated 30 Chilean patients with non-dystrophic myotonias for associated variants and clinical characteristics. SCN4A variants were observed in 28 (93%) of patients, including 25 (83%) with myotonia permanens due to the Gly1306Glu variant. Myotonia permanens was inherited in 24 (96%) patients; the mean age of onset was 6 months, and the initial symptoms were orbicularis oculi myotonia in 17 (74%) patients and larynx myotonia in 12 (52%) patients. The extraocular muscles were involved in 11 (44%) patients, upper limbs in 20 (80%), and lower limbs in 21 (84%). Thirteen (52%) patients experienced recurrent pain and 10 (40%) patients reported limitations in daily life activities. Carbamazepine reduced myotonia in eight treated patients. The high frequency of the Gly1306Glu variant in SCN4A in Chilean patients suggests a founder effect and expands its phenotypic spectrum.
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Canal de Sódio Disparado por Voltagem NAV1.4
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Miotonia
Tipo de estudo:
Etiology_studies
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Incidence_studies
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Observational_studies
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Risk_factors_studies
Limite:
Adolescent
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Adult
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Child
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Female
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Humans
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Infant
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Male
País/Região como assunto:
America do sul
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Chile
Idioma:
En
Revista:
Neuromuscul Disord
Assunto da revista:
NEUROLOGIA
Ano de publicação:
2020
Tipo de documento:
Article
País de publicação:
Reino Unido