The p.A1156T mutation alters the function of the voltage-gated sodium channel Nav1.4 on the muscle sarcolemma, causing a channelopathy without overt myotonia or periodic paralysis but with myalgic pain.
The present study is to observe in vitro the proliferation ability of the muscle cells from permanent myopathy (PM) patients of nomokalaemic periodic paralysis (normKPP), which is caused by mutations of Met1592Val in the skeletal muscle voltage gated sodium channel (SCN4A) gene on chromosome 17q23.1.
[The construction and preliminary investigation of the cell model of a novel mutation R675Q in the SCN4A gene identified in a Chinese family with normokalemic periodic paralysis].
Like the cardiac disorders (long QT syndrome type 3 or Brugada syndrome) and generalized epilepsy with febrile seizures plus (GEFS+) associated with C-terminal mutations in other NaV channels, the primary effect of F1705I was a partial disruption of fast inactivation.
[The construction and preliminary investigation of the cell model of a novel mutation R675Q in the SCN4A gene identified in a Chinese family with normokalemic periodic paralysis].
Like the cardiac disorders (long QT syndrome type 3 or Brugada syndrome) and generalized epilepsy with febrile seizures plus (GEFS+) associated with C-terminal mutations in other NaV channels, the primary effect of F1705I was a partial disruption of fast inactivation.
These results, showing that the I1495F and T704Mhyperkalaemic periodic paralysis mutations both have profound effects on channel activation and fast-slow inactivation, suggest that the S5 segment maybe in a location where fast and slow inactivation converge.