Inherited Myokymia: A Clinical and Genetic Study of a Family

• Conditions: A Study of Clinical and Genetic Mutations in a Family of Neuromyotonia, so Called Isaac's Syndrome

• Registration Number: NCT01250704
• Lead Sponsor: China Medical University Hospital

Brief Summary

Neuromyotonia (NMT), so called Isaac's syndrome, is a rare disorder in which hyperexcitability of peripheral motor nerves leads to intermittent muscle contractions. It is characterized by muscle twitching at rest (visible myokymia), cramps, hyperhidrosis, paraesthesiae, mild muscle weakness. and impaired muscle relaxation, or pseudomyotonia. Electromyographic recording is a key diagnostic tool in detecting myokymia and neuromyotonia. Pathophysiology of neuromyotonia is claimed to be related immune disorder, autoimmune anti-voltage-gated potassium-channel antibodies and genetic mutation in potassium channel. KCNA1 (Kv1.1) mutation was mostly reported in a autosomal dominant trait. In the present study, we report a family affected with myokymia，worsening with elevated body temperature, febrile illness or spicy food. How the change in temperature influence clinical features of channelopathies is an interesting topic. Variant clinical severity of family members are recorded. The index patient has possible autoimmune mechanism involvement because of his clinical feature of myasthenia gravis with thymoma and hyperthyroidism. Further analyzing the genetic mutation in potassium channelopathy may provide researchers some pathophysiological insight into the Isaac's syndrome.

Detailed Description

Not available

Study Timeline

• Study Start: 2010-04
• Status Verified: 2010-11
• Study First Submitted: 2010-11-29
• Study First Submitted QC: 2010-11-29
• Last Update Submitted: 2010-11-29
• Study First Posted: 2010-12-01
• Last Update Posted: 2010-12-01
• Primary Completion: 2011-03

Recruitment & Eligibility

• Status: UNKNOWN
• Sex: All
• Target Recruitment: 18

Inclusion Criteria

• The disease was initially diagnosed of Isaacs syndrome by two neurologist(Dr Tsai and Dr Yang). We will recruit family members of diseased patient and normal subjects for clinical, electromyographic and genetic studies.

Exclusion Criteria

• none

Study & Design

• Study Type: OBSERVATIONAL
• Study Design: Not specified

Trial Locations

Locations (2)

China medical university hospital; 🇨🇳 Taichung, Taiwan

China Medical University Hospital; 🇨🇳 Taichung, Taiwan