Andersen-Tawil syndrome

Title

Other Names:

Long QT syndrome 7; LQT7; Potassium-sensitive periodic paralysis, ventricular ectopy, and dysmorphic features; Long QT syndrome 7; LQT7; Potassium-sensitive periodic paralysis, ventricular ectopy, and dysmorphic features; Andersen cardiodysrhythmic periodic paralysis; Periodic paralysis, potassium-sensitive cardiodysrhythmic type See More

Categories:

Congenital and Genetic Diseases; Heart Diseases; Nervous System Diseases; Congenital and Genetic Diseases; Heart Diseases; Nervous System Diseases; RDCRN See More

Summary Summary

Andersen-Tawil syndrome is a type of long QT syndrome and is also considered a rare form of periodic paralysis. It causes episodes of muscle weakness, changes in heart rhythm (arrhythmia), and developmental abnormalities. Physical abnormalities associated with this condition typically affect the head, face, and limbs. About 60% of cases of Andersen-Tawil syndrome are caused by mutations in the KCNJ2 gene. The cause of the remaining cases remains unknown. This condition is inherited in an autosomal dominant pattern.^[1]^[2]

Last updated: 8/18/2015

Symptoms Symptoms

Anderson-Tawil syndrome causes episodes of muscle weakness (periodic paralysis), changes in heart rhythm (arrhythmia), and developmental abnormalities. The most common changes affecting the heart are ventricular arrhythmia, which is a disruption in the rhythm of the heart's lower chambers, and long QT syndrome. Long QT syndrome is a heart condition that causes the heart muscle to take longer than usual to recharge between beats. If untreated, the irregular heartbeats can lead to discomfort, fainting, or cardiac arrest.^[1]

Physical abnormalities associated with Andersen-Tawil syndrome typically affect the head, face, and limbs. These features often include a very small lower jaw (micrognathia), dental abnormalities, low-set ears, widely spaced eyes, and unusual curving of the fingers or toes (clinodactyly). Some affected people also have short stature and an abnormal curvature of the spine (scoliosis).^[1]

Last updated: 8/18/2015

The Human Phenotype Ontology (HPO) provides the following list of features that have been reported in people with this condition. Much of the information in the HPO comes from Orphanet, a European rare disease database. If available, the list includes a rough estimate of how common a feature is (its frequency). Frequencies are based on a specific study and may not be representative of all studies. You can use the MedlinePlus Medical Dictionary for definitions of the terms below.

Signs and Symptoms	Approximate number of patients (when available)
Specific learning disability	Occasional (present in 5%-29% of cases)
Antegonial notching of mandible	-
Autosomal dominant inheritance	-
Bidirectional ventricular ectopy	-
Blepharophimosis	-
Brachydactyly	-
Broad forehead	-
Bulbous nose	-
Clinodactyly of the 5th finger	-
Clinodactyly of the 5th toe	-
Delayed eruption of permanent teeth	-
Delayed skeletal maturation	-
Depression	-
Facial asymmetry	-
Growth abnormality	-
High palate	-
Hypertelorism	-
Hypoplasia of dental enamel	-
Hypoplasia of the maxilla	-
Joint laxity	-
Low-set ears	-
Malar flattening	-
Microcephaly	-
Oligodontia	-
Palpitations	-
Periodic hypokalemic paresis	-
Persistence of primary teeth	-
Preauricular pit	-
Prolonged QT interval	-
Prominent frontal sinuses	-
Scapular winging	-
Scoliosis	-
Short foot	-
Short mandibular rami	-
Short metacarpal	-
Short metatarsal	-
Short palm	-
Short palpebral fissure	-
Short phalanx of finger	-
Slender long bone	-
Small hand	-
Syncope	-
Toe syndactyly	-
Triangular face	-

Last updated: 9/1/2017

Diagnosis Diagnosis

Yes, the Genetic Testing Registry (GTR) provides information about the genetic tests for this condition. The intended audience for the GTR is health care providers and researchers. Patients and consumers with specific questions about a genetic test should contact a health care provider or a genetics professional.

Last updated: 8/18/2015

The diagnosis of Andersen-Tawil syndrome might be suspected in individuals with either:^[2]

1. Two of the following three criteria:

Periodic paralysis
Symptomatic cardiac arrhythmias or evidence of enlarged U-waves, ventricular ectopy, or a prolonged QTc or QUc interval on electrocardiogram (ECG)
Characteristic facial features, dental abnormalities, small hands and feet, and at least two of the following:
- Low-set ears
- Widely spaced eyes
- Small lower jaw (mandible)
- Fifth-digit clinodactyly (curved pinky finger)
- Syndactyly
  
  or

2. One of the above three criteria in addition to at least one other family member who meets two of the three criteria.

The presence of a mutation in the KCNJ2 gene confirms the diagnosis of Andersen-Tawil syndrome.^[2]

Last updated: 8/18/2015

Testing Resources

The Genetic Testing Registry (GTR) provides information about the genetic tests for this condition. The intended audience for the GTR is health care providers and researchers. Patients and consumers with specific questions about a genetic test should contact a health care provider or a genetics professional.
Orphanet lists international laboratories offering diagnostic testing for this condition.

Treatment Treatment

The resources below provide information about treatment options for this condition. If you have questions about which treatment is right for you, talk to your healthcare professional.

Management Guidelines

GeneReviews provides current, expert-authored, peer-reviewed, full-text articles describing the application of genetic testing to the diagnosis, management, and genetic counseling of patients with specific inherited conditions.

Do you have updated information on this condition? Let us know.

Research Research

Research helps us better understand diseases and can lead to advances in diagnosis and treatment. This section provides resources to help you learn about medical research and ways to get involved.

Clinical Research Resources

ClinicalTrials.gov lists trials that are studying or have studied Andersen-Tawil syndrome. Click on the link to go to ClinicalTrials.gov to read descriptions of these studies.

Please note: Studies listed on the ClinicalTrials.gov website are listed for informational purposes only; being listed does not reflect an endorsement by GARD or the NIH. We strongly recommend that you talk with a trusted healthcare provider before choosing to participate in any clinical study.
Orphanet lists European clinical trials, research studies, and patient registries enrolling people with this condition.

Organizations Organizations

Support and advocacy groups can help you connect with other patients and families, and they can provide valuable services. Many develop patient-centered information and are the driving force behind research for better treatments and possible cures. They can direct you to research, resources, and services. Many organizations also have experts who serve as medical advisors or provide lists of doctors/clinics. Visit the group’s website or contact them to learn about the services they offer. Inclusion on this list is not an endorsement by GARD.

Organizations Supporting this Disease

Muscular Dystrophy UK
61A Great Suffolk Street
London, SE1 0BU United Kingdom
Toll-free: 0800 652 6352 (Helpline)
Telephone: (+44) 0 020 7803 4800
E-mail: info@musculardystrophyuk.org
Website: http://www.musculardystrophyuk.org/
Periodic Paralysis Association
155 West 68th Street
Apartment 1732
New York, NY 10023
Telephone: 407-339-9499
E-mail: lfeld@cfl.rr.com
Website: http://www.periodicparalysis.org
Periodic Paralysis International
2235 B 36th St. SW
Calgary, Alberta, T3E 2Z3 Canada
Telephone: +1-403-244-7213
E-mail: http://hkpp.org/contact
Website: http://www.hkpp.org
Sudden Arrhythmia Death Syndromes Foundation
4527 S 2300 E, Suite 104
Salt Lake City, UT 84117-4448
Telephone: 801-272-3022
Website: http://www.sads.org

Do you know of an organization? Send us your suggestions.

Living With Living With

Living with a genetic or rare disease can impact the daily lives of patients and families. These resources can help families navigate various aspects of living with a rare disease.

Genetics Resources

To find a medical professional who specializes in genetics, you can ask your doctor for a referral or you can search for one yourself. Online directories are provided by GeneTests, the American College of Medical Genetics, and the National Society of Genetic Counselors. If you need additional help, contact a GARD Information Specialist. You can also learn more about genetic consultations from Genetics Home Reference.

Learn More Learn More

These resources provide more information about this condition or associated symptoms. The in-depth resources contain medical and scientific language that may be hard to understand. You may want to review these resources with a medical professional.

Where to Start

Genetics Home Reference (GHR) contains information on Andersen-Tawil syndrome. This website is maintained by the National Library of Medicine.
The National Heart, Lung, and Blood Institute (NHLBI) has information on this topic. NHLBI is part of the National Institutes of Health and supports research, training, and education for the prevention and treatment of heart, lung, and blood diseases.

In-Depth Information

Medscape Reference provides information on this topic. You may need to register to view the medical textbook, but registration is free.
MeSH® (Medical Subject Headings) is a terminology tool used by the National Library of Medicine. Click on the link to view information on this topic.
The Monarch Initiative brings together data about this condition from humans and other species to help physicians and biomedical researchers. Monarch’s tools are designed to make it easier to compare the signs and symptoms (phenotypes) of different diseases and discover common features. This initiative is a collaboration between several academic institutions across the world and is funded by the National Institutes of Health. Visit the website to explore the biology of this condition.
Online Mendelian Inheritance in Man (OMIM) is a catalog of human genes and genetic disorders. Each entry has a summary of related medical articles. It is meant for health care professionals and researchers. OMIM is maintained by Johns Hopkins University School of Medicine.
Orphanet is a European reference portal for information on rare diseases and orphan drugs. Access to this database is free of charge.
PubMed is a searchable database of medical literature and lists journal articles that discuss Andersen-Tawil syndrome. Click on the link to view a sample search on this topic.

Videos/Presentations

Identification and Treatment of Sudden Death Conditions in Young Patients. A presentation by David Bradley, M.D., Director, Pediatric Heart Rhythm Service, CS Mott Children's Hospital. Assoicate Professor, Department of Pediatrics and Communicable Diseases, University of Michigan.

News & Events News & Events

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References References

Andersen-Tawil syndrome. Genetics Home Reference. April 2006; http://ghr.nlm.nih.gov/condition/andersen-tawil-syndrome. Accessed 8/18/2015.
Statland JM, Tawil R, Venance SL. Andersen-Tawil Syndrome. GeneReviews. August 6, 2015; http://www.ncbi.nlm.nih.gov/books/NBK1264/. Accessed 8/18/2015.

Do you know of a review article? Send us your suggestions.