Normokalemic periodic paralysis
- Periodic paralysis type 3
- Normokalemic PP
- Potassium-sensitive normokalemic periodic paralysis
The condition causes episodes of extreme muscle weakness that usually begin in infancy or early childhood. These episodes often involve a temporary inability to move muscles in the arms and legs. Factors that may trigger attacks may include rest after exercise; ingesting potassium-rich foods or drinks; stress; fatigue; fasting; and/or exposure to cold temperatures. Muscle strength generally improves between attacks, although many affected people continue to have mild stiffness (myotonia) in some muscles.
The Human Phenotype Ontology provides the following list of signs and symptoms for Normokalemic periodic paralysis. If the information is available, the table below includes how often the symptom is seen in people with this condition. You can use the MedlinePlus Medical Dictionary to look up the definitions for these medical terms.
|Signs and Symptoms||Approximate number of patients (when available)|
|Abnormality of metabolism/homeostasis||-|
|Abnormality of the tongue||-|
|Autosomal dominant inheritance||-|
The Human Phenotype Ontology (HPO) has collected information on how often a sign or symptom occurs in a condition. Much of this information comes from Orphanet, a European rare disease database. The frequency of a sign or symptom is usually listed as a rough estimate of the percentage of patients who have that feature.
The frequency may also be listed as a fraction. The first number of the fraction is how many people had the symptom, and the second number is the total number of people who were examined in one study. For example, a frequency of 25/25 means that in a study of 25 people all patients were found to have that symptom. Because these frequencies are based on a specific study, the fractions may be different if another group of patients are examined.
Sometimes, no information on frequency is available. In these cases, the sign or symptom may be rare or common.
- Hyperkalemic periodic paralysis. Genetics Home Reference. April 2007; http://ghr.nlm.nih.gov/condition/hyperkalemic-periodic-paralysis. Accessed 9/11/2012.
- Karin Jurkat-Rott and Frank Lehmann-Horn. Hyperkalemic Periodic Paralysis Type 1. GeneReviews. May 31, 2011; http://www.ncbi.nlm.nih.gov/books/NBK1496/. Accessed 9/12/2012.
- Michael Rubin. Periodic paralysis. Merck Manuals. January 2008; http://www.merckmanuals.com/home/childrens_health_issues/muscular_dystrophies_and_related_disorders/periodic_paralysis.html#v732922. Accessed 9/12/2012.
- Patrick F. Chinnery, Timothy J. Walls, Michael G. Hanna, David Bates, Peter R. W. Fawcett. Normokalemic periodic paralysis revisited: Does it exist?. Annals of Neurology. August 2002;