National Center for Advancing and Translational Sciences Genetic and Rare Diseases Information Center, a program of the National Center for Advancing and Translational Sciences

Andersen-Tawil syndrome


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:
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
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

This table lists symptoms that people with this disease may have. For most diseases, symptoms will vary from person to person. People with the same disease may not have all the symptoms listed. This information comes from a database called the Human Phenotype Ontology (HPO) . The HPO collects information on symptoms that have been described in medical resources. The HPO is updated regularly. Use the HPO ID to access more in-depth information about a symptom.

Showing of 47 |
Medical Terms Other Names
Learn More:
HPO ID
5%-29% of people have these symptoms
Specific learning disability 0001328
Percent of people who have these symptoms is not available through HPO
Antegonial notching of mandible 0003779
Autosomal dominant inheritance 0000006
Bidirectional ventricular ectopy 0005147
Blepharophimosis
Narrow opening between the eyelids
0000581
Brachydactyly
Short fingers or toes
0001156
Broad forehead
Increased width of the forehead
Wide forehead
[ more ] 		0000337
Bulbous nose 0000414
Cleft palate
Cleft roof of mouth
0000175
Clinodactyly of the 5th finger
Permanent curving of the pinkie finger
0004209
Clinodactyly of the 5th toe 0001864
Delayed eruption of permanent teeth
Delayed eruption of adult teeth
0000696
Delayed skeletal maturation
Delayed bone maturation
Delayed skeletal development
[ more ] 		0002750
Depressivity
Depression
0000716
Facial asymmetry
Asymmetry of face
Crooked face
Unsymmetrical face
[ more ] 		0000324
Growth abnormality
Abnormal growth
Growth issue
[ more ] 		0001507
High palate
Elevated palate
Increased palatal height
[ more ] 		0000218
Hypertelorism
Wide-set eyes
Widely spaced eyes
[ more ] 		0000316
Hypokalemia
Low blood potassium levels
0002900
Hypoplasia of dental enamel
Underdeveloped teeth enamel
0006297
Hypoplasia of the maxilla
Decreased size of maxilla
Decreased size of upper jaw
Maxillary deficiency
Maxillary retrusion
Small maxilla
Small upper jaw
Small upper jaw bones
Upper jaw deficiency
Upper jaw retrusion
[ more ] 		0000327
Joint laxity
Joint instability
Lax joints
Loose-jointedness
Loosejointedness
[ more ] 		0001388
Low-set ears
Low set ears
Lowset ears
[ more ] 		0000369
Malar flattening
Zygomatic flattening
0000272
Microcephaly
Abnormally small skull
Decreased circumference of cranium
Decreased size of skull
Reduced head circumference
Small head circumference
[ more ] 		0000252
Oligodontia
Failure of development of more than six teeth
0000677
Palpitations
Missed heart beat
Skipped heart beat
[ more ] 		0001962
Periodic hypokalemic paresis 0008153
Persistence of primary teeth
Delayed loss of baby teeth
Failure to lose baby teeth
Retained baby teeth
[ more ] 		0006335
Preauricular pit
Pit in front of the ear
0004467
Prolonged QT interval 0001657
Prominent frontal sinuses 0005478
Prominent U wave 0025072
Scapular winging
Winged shoulder blade
0003691
Scoliosis 0002650
Short foot
Short feet
Small feet
[ more ] 		0001773
Short mandibular rami 0003778
Short metacarpal
Shortened long bone of hand
0010049
Short metatarsal
Short long bone of foot
0010743
Short palm 0004279
Short palpebral fissure
Short opening between the eyelids
0012745
Short phalanx of finger
Short finger bones
0009803
Slender long bone
Long bones slender
Thin long bones
[ more ] 		0003100
Small hand
Disproportionately small hands
0200055
Syncope
Fainting spell
0001279
Toe syndactyly
Fused toes
Webbed toes
[ more ] 		0001770
Triangular face
Face with broad temples and narrow chin
Triangular facial shape
[ more ] 		0000325
Showing of 47 |
Last updated: 7/1/2020
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.

If you need medical advice, you can look for doctors or other healthcare professionals who have experience with this disease. You may find these specialists through advocacy organizations, clinical trials, or articles published in medical journals. You may also want to contact a university or tertiary medical center in your area, because these centers tend to see more complex cases and have the latest technology and treatments.

If you can’t find a specialist in your local area, try contacting national or international specialists. They may be able to refer you to someone they know through conferences or research efforts. Some specialists may be willing to consult with you or your local doctors over the phone or by email if you can't travel to them for care.

You can find more tips in our guide, How to Find a Disease Specialist. We also encourage you to explore the rest of this page to find resources that can help you find specialists.

Healthcare Resources

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 related to 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. 

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

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

  • 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.
  • 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

Questions sent to GARD may be posted here if the information could be helpful to others. We remove all identifying information when posting a question to protect your privacy. If you do not want your question posted, please let us know.

  1. Andersen-Tawil syndrome. Genetics Home Reference. April 2006; http://ghr.nlm.nih.gov/condition/andersen-tawil-syndrome. Accessed 8/18/2015.
  2. 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.