Familial hyperkalemic periodic paralysis caused by a de novo mutation in the sodium channel gene SCN4A.
10.3345/kjp.2011.54.11.470
- Author:
Ji Yeon HAN
1
;
June Bum KIM
Author Information
1. Department of Pediatrics, Konyang University College of Medicine, Daejeon, Korea. hoppdoctor@hanmail.net
- Publication Type:Case Report
- Keywords:
Hyperkalemic periodic paralysis;
Mutation;
SCN4A
- MeSH:
Acetazolamide;
Adolescent;
Channelopathies;
Humans;
Hydrochlorothiazide;
Hyperkalemia;
Muscle, Skeletal;
Paralysis;
Paralysis, Hyperkalemic Periodic;
Parents;
Phenotype;
Sodium;
Sodium Channels
- From:Korean Journal of Pediatrics
2011;54(11):470-472
- CountryRepublic of Korea
- Language:English
-
Abstract:
Familial hyperkalemic periodic paralysis (HYPP) is an autosomaldominant channelopathy characterized by transient and recurrent episodes of paralysis with concomitant hyperkalemia. Mutations in the skeletal muscle voltage-gated sodium channel gene SCN4A have been reported to be responsible for this disease. Here, we report the case of a 16-year-old girl with HYPP whose mutational analysis revealed a heterozygous c.2111C>T substitution in the SCN4A gene leading to a Thr704Met mutation in the protein sequence. The parents were clinically unaffected and did not have a mutation in the SCN4A gene. A de novo SCN4A mutation for familial HYPP has not previously been reported. The patient did not respond to acetazolamide, but showed a marked improvement in paralytic symptoms upon treatment with hydrochlorothiazide. The findings in this case indicate that a de novo mutation needs to be considered when an isolated family member is found to have a HYPP phenotype.
