Effect of Potassium and Acetazolamide on People With Andersen-Tawil Syndrome

• Status: Terminated
• Trial end date: 2011-01-01
• Target enrollment: 0
• Participant gender: All

Summary

Andersen-Tawil Syndrome (ATS) is a rare genetic disorder that causes episodes of muscle weakness, potentially life-threatening changes in heart rhythm, and skeletal developmental abnormalities. The cause of some ATS cases remains unknown, and no specific treatments have been established. The purpose of this study is to determine whether potassium supplements and/or the medication acetazolamide affect the duration of muscle weakness and heart rhythm abnormalities in people with ATS.

• Phase: Phase 1
• Accepts Healthy Volunteers?: No

Details

• Lead Sponsor: University of Rochester
• Collaborators: National Institute of Neurological Disorders and Stroke (NINDS); Office of Rare Diseases (ORD); Rare Diseases Clinical Research Network
• Treatments: Acetazolamide

Criteria

Inclusion Criteria:

• Clinically confirmed diagnosis of Andersen-Tawil Syndrome, as defined by at least two of the following three features:

1. Neuromuscular Feature

• Presence of clear-cut episodes of transient muscle weakness with or without a fixed deficit that is typical with rest after exertion or prolonged rest, OR

• An atypical history with specific exam findings (absent reflexes with normal sensation ictally), OR

• Unexplained intraictal hypokalemia, OR

• An abnormal nerve conduction exercise test

2. Cardiac Feature

• Prolonged QTc interval on 12-lead electrocardiogram (ECG), according to standard criteria, AND/OR

• Ventricular ectopy, including uniform or multifocal PVCs, polymorphic VT, or bidirectional VT

3. Physical Feature (at least two of the below five features)

• Low set ears

• Hypertelorism

• Small mandible

• Clinodactyly

• Syndactyly

• Micromelia of hands or feet

-OR-

• One of the three above criteria, with at leat one other family member meeting two criteria

-OR-

• Not meeting clinical criteria but possessing the KCNJ2 mutation

• An average frequency of at least one neuromuscular symptom (attack of weakness) per week

Exclusion Criteria:

• Sulfa allergy

• Renal impairment, as defined by serum creatine greater than 1.5 mg/dl

• History of renal calculi

• Cardiac disease or other disease that would make potassium supplementation or acetazolamide treatment inadvisable

• Diabetes mellitus

• Currently taking quinidine

• Pregnant