Paramyotonia congenita is autosomal dominant disorder with high penetrance myotonia, increased by exposure to cold intermittent flaccid paresis, not necessarily dependent on cold or myotonia, lability of serum potassium, nonprogressive nature and lack of atrophy or hypertrophy of muscles.
Genes:
SCN4A
Disorders:
Myotonia
Clinical Utility:
Confirmation of a clinical diagnosis, Carrier testing in unaffected family members