Familial paroxysmal nonkinesigenic dyskinesia is a disorder of the nervous system that causes episodes of involuntary movement. Paroxysmal indicates that the abnormal movements come and go over time. Nonkinesigenic means that episodes are not triggered by sudden movement. Dyskinesia broadly refers to involuntary movement of the body.

Mutations in the PNKD gene can cause familial paroxysmal nonkinesigenic dyskinesia. The function of the protein produced from the PNKD gene is unknown, although it is thought to play an important role in normal brain function. The PNKD protein may help control the release of chemicals in the brain called neurotransmitters, which allow nerve cells (neurons) to communicate with each other.

Familial paroxysmal nonkinesigenic dyskinesia is a very rare disorder. Its prevalence is estimated to be 1 in 5 million people.

This condition is inherited in an autosomal dominant pattern, which means one copy of the altered gene in each cell is typically sufficient to cause the disorder. In all reported cases caused by PNKD gene mutations, an affected person has inherited the mutation from one parent. A small number of people with the altered gene have not developed signs and symptoms of the condition, a situation known as reduced penetrance.

Published Date: August 01, 2017
Published By: National Institutes of Health