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Generalized epilepsy-paroxysmal dyskinesia syndrome(PNKD3)

MedGen UID:
Concept ID:
Disease or Syndrome
Synonyms: Generalized epilepsy and paroxysmal dyskinesia; Paroxysmal nonkinesigenic dyskinesia, 3, with or without generalized epilepsy; PNKD3
Modes of inheritance:
Autosomal dominant inheritance
MedGen UID:
Concept ID:
Intellectual Product
Source: Orphanet
A mode of inheritance that is observed for traits related to a gene encoded on one of the autosomes (i.e., the human chromosomes 1-22) in which a trait manifests in heterozygotes. In the context of medical genetics, an autosomal dominant disorder is caused when a single copy of the mutant allele is present. Males and females are affected equally, and can both transmit the disorder with a risk of 50% for each child of inheriting the mutant allele.
Gene (location): KCNMA1 (10q22.3)
Monarch Initiative: MONDO:0012276
OMIM®: 609446
Orphanet: ORPHA79137


Generalized epilepsy-paroxysmal dyskinesia syndrome is characterised by the association of paroxysmal dyskinesia and generalised epilepsy (usually absence or generalised tonic-clonic seizures) in the same individual or family. The prevalence is unknown. Analysis in one of the reported families led to the identification of a causative mutation in the <i>KCNMA1</i> gene (chromosome 10q22), encoding the alpha subunit of the BK channel. Transmission is autosomal dominant. [from ORDO]

Clinical features

From HPO
MedGen UID:
Concept ID:
Sign or Symptom
A seizure is an intermittent abnormality of nervous system physiology characterized by a transient occurrence of signs and/or symptoms due to abnormal excessive or synchronous neuronal activity in the brain.
Global developmental delay
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Concept ID:
A delay in the achievement of motor or mental milestones in the domains of development of a child, including motor skills, speech and language, cognitive skills, and social and emotional skills. This term should only be used to describe children younger than five years of age.
Paroxysmal dyskinesia
MedGen UID:
Concept ID:
Disease or Syndrome
Episodic bouts of involuntary movements with dystonic, choreic, ballistic movements, or a combination thereof. There is no loss of consciousness during the attacks.
Brisk reflexes
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Concept ID:
Tendon reflexes that are noticeably more active than usual (conventionally denoted 3+ on clinical examination). Brisk reflexes may or may not indicate a neurological lesion. They are distinguished from hyperreflexia by the fact that hyerreflexia is characterized by hyperactive repeating (clonic) reflexes, which are considered to be always abnormal.
EEG with spike-wave complexes (>3.5 Hz)
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Concept ID:
The presence of complexes of spikes and waves (>3.5 Hz) in electroencephalography (EEG).
Generalized non-motor (absence) seizure
MedGen UID:
Concept ID:
Disease or Syndrome
A generalized non-motor (absence) seizure is a type of a type of dialeptic seizure that is of electrographically generalized onset. It is a generalized seizure characterized by an interruption of activities, a blank stare, and usually the person will be unresponsive when spoken to. Any ictal motor phenomena are minor in comparison to these non-motor features.
Bilateral tonic-clonic seizure with generalized onset
MedGen UID:
Concept ID:
Sign or Symptom
A bilateral tonic-clonic seizure with generalized onset is a type of bilateral tonic-clonic seizure characterized by generalized onset; these seizures rapidly engage networks in both hemispheres at the start of the seizure.
MedGen UID:
Concept ID:
Hypotonia is an abnormally low muscle tone (the amount of tension or resistance to movement in a muscle). Even when relaxed, muscles have a continuous and passive partial contraction which provides some resistance to passive stretching. Hypotonia thus manifests as diminished resistance to passive stretching. Hypotonia is not the same as muscle weakness, although the two conditions can co-exist.

Term Hierarchy

CClinical test,  RResearch test,  OOMIM,  GGeneReviews,  VClinVar  
  • CROGVGeneralized epilepsy-paroxysmal dyskinesia syndrome

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