Traits

Traits linked to EEFSEC

eukaryotic elongation factor, selenocysteine-tRNA specific

The Human Phenotype Ontology links 72 traits to EEFSEC, by body system: features seen in people with one of the gene's rare conditions.

Abnormality of the nervous system

Trait	How often it is seen
Abnormality of the cerebellum	Always
Cognitive impairment	Always
Degeneration of cerebellum	Always
Degeneration of cerebrum	Always
Delayed speech and language development	Always
Epilepsy	Always
Episodic ataxia	Always
Global developmental delay	Always
Increased reflexes	Always
Intellectual disability, severe	Always
IQ between 34 and 49	Always
Leg paralysis	Always
Loss of developmental milestones	Always
Motor delay	Always
Paralysis of all four limbs	Always
Peripheral neuropathy	Always
Sensory axonal neuropathy	Always
Small cerebellum	Always
Thin corpus callosum	Always
Focal impaired awareness seizure	Often (30–79%)
Difficulty articulating speech	Sometimes (5–29%)
Grand mal seizures	Sometimes (5–29%)
Inability to coordinate movements when walking	Sometimes (5–29%)
Intention tremor	Sometimes (5–29%)
Myoclonic seizure	Sometimes (5–29%)
Repeated seizures without recovery between them	Sometimes (5–29%)

Abnormality of head or neck

Trait	How often it is seen
Abnormally small head	Always
Development of small head that was not present at birth	Always
Long face	Always
Mild microcephaly	Always
Small head present at birth	Always
Thin eyebrow	Always
Abnormal facial shape	Sometimes (5–29%)
High palate	Sometimes (5–29%)
Little lower jaw	Sometimes (5–29%)
Thin red part of the upper lip	Sometimes (5–29%)

Abnormality of the musculoskeletal system

Trait	How often it is seen
Arthrogryposis multiplex congenita	Always
Funnel chest	Always
Hunched back	Always
Low muscle tone	Always
Low muscle tone in trunk	Always
Lower limb spasticity	Always
Poorly developed skeletal musculature	Always
Severely decreased muscle tone	Always
Involuntary muscle stiffness, contraction, or spasm	Often (30–79%)
Double-Jointed	Sometimes (5–29%)

Abnormality of the eye

Trait	How often it is seen
Horizontal nystagmus	Always
Visual impairment	Always
Abnormally small eyeball	Sometimes (5–29%)
Cross-eyed	Sometimes (5–29%)
Horizontal supranuclear gaze palsy	Sometimes (5–29%)
Oculomotor apraxia	Sometimes (5–29%)
Optic nerve hypoplasia	Sometimes (5–29%)
Uncoordinated eye movement	Sometimes (5–29%)

Abnormality of limbs

Trait	How often it is seen
Club feet	Sometimes (5–29%)
Curvature of little finger	Sometimes (5–29%)
Webbed fingers or toes	Sometimes (5–29%)

Laboratory abnormality

Trait	How often it is seen
Elevated creatinine	Always
Fever	Always
Increased lactate in body	Always

Abnormality of prenatal development or birth

Trait	How often it is seen
Caesarean section	Always
Feet or buttocks of fetus positioned near opening of uterus	Always

Abnormality of the cardiovascular system

Trait	How often it is seen
Patent ductus arteriosus	Always
Secundum atrial septal defect	Always

Abnormality of the ear

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

Abnormality of the integument

Trait	How often it is seen
Sparse hair	Always
Atypical nail growth	Sometimes (5–29%)

Abnormality of the digestive system

Trait	How often it is seen
Poor swallowing	Always

Abnormality of the endocrine system

Trait	How often it is seen
Decreased circulating free T4 concentration	Often (30–79%)

Abnormality of the respiratory system

Trait	How often it is seen
Apnea	Always

Growth abnormality

Trait	How often it is seen
Prenatal growth deficiency	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 EEFSEC and how often each is seen. Find out more at hpo.jax.org.

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