paramyotonia congenita of von Eulenburg (PMC)

Pathology

• nonprogressive nature
• lack of atrophy or hypertrophy of muscles

Genetics

• autosomal dominant
• associated with defects in SCN4A (Na+ channel alpha subunit)

Clinical manifestations

• myotonia, increased by exposure to cold
• intermittent flaccid paresis, not necessarily dependent on cold or myotonia
• in some patients, myotonia is not increased by cold exposure (paramyotonia without cold paralysis)
• patients may have a combination phenotype of PMC & HYPP

Laboratory

• lability of serum K+

More general terms

• genetic disease of muscle (inherited myopathy)

Additional terms

• familial periodic paralysis (hyperkalemic, normokalemic, hypokalemic, HYPP, NKPP, HYPOPP)

Patient information

paramyotonia congenita patient information

Database

• OMIM: https://mirror.omim.org/entry/168300
• OMIM: https://mirror.omim.org/entry/603967