AIM： To understand the distinct, clinical features of myotonia congenita in China. METHODS： Case reports of myotonia congenita were retrieved from the Chinese Journal Full-text database, dating between 1980 and 2007...AIM： To understand the distinct, clinical features of myotonia congenita in China. METHODS： Case reports of myotonia congenita were retrieved from the Chinese Journal Full-text database, dating between 1980 and 2007, and analyzed for clinical characteristics of myotonia congenita. RESULTS： There were 35 published reports and 258 cases about myotonia congenita. Six reports （62 cases） were excluded due to lack of clinical data, imprecise diagnosis, or duplication. Finally, 29 published reports and 196 cases （140 males and 56 females） were included in this analysis. About 78.6% of patients were diagnosed with myotonia congenita before the age of 20, and among these, 86.1% were classified as dominant inheritance. Lower and upper extremities were frequently affected with severe symptoms. Eyelids, mouth and lingual muscles, and trunk muscles and cervical muscles were less frequently involved. However, muscles for swallowing, sphincter muscles, and smooth muscles were not involved. There were no reports of cataracts, cardiac conduction block, or dyscrinism. myotonia congenita symptoms were induced or aggravated by cold temperatures in 71.9% of the patients and warming-up effect occurred in 95.6% of the patients. Muscle hypertrophy was observed in 69.6% and percussion of muscles in 76.5% of the patients. Myotonia potential or myotonia-like potential was detected in all patients using electromyography. Muscle fiber swelling or hypertrophy was frequently detected through muscular biopsy. CONCLUSION： Myotonia congenita frequently occurs in males before the age of 20, in particular as the autosomal dominant form of myotonia congenita. Skeletal muscles throughout the body, especially the lower and upper extremities, are involved. However, muscles for swallowing, sphincter muscles, and smooth muscles are not involved. Warming-up effect is the main characteristic of myotonia congenita.展开更多
Paroxysmal kinesigenic dyskinesia（PKD） and myotonia congenita（MC） are independent disorders that share some clinical features. We aimed to investigate the sequences of PRRT2 and CLCN1 in a proband diagnosed with P...Paroxysmal kinesigenic dyskinesia（PKD） and myotonia congenita（MC） are independent disorders that share some clinical features. We aimed to investigate the sequences of PRRT2 and CLCN1 in a proband diagnosed with PKD and suspected MC. Clinical evaluation and auxiliary examinations were performed. Direct sequencing of the entire coding regions of the PRRT2 and CLCN1 genes was conducted. Haplotype analysis confirmed the relationships among the family members. The proband suffered choreoathetosis attacks triggered by sudden movements, and lower-limb weakness a n d s t i ff n e s s t h a t w o r s e n e d i n c o l d w e a t h e r. Carbamazepine monotherapy completely controlled his choreoathetosis and significantly relieved his limb weakness and stiffness. His father, when young, had similar limb stiffness, while his mother and brother were asymptomatic. Genetic analysis revealed that the proband and his father harbored a PRRT2 c.649 dup C mutation, and CLCN1 c.1723C〉T and c.2492A〉G mutations. His brother carried only the two CLCN1 mutations. None of these mutations were identified in his mother and 150 unrelated controls. This is the first report showing the coexistence ofPRRT2 and CLCN1 mutations. Our results also indicate that both the PRRT2 and CLCN1 genes need to be screened if we fail to identify PRRT2 mutations in PKD patients or CLCN1 mutations in MC patients.展开更多
文摘AIM： To understand the distinct, clinical features of myotonia congenita in China. METHODS： Case reports of myotonia congenita were retrieved from the Chinese Journal Full-text database, dating between 1980 and 2007, and analyzed for clinical characteristics of myotonia congenita. RESULTS： There were 35 published reports and 258 cases about myotonia congenita. Six reports （62 cases） were excluded due to lack of clinical data, imprecise diagnosis, or duplication. Finally, 29 published reports and 196 cases （140 males and 56 females） were included in this analysis. About 78.6% of patients were diagnosed with myotonia congenita before the age of 20, and among these, 86.1% were classified as dominant inheritance. Lower and upper extremities were frequently affected with severe symptoms. Eyelids, mouth and lingual muscles, and trunk muscles and cervical muscles were less frequently involved. However, muscles for swallowing, sphincter muscles, and smooth muscles were not involved. There were no reports of cataracts, cardiac conduction block, or dyscrinism. myotonia congenita symptoms were induced or aggravated by cold temperatures in 71.9% of the patients and warming-up effect occurred in 95.6% of the patients. Muscle hypertrophy was observed in 69.6% and percussion of muscles in 76.5% of the patients. Myotonia potential or myotonia-like potential was detected in all patients using electromyography. Muscle fiber swelling or hypertrophy was frequently detected through muscular biopsy. CONCLUSION： Myotonia congenita frequently occurs in males before the age of 20, in particular as the autosomal dominant form of myotonia congenita. Skeletal muscles throughout the body, especially the lower and upper extremities, are involved. However, muscles for swallowing, sphincter muscles, and smooth muscles are not involved. Warming-up effect is the main characteristic of myotonia congenita.
基金supported by grants from the National Natural Science Foundation of China (81330025 and 81125009)
文摘Paroxysmal kinesigenic dyskinesia（PKD） and myotonia congenita（MC） are independent disorders that share some clinical features. We aimed to investigate the sequences of PRRT2 and CLCN1 in a proband diagnosed with PKD and suspected MC. Clinical evaluation and auxiliary examinations were performed. Direct sequencing of the entire coding regions of the PRRT2 and CLCN1 genes was conducted. Haplotype analysis confirmed the relationships among the family members. The proband suffered choreoathetosis attacks triggered by sudden movements, and lower-limb weakness a n d s t i ff n e s s t h a t w o r s e n e d i n c o l d w e a t h e r. Carbamazepine monotherapy completely controlled his choreoathetosis and significantly relieved his limb weakness and stiffness. His father, when young, had similar limb stiffness, while his mother and brother were asymptomatic. Genetic analysis revealed that the proband and his father harbored a PRRT2 c.649 dup C mutation, and CLCN1 c.1723C〉T and c.2492A〉G mutations. His brother carried only the two CLCN1 mutations. None of these mutations were identified in his mother and 150 unrelated controls. This is the first report showing the coexistence ofPRRT2 and CLCN1 mutations. Our results also indicate that both the PRRT2 and CLCN1 genes need to be screened if we fail to identify PRRT2 mutations in PKD patients or CLCN1 mutations in MC patients.
