Traits

Traits linked to IFIH1

interferon induced with helicase C domain 1

The Human Phenotype Ontology links 169 traits to IFIH1, 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
Degeneration of cerebrum	Always
Global developmental delay	Always
Arrhinencephaly	Very often (80–99%)
Cavity within brain	Very often (80–99%)
IQ less than 20	Very often (80–99%)
Multifocal cerebral white matter abnormalities	Very often (80–99%)
Abnormal gait	Often (30–79%)
Abnormality of extrapyramidal motor function	Often (30–79%)
Brain degeneration	Often (30–79%)
Chronic CSF lymphocytosis	Often (30–79%)
Degeneration of cerebellum	Often (30–79%)
Dystonia	Often (30–79%)
Epilepsy	Often (30–79%)
Irritability	Often (30–79%)
Leukodystrophy	Often (30–79%)
Loss of developmental milestones	Often (30–79%)
Loss of speech	Often (30–79%)
Paralysis or weakness of one side of body	Often (30–79%)
Underdevelopment of part of brain called corpus callosum	Often (30–79%)
Ventriculomegaly	Often (30–79%)
Abnormal pyramidal sign	Sometimes (5–29%)
Delayed myelination	Sometimes (5–29%)
Demyelinating peripheral neuropathy	Sometimes (5–29%)
Headache	Sometimes (5–29%)
Paralysis of all four limbs	Sometimes (5–29%)
Tetraparesis	Sometimes (5–29%)
Tremor	Sometimes (5–29%)
Degeneration of the striatum	Rarely (1–4%)
Absent speech development	Not recorded
Intellectual disability	Not recorded
Waddling gait	Not recorded

Abnormality of the musculoskeletal system

Trait	How often it is seen
Involuntary muscle stiffness, contraction, or spasm	Very often (80–99%)
Joint subluxation	Very often (80–99%)
Low muscle tone in trunk	Very often (80–99%)
Osteopenia	Very often (80–99%)
Spasticity and rigidity of muscles	Very often (80–99%)
Abnormal deposits of calcium in the brain	Often (30–79%)
Basal ganglia calcification	Often (30–79%)
Extrapyramidal muscular rigidity	Often (30–79%)
Intracerebral periventricular calcifications	Often (30–79%)
Arthritis	Sometimes (5–29%)
Low muscle tone	Sometimes (5–29%)
Lower limb spasticity	Sometimes (5–29%)
Multiple joint contractures	Sometimes (5–29%)
Muscle stiffness	Sometimes (5–29%)
Poor head control	Sometimes (5–29%)
Scoliosis	Sometimes (5–29%)
Spastic paraparesis	Sometimes (5–29%)
Spastic tetraplegia	Sometimes (5–29%)
Enchondroma	Rarely (1–4%)
Loss of fat tissue in localized area	Rarely (1–4%)
Generalized decreased muscle tone	Not recorded
Muscle fiber degeneration	Not recorded
Muscle weakness	Not recorded
Osteoporosis	Not recorded
Spastic tetraparesis	Not recorded
Tendon rupture	Not recorded

Abnormality of the cardiovascular system

Trait	How often it is seen
Enlarged liver and spleen	Often (30–79%)
Increased spleen size	Often (30–79%)
Cutis marmorata	Sometimes (5–29%)
Enlarged and thickened heart muscle	Sometimes (5–29%)
Enlarged heart	Sometimes (5–29%)
Fluid around heart	Sometimes (5–29%)
Generalized swelling of lymph nodes	Sometimes (5–29%)
High blood pressure	Sometimes (5–29%)
Hives	Sometimes (5–29%)
Inflammation of blood vessel	Sometimes (5–29%)
Raynaud phenomenon	Sometimes (5–29%)
Bulge in wall of large artery that carries blood away from heart	Rarely (1–4%)
Calcification of the aorta	Rarely (1–4%)
Moyamoya phenomenon	Rarely (1–4%)
Aortic arch calcification	Not recorded
Aortic valve calcification	Not recorded
Cardiac failure	Not recorded
Mitral valve calcification	Not recorded
Narrowing of aortic valve	Not recorded
Narrowing of blood vessel below aortic heart valve	Not recorded

Abnormality of head or neck

Trait	How often it is seen
Broad forehead	Always
High frontal hairline	Always
Recurrent viral upper respiratory tract infections	Always
Smooth philtrum	Always
Thin red part of the upper lip	Always
Decreased length of dental roots	Very often (80–99%)
Dental cavities	Very often (80–99%)
Increased thickness of skull cap	Very often (80–99%)
Abnormally small head	Often (30–79%)
Beaked nose	Often (30–79%)
Cleft eyelid	Often (30–79%)
Asymmetry of the posterior head	Sometimes (5–29%)
Small head present at birth	Sometimes (5–29%)
Decreased size of maxilla	Not recorded
Decreased size of tooth bud	Not recorded
Failure of eruption of tooth	Not recorded

Abnormality of limbs

Trait	How often it is seen
Breakdown of small bones of fingers	Very often (80–99%)
Increased muscle tone of arm or leg	Sometimes (5–29%)
Club feet	Not recorded
Coxa valga	Not recorded
Expanded metacarpals with widened medullary cavities	Not recorded
Expanded metatarsals with widened medullary cavities	Not recorded
Expanded phalanges with widened medullary cavities	Not recorded
High-arched foot	Not recorded
Hip dislocation	Not recorded
Hypoplastic distal radial epiphyses	Not recorded
Knock knees	Not recorded
Partial hip dislocation	Not recorded
Shallow acetabular fossae	Not recorded

Abnormality of the immune system

Trait	How often it is seen
Recurrent respiratory infections	Always
Recurrent viral pneumonia	Always
Autoimmunity	Often (30–79%)
Chilblains	Often (30–79%)
Increased circulating interferon-gamma concentration	Often (30–79%)
Inflammation of fat tissue	Sometimes (5–29%)
Pneumonia	Sometimes (5–29%)
Recurrent chest infections	Sometimes (5–29%)
Skin rash	Sometimes (5–29%)
Muscle inflammation	Rarely (1–4%)
Baby eczema	Not recorded

Laboratory abnormality

Trait	How often it is seen
Episodic fever	Always
Fluid retention	Often (30–79%)
High liver enzymes	Often (30–79%)
Increased CSF interferon alpha	Often (30–79%)
Unexplained fevers	Often (30–79%)
Diabetes mellitus	Sometimes (5–29%)
Elevated serum ferritin	Sometimes (5–29%)
Fatty infiltration of liver	Sometimes (5–29%)
Fever	Sometimes (5–29%)
Fluid around lungs	Sometimes (5–29%)

Abnormality of blood and blood-forming tissues

Trait	How often it is seen
Decreased blood lymphocyte number	Always
Low platelet count	Often (30–79%)
Hemolytic anemia	Sometimes (5–29%)
Low blood cell count	Sometimes (5–29%)
Low number of red blood cells or hemoglobin	Sometimes (5–29%)
Neonatal alloimmune thrombocytopenia	Sometimes (5–29%)
Rectal bleeding	Sometimes (5–29%)
Vomiting blood	Sometimes (5–29%)
Chronic lymphatic leukemia	Rarely (1–4%)

Abnormality of the digestive system

Trait	How often it is seen
Enlarged liver	Often (30–79%)
Atrophic gastritis	Sometimes (5–29%)
Bloody diarrhea	Sometimes (5–29%)
Diarrhea	Sometimes (5–29%)
Liver inflammation	Sometimes (5–29%)
Prolonged yellowing of skin in newborn	Sometimes (5–29%)
Feeding difficulties	Not recorded

Abnormality of the eye

Trait	How often it is seen
Drooping upper eyelid	Always
Abnormality of eye movement	Often (30–79%)
Glaucoma	Often (30–79%)
Developmental glaucoma	Sometimes (5–29%)
Involuntary, rapid, rhythmic eye movements	Sometimes (5–29%)
Close sighted	Not recorded

Abnormality of the integument

Trait	How often it is seen
Dry skin	Often (30–79%)
Persistent blue color of hands or feet	Sometimes (5–29%)
Detachment of nail	Not recorded
Photosensitive skin	Not recorded

Growth abnormality

Trait	How often it is seen
Prenatal growth deficiency	Often (30–79%)
Short stature	Often (30–79%)
Weight loss	Sometimes (5–29%)
Decreased body weight	Not recorded

Abnormal cellular phenotype

Trait	How often it is seen
Decreased circulating IgG3 concentration	Always
Increased circulating IgG3 concentration	Always
Increased antibody level in blood	Sometimes (5–29%)

Abnormality of the respiratory system

Trait	How often it is seen
Breathing difficulties	Always
Ground-glass opacification	Always
Respiratory failure	Always

Abnormality of the genitourinary system

Trait	How often it is seen
Nephrotic syndrome	Sometimes (5–29%)
Short penis	Sometimes (5–29%)

Abnormality of prenatal development or birth

Trait	How often it is seen
Low levels of amniotic fluid	Often (30–79%)

Abnormality of the ear

Trait	How often it is seen
Low-set ears	Sometimes (5–29%)

Abnormality of the endocrine system

Trait	How often it is seen
Underactive thyroid	Sometimes (5–29%)

Abnormality of the voice

Trait	How often it is seen
Hoarse voice	Sometimes (5–29%)

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 IFIH1 and how often each is seen. Find out more at hpo.jax.org.

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