Novel mutations in the muscle chloride channel CLCN1 gene causing myotonia congenita in Spanish families.
Mutations in the muscular voltage-dependent chloride channel gene (CLCN1), located at 7q35, lead to recessive and dominant myotonia congenita. We report four novel mutations identified in this gene, after clinical, electromyographic, and genetic studies performed on 13 unrelated families. Two of the four mutations (2512insCTCA and A218T) were identified in families with Thomsen's disease, one (Q658X) in a family with Becker's disease, and the fourth (R669C) in a presumably sporadic patient with the Becker phenotype. Although identification of the mutations allows us to establish some genotype/phenotype correlations, this does not wholly account for the clinical heterogeneity and the inheritance patterns of the disease.
de Diego
C
C
Servei de Genètica, Hospital de Sant Pau, Av. Padre Claret 167, Barcelona, 08025, Spain.
Gámez
J
J
Plassart-Schiess
E
E
Lasa
A
A
Del Río
E
E
Cervera
C
C
Baiget
M
M
Gallano
P
P
Fontaine
B
B
D018118:Chloride Channels / Q000235:genetics*; D004576:Electromyography; D006801:Humans; D008297:Male; D018895:Microsatellite Repeats; D008875:Middle Aged; D009124:Muscle Proteins / Q000235:genetics*; D020388:Muscular Dystrophy, Duchenne / Q000235:genetics; D009154:Mutation; D009224:Myotonia Congenita / Q000235:genetics*; D010375:Pedigree; D018807:Polymorphism, Single-Stranded Conformational; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013030:Spain
D018118:Chloride Channels; D009124:Muscle Proteins