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Characteristics of Andersen-Tawil Syndrome
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Purpose
| Condition |
|---|
| Andersen-Tawil Syndrome Andersen Syndrome |
| Study Type: | Observational |
| Study Design: | Observational Model: Cohort Time Perspective: Prospective |
| Official Title: | Andersen-Tawil Syndrome: Genotype-Phenotype Correlation and Longitudinal Study |
- Collect prospective standardized data from participants to help better define the clinical phenotype of ATS. [ Time Frame: 2 years ]
Biospecimen Retention: Samples With DNA
| Enrollment: | 28 |
| Study Start Date: | November 2007 |
| Study Completion Date: | October 2012 |
| Primary Completion Date: | October 2012 (Final data collection date for primary outcome measure) |
ATS is an ion channel disorder that causes episodes of muscle weakness and potentially life-threatening heart arrhythmias for which no treatment has been identified. The majority of ATS cases are caused by a mutation in the KCNJ2 gene; other cases result from unknown causes. The KCNJ2 gene mutation alters potassium channels in such a way that it disrupts the flow of potassium ions in skeletal and heart muscle. This can lead to the characteristic periodic paralysis and irregular heart rhythms. The purpose of this study is to better define the genetic basis, clinical features, and disease progression of ATS. The study will also establish clinically relevant endpoints for use in future clinical studies.
This observational study will last 2 years and will involve three study visits. The first visit will entail a 1.5- to 3.5-day inpatient stay; the length of stay will depend on whether a participant has been taking medications for their symptoms of weakness. Participants will be asked to discontinue use of such medications during the inpatient stay. Participants will not be asked to stop any medications that they may be taking for heart symptoms. This first study visit will include a medical history, a quality of life questionnaire, a physical exam, and muscle strength testing. Nerve, muscle, and heart activity will also be measured, and blood will be drawn for laboratory tests and optional DNA analysis. The second and third study visits will take place 1 and 2 years after the initial study visit and will include the same evaluations. During the 8 weeks following each study visit, participants will record in a telephone diary any muscle and heart symptoms that they experience. During the 1 week after both yearly visits, participants will also undergo an outpatient heart rhythm evaluation. A study coordinator will contact participants once a month by phone over the course of the study to review symptoms.
Eligibility| Ages Eligible for Study: | 10 Years and older (Child, Adult, Senior) |
| Sexes Eligible for Study: | All |
| Accepts Healthy Volunteers: | No |
| Sampling Method: | Non-Probability Sample |
Inclusion Criteria:
-
Clinically confirmed diagnosis of ATS as defined by at least two of the following three criteria:
- Presence of clear-cut episodes of transient muscle weakness with or without a fixed deficit, typically following exertion or prolonged rest OR atypical history with otherwise typical exam findings (absent reflexes with normal sensation during an episode) OR unexplained hypokalemia between episodes OR abnormal long-exercise nerve conduction study
- Heart conduction defects: prolonged QTc interval on 12-lead electrocardiogram OR ventricular ectopy, including uniform or multifocal PVCs, polymorphic VT, or bidirectional VT
- Presence of two or more of the following physical features: low set ears, hypertelorism, small mandible, clinodactyly, syndactyly, micromelia of hands or feet --OR--
- Meets one of the above three criteria and has at least one family member with two of the criteria --OR--
- Does not meet the above three criteria, but possesses a mutation in the KCNJ2 gene
Exclusion Criteria:
- Less than 10 years of age
Contacts and LocationsPlease refer to this study by its ClinicalTrials.gov identifier: NCT00521794
| United States, California | |
| University of California, San Francisco | |
| San Francisco, California, United States, 94143 | |
| United States, Kansas | |
| University of Kansas Medical Center | |
| Kansas City, Kansas, United States, 66160 | |
| United States, New York | |
| University of Rochester School of Medicine and Dentistry | |
| Rochester, New York, United States, 14642 | |
| United States, Texas | |
| University of Texas Southwestern Medical Center | |
| Dallas, Texas, United States, 75390 | |
| Canada, Ontario | |
| London Health Sciences Centre | |
| London, Ontario, Canada, N6A 5A5 | |
| Italy | |
| University of Milan | |
| Milan, Italy | |
| United Kingdom | |
| Institute of Neurology and National Hospital for Neurology | |
| London, United Kingdom | |
| Study Chair: | Emma Ciafaloni, MD | University of Rochester |
| Principal Investigator: | Robert C. Griggs, MD | University of Rochester |
More Information
Publications:
| Responsible Party: | Robert Griggs, MD, Professor of Neurology, Medicine, Pediatrics, Pathology & Laboratory Medicine, and Center for Human Experimental Therapeutics, University of Rochester |
| ClinicalTrials.gov Identifier: | NCT00521794 History of Changes |
| Other Study ID Numbers: |
RDCRN 5301 5U54RR019482-02 ( U.S. NIH Grant/Contract ) |
| Study First Received: | August 24, 2007 |
| Last Updated: | January 15, 2013 |
Keywords provided by Robert Griggs, MD, University of Rochester:
|
Arrhythmia Muscle Weakness Periodic Paralysis Channelopathy |
Additional relevant MeSH terms:
|
Syndrome Andersen Syndrome Disease Pathologic Processes Long QT Syndrome Arrhythmias, Cardiac |
Heart Diseases Cardiovascular Diseases Heart Defects, Congenital Cardiovascular Abnormalities Congenital Abnormalities |
ClinicalTrials.gov processed this record on August 18, 2017