Traits

Traits linked to SCN1B

sodium voltage-gated channel beta subunit 1

The Human Phenotype Ontology links 142 traits to SCN1B, by body system: features seen in people with one of the gene's rare conditions.

SCN1B

Abnormality of the nervous system

Trait	How often it is seen
Epilepsy	Always
Generalized myoclonic seizure	Always
Grand mal seizures	Always
Epileptic encephalopathy	Very often (80–99%)
Focal motor seizure	Very often (80–99%)
Generalized-onset seizure	Very often (80–99%)
Global developmental delay	Very often (80–99%)
Intellectual disability	Very often (80–99%)
Loss of developmental milestones	Very often (80–99%)
Progressive gait ataxia	Very often (80–99%)
Seizure affecting one half of brain	Very often (80–99%)
Anxiety	Often (30–79%)
Atypical absence seizure	Often (30–79%)
Autism spectrum disorder	Often (30–79%)
Brief seizures with staring spells	Often (30–79%)
Cognitive impairment	Often (30–79%)
Complex febrile seizure	Often (30–79%)
Difficulty sleeping	Often (30–79%)
EEG abnormality	Often (30–79%)
EEG with burst suppression	Often (30–79%)
Epilepsia partialis continua	Often (30–79%)
Febrile seizure (within the age range of 3 months to 6 years)	Often (30–79%)
Focal aware seizure	Often (30–79%)
Focal hemiclonic seizure	Often (30–79%)
Focal impaired awareness seizure	Often (30–79%)
Focal tonic seizure	Often (30–79%)
Generalized clonic seizure	Often (30–79%)
Hypsarrhythmia	Often (30–79%)
Increased reflexes	Often (30–79%)
Interictal epileptiform activity	Often (30–79%)
Jerking	Often (30–79%)
Lethargy	Often (30–79%)
Multifocal epileptiform discharges	Often (30–79%)
Obsessive-compulsive trait	Often (30–79%)
Parkinsonism	Often (30–79%)
Photosensitive myoclonic seizure	Often (30–79%)
Photosensitive tonic-clonic seizure	Often (30–79%)
Slow movements	Often (30–79%)
Action tremor	Sometimes (5–29%)
Ataxia	Sometimes (5–29%)
Atypical absence status epilepticus	Sometimes (5–29%)
Choreoathetosis	Sometimes (5–29%)
Cortical dysplasia	Sometimes (5–29%)
Degeneration of cerebellum	Sometimes (5–29%)
Delayed myelination	Sometimes (5–29%)
Diffuse cerebral atrophy	Sometimes (5–29%)
Diffuse white matter abnormalities	Sometimes (5–29%)
Disorder of involuntary muscle movements	Sometimes (5–29%)
Dysgenesis of the hippocampus	Sometimes (5–29%)
EEG with focal epileptiform discharges	Sometimes (5–29%)
EEG with generalized epileptiform discharges	Sometimes (5–29%)
EEG with spike-wave complexes	Sometimes (5–29%)
Episodic ataxia	Sometimes (5–29%)
Fewer and broader ridges in brain	Sometimes (5–29%)
Generalized brain degeneration	Sometimes (5–29%)
Generalized cerebral degeneration/underdevelopment	Sometimes (5–29%)
Generalized tonic seizure	Sometimes (5–29%)
Impulsivity	Sometimes (5–29%)
Incoordination	Sometimes (5–29%)
Infantile spasms	Sometimes (5–29%)
More active than typical	Sometimes (5–29%)
Poor fine motor coordination	Sometimes (5–29%)
Self-injurious behavior	Sometimes (5–29%)
Short attention span	Sometimes (5–29%)
Status epilepticus without prominent motor symptoms	Sometimes (5–29%)
Sudden loss of muscle tone	Sometimes (5–29%)
Tremor	Sometimes (5–29%)
Underdevelopment of part of brain called corpus callosum	Sometimes (5–29%)
Uni- and bilateral multifocal epileptiform discharges	Sometimes (5–29%)
Dystonia	Rarely (1–4%)
Repeated seizures without recovery between them	Rarely (1–4%)
Abnormal pyramidal sign	Not recorded
Developmental stagnation	Not recorded
Limb ataxia	Not recorded

Abnormality of the cardiovascular system

Trait	How often it is seen
Paroxysmal atrial fibrillation	Always
Abnormal heart rate	Often (30–79%)
Bundle branch block	Often (30–79%)
Cardiac failure	Often (30–79%)
Complete right bundle branch block	Often (30–79%)
Fainting spell	Often (30–79%)
Heart block	Often (30–79%)
Heart stops beating	Often (30–79%)
Left atrial enlargement	Often (30–79%)
Narrowing of aortic valve	Often (30–79%)
Palpitations	Often (30–79%)
Quivering upper heart chambers resulting in irregular heartbeat	Often (30–79%)
ST segment elevation	Often (30–79%)
Elevated heart rate	Sometimes (5–29%)
First degree atrioventricular block	Sometimes (5–29%)
Heart attack	Sometimes (5–29%)
Paroxysmal ventricular tachycardia	Sometimes (5–29%)
Sick sinus syndrome	Sometimes (5–29%)
Supraventricular tachycardia	Sometimes (5–29%)
Ventricular fibrillation	Sometimes (5–29%)
Hole in heart wall separating two lower heart chambers	Rarely (1–4%)
Trifascicular block	Rarely (1–4%)
Ventricular arrhythmia	Rarely (1–4%)

Abnormality of head or neck

Trait	How often it is seen
Facial tics	Often (30–79%)
Limited neck range of motion	Often (30–79%)
Drooling	Sometimes (5–29%)
Abnormally small head	Rarely (1–4%)
Cleft palate	Rarely (1–4%)
Depressed nasal bridge	Rarely (1–4%)
Nasal tip, upturned	Rarely (1–4%)
Sloping forehead	Rarely (1–4%)

Abnormality of limbs

Trait	How often it is seen
Dropped arches	Sometimes (5–29%)
Limited knee straightening	Sometimes (5–29%)
Pes valgus	Sometimes (5–29%)
Tibial torsion	Sometimes (5–29%)
Broad finger	Rarely (1–4%)
Short finger	Rarely (1–4%)
Talipes valgus	Rarely (1–4%)
Wide toe bones	Rarely (1–4%)

Abnormality of the musculoskeletal system

Trait	How often it is seen
Generalized decreased muscle tone	Always
Cogwheel rigidity	Often (30–79%)
Decreased muscle tone in infant	Often (30–79%)
Poor head control	Often (30–79%)
Rigidity	Often (30–79%)
Involuntary muscle stiffness, contraction, or spasm	Sometimes (5–29%)
Low muscle tone	Sometimes (5–29%)

Abnormality of the digestive system

Trait	How often it is seen
Abdominal pain	Often (30–79%)
Feeding difficulties	Often (30–79%)
Poor suck	Often (30–79%)
Poor swallowing	Often (30–79%)
Umbilical hernia	Rarely (1–4%)

Abnormality of the genitourinary system

Trait	How often it is seen
Renal dysplasia	Rarely (1–4%)
Short penis	Rarely (1–4%)
Ureterocele	Rarely (1–4%)

Abnormality of the integument

Trait	How often it is seen
Cyanotic episode	Sometimes (5–29%)
Paleness	Sometimes (5–29%)
Absent thumbnail	Rarely (1–4%)

Constitutional symptom

Trait	How often it is seen
Chest pain	Often (30–79%)
Decreased ability to exercise	Often (30–79%)
Fatigue	Often (30–79%)

Abnormality of blood and blood-forming tissues

Trait	How often it is seen
Thromboembolic stroke	Sometimes (5–29%)
Thromboembolism	Sometimes (5–29%)

Abnormality of the ear

Trait	How often it is seen
Dizziness	Often (30–79%)

Abnormality of the endocrine system

Trait	How often it is seen
Early onset of puberty	Rarely (1–4%)

Abnormality of the eye

Trait	How often it is seen
Cross-eyed	Rarely (1–4%)

Abnormality of the immune system

Trait	How often it is seen
Recurrent respiratory infections	Often (30–79%)

Abnormality of the respiratory system

Trait	How often it is seen
Breathing difficulty	Often (30–79%)

Growth abnormality

Trait	How often it is seen
Faltering weight	Rarely (1–4%)

How often is among people with one of the gene's conditions, the most often across them, as the Human Phenotype Ontology records it. These pages describe traits and the research behind them; they are not a diagnosis, and a doctor or genetic counsellor is the person to ask about symptoms.

Where this comes from

The Human Phenotype Ontology, release 2026-09-01: the traits linked to SCN1B and how often each is seen. Find out more at hpo.jax.org.

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