Traits

Traits linked to LGI1

leucine rich glioma inactivated 1

The Human Phenotype Ontology links 132 traits to LGI1, by body system: features seen in people with one of the gene's rare conditions.

LGI1

Abnormality of the nervous system

Trait	How often it is seen
Absent speech development	Always
Bilateral tonic-clonic seizure with focal onset	Always
Delayed ability to sit	Always
Delayed ability to walk	Always
Delayed speech and language development	Always
EEG with focal epileptiform discharges	Always
Epilepsy	Always
Generalized clonic seizure	Always
Grand mal seizures	Always
Inability to walk by childhood/adolescence	Always
Motor delay	Always
Poor eye contact	Always
Severe global developmental delay	Always
Bilateral tonic-clonic seizure with generalized onset	Very often (80–99%)
Epileptic encephalopathy	Very often (80–99%)
Focal motor seizure	Very often (80–99%)
Generalized myoclonic seizure	Very often (80–99%)
Global developmental delay	Very often (80–99%)
Hallucinations of sound	Very often (80–99%)
Increased reflexes	Very often (80–99%)
Intellectual disability	Very often (80–99%)
Repeated seizures without recovery between them	Very often (80–99%)
Seizure affecting one half of brain	Very often (80–99%)
Degeneration of cerebrum	Often (30–79%)
Difficulty finding words	Often (30–79%)
Difficulty sleeping	Often (30–79%)
EEG abnormality	Often (30–79%)
EEG with burst suppression	Often (30–79%)
Focal autonomic seizure with epigastric sensation/nausea/vomiting/other gastrointestinal phenomena	Often (30–79%)
Focal aware seizure	Often (30–79%)
Focal aware sensory seizure with auditory features	Often (30–79%)
Focal impaired awareness seizure	Often (30–79%)
Focal sensory seizure with auditory features	Often (30–79%)
Focal tonic seizure	Often (30–79%)
Hypsarrhythmia	Often (30–79%)
Interictal epileptiform activity	Often (30–79%)
Lethargy	Often (30–79%)
Multifocal epileptiform discharges	Often (30–79%)
Abnormal autonomic nervous system physiology	Sometimes (5–29%)
Autism spectrum disorder	Sometimes (5–29%)
Brief seizures with staring spells	Sometimes (5–29%)
Choreoathetosis	Sometimes (5–29%)
CNS hypomyelination	Sometimes (5–29%)
Degeneration of cerebellum	Sometimes (5–29%)
Deja vu	Sometimes (5–29%)
Delayed CNS myelination	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%)
EEG with abnormally slow frequencies	Sometimes (5–29%)
EEG with generalized epileptiform discharges	Sometimes (5–29%)
EEG with spike-wave complexes	Sometimes (5–29%)
Episodic ataxia	Sometimes (5–29%)
Febrile seizure (within the age range of 3 months to 6 years)	Sometimes (5–29%)
Fewer and broader ridges in brain	Sometimes (5–29%)
Focal automatism seizure	Sometimes (5–29%)
Focal autonomic seizure	Sometimes (5–29%)
Focal autonomic seizure with palpitations/tachycardia/bradycardia/asystole	Sometimes (5–29%)
Focal clonic seizure	Sometimes (5–29%)
Focal sensory seizure with cephalic sensation	Sometimes (5–29%)
Focal sensory seizure with vestibular features	Sometimes (5–29%)
Focal sensory seizure with visual features	Sometimes (5–29%)
Generalized tonic seizure	Sometimes (5–29%)
Infantile spasms	Sometimes (5–29%)
Intellectual disability, mild	Sometimes (5–29%)
Jerking	Sometimes (5–29%)
Loss of developmental milestones	Sometimes (5–29%)
More active than typical	Sometimes (5–29%)
Nocturnal seizures	Sometimes (5–29%)
Self-injurious behavior	Sometimes (5–29%)
Sudden loss of muscle tone	Sometimes (5–29%)
Teeth grinding	Sometimes (5–29%)
Thin corpus callosum	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%)
Ventriculomegaly	Sometimes (5–29%)
Visual hallucinations	Sometimes (5–29%)
Behavioral abnormality	Rarely (1–4%)
Depression	Rarely (1–4%)
Dystonia	Rarely (1–4%)
Generalized-onset seizure	Rarely (1–4%)
Impulsivity	Rarely (1–4%)
Migraine	Rarely (1–4%)
Brain imaging abnormality	Not recorded

Abnormality of head or neck

Trait	How often it is seen
Small head present at birth	Always
Eye folds	Often (30–79%)
Sparse eyebrow	Often (30–79%)
Focal sensory seizure with olfactory features	Sometimes (5–29%)
Little lower jaw	Sometimes (5–29%)
Long, narrow head	Sometimes (5–29%)
Prominent metopic ridge	Sometimes (5–29%)
Wide nasal bridge	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 the musculoskeletal system

Trait	How often it is seen
Appendicular hypotonia	Always
Involuntary muscle stiffness, contraction, or spasm	Always
Low muscle tone	Always
Muscle weakness	Very often (80–99%)
Decreased muscle tone in infant	Often (30–79%)
Low muscle tone in trunk	Often (30–79%)
Muscle degeneration	Often (30–79%)
Poor head control	Often (30–79%)

Abnormality of limbs

Trait	How often it is seen
Increased muscle tone of arm or leg	Always
Broad finger	Rarely (1–4%)
Short finger	Rarely (1–4%)
Wide toe bones	Rarely (1–4%)

Abnormality of the digestive system

Trait	How often it is seen
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 cardiovascular system

Trait	How often it is seen
Glabellar hemangioma	Often (30–79%)
Hole in heart wall separating two lower heart chambers	Rarely (1–4%)

Abnormality of the ear

Trait	How often it is seen
Hearing impairment	Often (30–79%)
Large ears	Sometimes (5–29%)

Constitutional symptom

Trait	How often it is seen
Impairment of activities of daily living	Always
Sudden death	Always

Growth abnormality

Trait	How often it is seen
Faltering weight	Often (30–79%)
Short stature	Sometimes (5–29%)

Abnormality of prenatal development or birth

Trait	How often it is seen
Caesarean section	Sometimes (5–29%)

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 integument

Trait	How often it is seen
Absent thumbnail	Rarely (1–4%)

Abnormality of the respiratory system

Trait	How often it is seen
Respiratory failure	Always

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 LGI1 and how often each is seen. Find out more at hpo.jax.org.

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