Co-occurrence of DMPK expansion and CLCN1 mutation in a patient with myotonia.
CLCN1
DMPK
Myotonia
Myotonia congenita
Myotonic dystrophy type 1
Journal
Neurological sciences : official journal of the Italian Neurological Society and of the Italian Society of Clinical Neurophysiology
ISSN: 1590-3478
Titre abrégé: Neurol Sci
Pays: Italy
ID NLM: 100959175
Informations de publication
Date de publication:
Dec 2021
Dec 2021
Historique:
received:
30
05
2021
accepted:
03
08
2021
pubmed:
14
8
2021
medline:
15
12
2021
entrez:
13
8
2021
Statut:
ppublish
Résumé
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. 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. 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.
Identifiants
pubmed: 34386887
doi: 10.1007/s10072-021-05538-y
pii: 10.1007/s10072-021-05538-y
doi:
Substances chimiques
Chloride Channels
0
DMPK protein, human
0
Myotonin-Protein Kinase
EC 2.7.11.1
Types de publication
Case Reports
Journal Article
Langues
eng
Sous-ensembles de citation
IM
Pagination
5365-5368Informations de copyright
© 2021. Fondazione Società Italiana di Neurologia.
Références
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