Co-occurrence of DMPK expansion and CLCN1 mutation in a patient with myotonia.
Neurol Sci
; 42(12): 5365-5368, 2021 Dec.
Article
em En
| MEDLINE
| ID: mdl-34386887
ABSTRACT
INTRODUCTION:
Myotonic disorders are a group of diseases affecting the muscle, in different ways. Myotonic dystrophy type 1 (DM1) is related to (CTG)n expansion in the 3-untranslated region of the dystrophia myotonica protein kinase (DMPK) gene and is the most frequent and disabling form, causing muscular, visibility, respiratory, and cardiac impairment. Non-dystrophic myotonias (NDMs) affect the skeletal muscle alone. In particular, mutations in the chloride channel (CLCN1) gene cause myotonia congenita (MC), which can have autosomal dominant or recessive inheritance. CASE REPORT We describe a patient with a family history of asymptomatic or paucisymptomatic myotonia, who presented handgrip myotonia which sharply reduced after mexiletine administration. Molecular analysis showed both a paternally inherited DMPK expansion and a maternally inherited CLCN1 mutation.CONCLUSIONS:
Only one other similar case was reported so far; however, the segregation of the two mutations and the characteristics of the muscle were not studied. Since our patient lacked the classical phenotypical and muscle histopathological characteristics of DM1 and showed mild splicing alterations despite a pathogenic DMPK expansion and the nuclear accumulation of toxic RNA, we may speculate that the co-occurrence of a CLCN1 mutation could have attenuated the severity of DM1 phenotype.Palavras-chave
Texto completo:
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Bases de dados:
MEDLINE
Assunto principal:
Miotonia
/
Distrofia Miotônica
/
Miotonia Congênita
Limite:
Humans
Idioma:
En
Revista:
Neurol Sci
Assunto da revista:
NEUROLOGIA
Ano de publicação:
2021
Tipo de documento:
Article
País de afiliação:
Itália