PDF(Pubmed)
Abstract：
UNASSIGNED: Sodium channel myotonia (SCM) belongs to the group of sodium channelopathies with mutations involving SCN4A gene. The main feature of sodium channel myotonia is pure myotonia without episodes of weakness or paralysis. One of the sodium channel myotonia has been classified as acetazolamide-responsive myotonia because of the effectiveness of acetazolamide as an antimyotonic drug.
UNASSIGNED: The child presented with generalized muscle hypertrophy and stiffness involving arms, thighs, calves, chest, and back muscles with unusually prominent trapezius muscle. The parents described the warm-up phenomenon as an improvement in stiffness as the day passes and with repetitive action. Percussion myotonia was illustrated in the thenar eminence and trapezius muscle. Characteristic \'dive-bomber\' sound was present in electromyography, and whole-exome sequencing revealed a novel Ile239Thr mutation in the SCN4A gene. Acetazolamide was prescribed for the condition, and regular follow-up shows an excellent clinical response.
UNASSIGNED: This case presents a pure myotonic phenotype without episodes of weakness or paralysis. Generalized myotonia with muscle hypertrophy and demonstrating warm-up phenomenon resembles myotonia congenita (a chloride channelopathy). However, genetic analysis revealed a novel Ile239Thr mutation involving SCN4A gene indicating this case to be a sodium channelopathy.
UNASSIGNED: This case limelight sodium channel myotonia with a novel Ile239Thr mutation in SCN4A gene that phenotypically resembles myotonia congenita but genetically belongs to sodium channelopathy highlighting the poor correlation between genotypes and phenotypes in non-dystrophic myotonia. Acetazolamide can be a safe and cost-effective antimyotonic drug in sodium channel myotonia.
UNASSIGNED: The child presented with generalized muscle hypertrophy and stiffness involving arms, thighs, calves, chest, and back muscles with unusually prominent trapezius muscle. The parents described the warm-up phenomenon as an improvement in stiffness as the day passes and with repetitive action. Percussion myotonia was illustrated in the thenar eminence and trapezius muscle. Characteristic \'dive-bomber\' sound was present in electromyography, and whole-exome sequencing revealed a novel Ile239Thr mutation in the SCN4A gene. Acetazolamide was prescribed for the condition, and regular follow-up shows an excellent clinical response.
UNASSIGNED: This case presents a pure myotonic phenotype without episodes of weakness or paralysis. Generalized myotonia with muscle hypertrophy and demonstrating warm-up phenomenon resembles myotonia congenita (a chloride channelopathy). However, genetic analysis revealed a novel Ile239Thr mutation involving SCN4A gene indicating this case to be a sodium channelopathy.
UNASSIGNED: This case limelight sodium channel myotonia with a novel Ile239Thr mutation in SCN4A gene that phenotypically resembles myotonia congenita but genetically belongs to sodium channelopathy highlighting the poor correlation between genotypes and phenotypes in non-dystrophic myotonia. Acetazolamide can be a safe and cost-effective antimyotonic drug in sodium channel myotonia.
摘要：
■钠通道肌强直（SCM）属于具有涉及SCN4A基因的突变的钠通道病。钠通道肌强直的主要特征是纯肌强直，没有无力或瘫痪的发作。由于乙酰唑胺作为抗强直性药物的有效性，钠通道肌强直症之一已被归类为乙酰唑胺反应性肌强直症。
■儿童表现为全身肌肉肥大和僵硬，涉及手臂，大腿,小牛,胸部，和背部肌肉异常突出的斜方肌。父母将热身现象描述为随着一天的过去和重复动作，刚度的改善。在大鱼间隆起和斜方肌中说明了打击乐肌强直。肌电图中存在特征性的“俯冲轰炸机”声音，全外显子组测序揭示了SCN4A基因中的一个新的Ile239Thr突变。乙酰唑胺是针对这种情况开的，定期随访显示良好的临床反应。
■此例表现为单纯的肌强直表型，无无力或麻痹发作。伴有肌肉肥大并表现出热身现象的广义肌强直类似于先天性肌强直（氯化物通道病）。然而,遗传分析显示涉及SCN4A基因的新Ile239Thr突变，表明该病例为钠通道病。
■本病例关注钠通道肌强直，在SCN4A基因中出现了一个新的Ile239Thr突变，该突变在表型上类似于先天性肌强直，但在遗传上属于钠通道病，突出了非营养不良性肌强直中基因型和表型之间的相关性差。乙酰唑胺可以是钠通道肌强直的安全且经济有效的抗强直药。
■儿童表现为全身肌肉肥大和僵硬，涉及手臂，大腿,小牛,胸部，和背部肌肉异常突出的斜方肌。父母将热身现象描述为随着一天的过去和重复动作，刚度的改善。在大鱼间隆起和斜方肌中说明了打击乐肌强直。肌电图中存在特征性的“俯冲轰炸机”声音，全外显子组测序揭示了SCN4A基因中的一个新的Ile239Thr突变。乙酰唑胺是针对这种情况开的，定期随访显示良好的临床反应。
■此例表现为单纯的肌强直表型，无无力或麻痹发作。伴有肌肉肥大并表现出热身现象的广义肌强直类似于先天性肌强直（氯化物通道病）。然而,遗传分析显示涉及SCN4A基因的新Ile239Thr突变，表明该病例为钠通道病。
■本病例关注钠通道肌强直，在SCN4A基因中出现了一个新的Ile239Thr突变，该突变在表型上类似于先天性肌强直，但在遗传上属于钠通道病，突出了非营养不良性肌强直中基因型和表型之间的相关性差。乙酰唑胺可以是钠通道肌强直的安全且经济有效的抗强直药。
