| Disease ID | Source | Name | Description |
| 170500 | OMIM | Periodic paralysis hyperkalemic (HYPP) | An autosomal dominant channelopathy characterized by episodic flaccid generalized muscle weakness associated with high levels of serum potassium. Concurrence of myotonia is found in HYPP patients. The disease is caused by variants affecting the gene represented in this entry. |
| 170500 | OMIM | Periodic paralysis hyperkalemic (HYPP) | An autosomal dominant channelopathy characterized by episodic flaccid generalized muscle weakness associated with high levels of serum potassium. Concurrence of myotonia is found in HYPP patients. The disease is caused by variants affecting the gene represented in this entry. |
| 168300 | OMIM | Paramyotonia congenita of von Eulenburg (PMC) | An autosomal dominant channelopathy characterized by myotonia, increased by exposure to cold, intermittent flaccid paresis, not necessarily dependent on cold or myotonia, lability of serum potassium, non-progressive nature and lack of atrophy or hypertrophy of muscles. In some patients, myotonia is not increased by cold exposure (paramyotonia without cold paralysis). Patients may have a combination phenotype of PMC and HYPP. The disease is caused by variants affecting the gene represented in this entry. |
| 613345 | OMIM | Periodic paralysis hypokalemic 2 (HOKPP2) | An autosomal dominant disorder manifested by episodic flaccid generalized muscle weakness associated with falls of serum potassium levels. The disease is caused by variants affecting the gene represented in this entry. |
| 614198 | OMIM | Myasthenic syndrome, congenital, 16 (CMS16) | A form of congenital myasthenic syndrome, a group of disorders characterized by failure of neuromuscular transmission, including pre-synaptic, synaptic, and post-synaptic disorders that are not of autoimmune origin. Clinical features are easy fatigability and muscle weakness. CMS16 is characterized by fatigable generalized weakness and recurrent attacks of respiratory and bulbar paralysis since birth. The fatigable weakness involves lid-elevator, external ocular, facial, limb and truncal muscles and an decremental response of the compound muscle action potential on repetitive stimulation. The disease is caused by variants affecting the gene represented in this entry. |
| 608390 | OMIM | Myotonia SCN4A-related (MYOSCN4A) | A phenotypically highly variable myotonia aggravated by potassium loading, and sometimes by cold. Myotonia is characterized by sustained muscle tensing that prevents muscles from relaxing normally. It causes muscle stiffness that can interfere with movement. In some people the stiffness is very mild, while in other cases it may be severe enough to interfere with walking, running, and other activities of daily life. Myotonia SCN4A-related includes myotonia permanens and myotonia fluctuans. In myotonia permanens, the myotonia is generalized and there is a hypertrophy of the muscle, particularly in the neck and the shoulder. Attacks of severe muscle stiffness of the thoracic muscles may be life threatening due to impaired ventilation. In myotonia fluctuans, the muscle stiffness may fluctuate from day to day, provoked by exercise. The disease is caused by variants affecting the gene represented in this entry. |