Nemaline myopathy and distal arthrogryposis associated with an autosomal recessive TNNT3 splice variant.
Hum Mutat
; 39(3): 383-388, 2018 03.
Article
em En
| MEDLINE
| ID: mdl-29266598
ABSTRACT
A male neonate presented with severe weakness, hypotonia, contractures and congenital scoliosis. Skeletal muscle specimens showed marked atrophy and degeneration of fast fibers with striking nemaline rods and hypertrophy of slow fibers that were ultrastructurally normal. A neuromuscular gene panel identified a homozygous essential splice variant in TNNT3 (chr111956150G > A, NM_006757.3c.681+1G > A). TNNT3 encodes skeletal troponin-Tfast and is associated with autosomal dominant distal arthrogryposis. TNNT3 has not previously been associated with nemaline myopathy (NM), a rare congenital myopathy linked to defects in proteins associated with thin filament structure and regulation. cDNA studies confirmed pathogenic consequences of the splice variant, eliciting exon-skipping and intron retention events leading to a frameshift. Western blot showed deficiency of troponin-Tfast protein with secondary loss of troponin-Ifast . We establish a homozygous splice variant in TNNT3 as the likely cause of severe congenital NM with distal arthrogryposis, characterized by specific involvement of Type-2 fibers and deficiency of troponin-Tfast .
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Artrogripose
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Splicing de RNA
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Miopatias da Nemalina
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Troponina T
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Genes Recessivos
Tipo de estudo:
Prognostic_studies
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Risk_factors_studies
Limite:
Humans
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Infant
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Male
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Newborn
Idioma:
En
Revista:
Hum Mutat
Assunto da revista:
GENETICA MEDICA
Ano de publicação:
2018
Tipo de documento:
Article
País de afiliação:
Austrália