Hypokalemic periodic paralysis
Prevalence estimates on Rare Medical Network websites are calculated based on data available from numerous sources, including US and European government statistics, the NIH, Orphanet, and published epidemiologic studies. Rare disease population data is recognized to be highly variable, and based on a wide variety of source data and methodologies, so the prevalence data on this site should be assumed to be estimated and cannot be considered to be absolutely correct.
Age of Onset
Autosomal dominant ?A pathogenic variant in only one gene copy in each cell is sufficient to cause an autosomal dominant disease
Autosomal recessive ?Pathogenic variants in both copies of each gene of the chromosome are needed to cause an autosomal recessive disease and observe the mutant phenotype
X-linked dominant ?X-linked dominant inheritance, sometimes referred to as X-linked dominance, is a mode of genetic inheritance by which a dominant gene is carried on the X chromosome.
X-linked recessive ?Pathogenic variants in both copies of a gene on the X chromosome cause an X-linked recessive disorder
Mitochondrial or multigenic ?Mitochondrial genetic disorders can be caused by changes (mutations) in either the mitochondrial DNA or nuclear DNA that lead to dysfunction of the mitochondria and inadequate production of energy.
Multigenic or multifactor ?Inheritance involving many factors, of which at least one is genetic but none is of overwhelming importance, as in the causation of a disease by multiple genetic and environmental factors.
Other Names (AKA)
Congenital and Genetic Diseases; Nervous System Diseases
Hypokalemic periodic paralysis (HOKPP) is characterized by episodes of muscle paralysis associated with a fall in blood potassium levels (hypokalemia). Episodes typically involve a temporary inability to move muscles in the arms and legs. The first attack usually occurs in childhood or adolescence. Attacks can last for hours or days, and the frequency of attacks varies among people with HOKPP. The frequency is usually highest between the ages of 15 and 35, and then decreases with age. Some people with HOKPP also develop late-onset proximal myopathy.
HOKPP can be caused by
Attacks usually begin in childhood or adolescence, and the frequency of attacks varies. Some people have attacks every day, while others have them once a year. Attacks usually last at least a few hours, to sometimes days. Attacks can occur without warning or they may be triggered by factors such as carbohydrate-rich meals and rest after exercise.
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.
|Medical Terms||Other Names||
|100% of people have these symptoms|
Recurrent low potassium
|Periodic hypokalemic paresis||0008153|
|80%-99% of people have these symptoms|
|Episodic flaccid weakness||0003752|
|Increased intramyocellular lipid droplets||0012240|
|Mildly elevated creatine kinase||0008180|
|30%-79% of people have these symptoms|
|Exercise-induced muscle fatigue||0009020|
|5%-29% of people have these symptoms|
|Late-onset proximal muscle weakness||0003694|
Muscle tissue disease
|1%-4% of people have these symptoms|
|Fatigable weakness of respiratory muscles||0030196|
|Percent of people who have these symptoms is not available through HPO|
Low blood potassium levels
Not all people with a clinical diagnosis of HOKPP are found to have a mutation in one of the genes mentioned above. This suggests that other, yet unidentified genes may also be responsible for the condition.
- a history of episodes of paralysis
- low levels of potassium during attacks, but not between attacks
- the identification of typical "triggers" (i.e., rest after exercise, prolonged immobility)
family historyconsistent with autosomal dominantinheritance. The diagnosis cannot be established by clinical findings alone in the absence of a known family history of the condition.
Of all individuals who meet diagnostic criteria and have
- 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.
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.
- Orphanet Emergency Guidelines is an article which is expert-authored and peer-reviewed that is intended to guide health care professionals in emergency situations involving this condition.
The medication(s) listed below have been approved by the Food and Drug Administration (FDA) as orphan products for treatment of this condition. Learn more orphan products.
- Dichlorphenamide(Brand name: Keveyis) Manufactured by Taro Pharmaceuticals
FDA-approved indication: Treatment of primary hyperkalemic periodic paralysis, primary hypokalemic period paralysis, and related variants
National Library of Medicine Drug Information Portal
Related diseases are conditions that have similar signs and symptoms. A health care provider may consider these conditions in the table below when making a diagnosis. Please note that the table may not include all the possible conditions related to this disease.
Conditions with similar signs and symptoms from Orphanet
The differential diagnosis should include thyrotoxic periodic paralysis (see this term) which is associated with abnormal thyroid hormone levels.
Visit the Orphanet disease page for more information.
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.
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.
- MedlinePlus was designed by the National Library of Medicine to help you research your health questions, and it provides more information about this topic.
- Genetics Home Reference (GHR) contains information on Hypokalemic periodic paralysis. This website is maintained by the National Library of Medicine.
- The National Institute of Neurological Disorders and Stroke (NINDS) collects and disseminates research information related to neurological disorders. Click on the link to view information on this topic.
- 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.
- 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 Hypokalemic periodic paralysis. Click on the link to view a sample search on this topic.
- Bertrand Fontaine. Hypokalemic Periodic Paralysis. Orphanet. June, 2007; https://www.orpha.net/consor/cgi-bin/OC_Exp.php?lng=en&Expert=681.
- Hypokalemic periodic paralysis. Genetics Home Reference. April 2007; https://ghr.nlm.nih.gov/condition=hypokalemicperiodicparalysis.
- Savine Vicart, et al. Hypokalemic Periodic Paralysis. GeneReviews. July 31, 2014; https://www.ncbi.nlm.nih.gov/books/NBK1338/.
- Hypokalemic periodic paralysis. MedlinePlus. October 13, 2015; https://www.nlm.nih.gov/medlineplus/ency/article/000312.htm.
- Laurie Gutmann. Hypokalemic periodic paralysis. UpToDate. Waltham, MA: UpToDate; September, 2016;
- Sripathi N. Periodic Paralyses. Medscape Reference. March 24, 2016; https://emedicine.medscape.com/article/1171678-overview.