Paramyotonia congenita and hyperkalemic periodic paralysis associated with a Met 1592 Val substitution in the skeletal muscle sodium channel α subunit — a large kindred with a novel phenotype

  title={Paramyotonia congenita and hyperkalemic periodic paralysis associated with a Met 1592 Val substitution in the skeletal muscle sodium channel $\alpha$ subunit — a large kindred with a novel phenotype},
  author={Peter Kelly and W. S. Yang and Donal A. Costigan and M. A. Farrell and Susan Murphy and Orla Hardiman},
  journal={Neuromuscular Disorders},

Severe infantile hyperkalaemic periodic paralysis and paramyotonia congenita: broadening the clinical spectrum associated with the T704M mutation in SCN4A

Evidence that this mutation at codon 704 (T704M) in exon 13 of the skeletal muscle voltage gated sodium channel gene (SCN4A) is a common cause of hyperPP/PMC is supported.

Paralysis periodica paramyotonica caused by SCN4A Arg1448Cys mutation.

[Normokalemic periodic paralysis lasting for two weeks: a severe form of sodium channelopathy with M1592V mutation].

It is indicated that M1592V mutation shares a much greater clinical diversity ranging from congenital paramyotonia to periodic paralysis with a longer duration as well as longer paralytic episodes compared to classical hyperkalemic/normokalemic periodic paralysis.

Lack of sodium channel mutation in an Italian family with paramyotonia congenita.

The existence of a second gene different from SCN4A that can give rise to a clinical PC phenotype can be speculated upon.

Paramyotonia Congenita with Persistent Distal and Facial Muscle Weakness: A Case Report with Literature Review.

PC associated with the T1313M mutation is a possible cause of persistent distal hand weakness and Phenotypic variation within the family was remarkable, as the two younger affected patients did not present with persistent weakness or muscle atrophy.

Overlap of periodic paralysis and paramyotonia congenita caused by SCN4A gene mutations two family reports and literature review

SCN4A gene mutations can cause the overlap of PMC and PP (especially the HypoPP2), and the clinical symptoms of episodic weakness and stiffness could happen at a different time or temperature.

New mutations of SCN4A cause a potassium-sensitive normokalemic periodic paralysis

A potassium-sensitive and normokalemic type of periodic paralysis caused by new SCN4A mutations at codon 675 is reported.

An unusual pathologic feature and phenotype associated with familial hyperkalemic periodic paralysis

A patient with an atypical HyperPP phenotype and a muscle biopsy showing mononuclear cell infiltration in the endomysium is described, which shows evidence of an inflammatory myopathy as well as usual hyperkalemic myopathic changes.

Periodic paralysis.



Sodium channel mutations in paramyotonia congenita and hyperkalemic periodic paralysis

Five other HYPP and PC families have been ascertained, and previously reported sodium channel mutations have been identified in each, and an additional mutation is reported, a leucine ‐ arginine substirution in the ss segment of domain 4 (L1433R), that results in the PC phenotype.

Paramyotonia congenita and hyperkalemic periodic paralysis map to the same sodium-channel gene locus.

Linkage results implicate a sodium-channel gene as an important candidate for the site of mutation responsible for PC, and provide strong evidence for the hypothesis that PC and HYPP are allelic disorders.

Hyperkalemic periodic paralysis

A novel procedure is described, using ligase chain reaction (LCR), to simultaneously identify two different point mutations and one rare, apparently benign polymorphism that results in a nonconservative amino acid substitution in hyperkalemic periodic paralysis.

Hyperkalemic periodic paralysis and the adult muscle sodium channel alpha-subunit gene.

Parts of the adult muscle sodium channel alpha-subunit gene were cloned and mapped near the human growth hormone locus (GH1) on chromosome 17 and showed tight linkage to the genetic defect with no recombinants detected.

Novel mutations in families with unusual and variable disorders of the skeletal muscle sodium channel

Two mutations in SCN4A which affect regions of the sodium channel not previously associated with a disease phenotype are found, causing affected family members to display an unusual mixture of clinical features reminiscent of PMC, HPP and of a third disorder, myotonia congenita (MC).

Hyperkalemic periodic paralysis with cardiac dysrhythmia: A novel sodium channel mutation?

A patient is presented with hyperkalemic periodic paralysis (HyperPP) and a cardiac dysrhythmia. An amino acid substitution (Val783Ile) in the adult skeletal muscle sodium channel gene was detected.

Paramyotonia congenita or hyperkalemic periodic paralysis? Clinical and electrophysiological features of each entity in one family

It is suggested that PC and HPP represent part of the spectrum of a single genetic disorder and evoked response testing, with exercise and cold provocation, may be useful in determining the physiologic pattern that predominates in any one individual.

A Met-to-Val mutation in the skeletal muscle Na+ channel α-subunit in hyperkalaemic periodic paralysis

An A - G substitution in the patient's messenger RNA that causes a Met-Val change in a highly conserved region of the α-subunit, predicted to be in a transmembrane domain is identified and discovered a voltage-gated channel mutation responsible for a human genetic disease.