Traits

Traits linked to COL3A1

collagen type III alpha 1 chain

The Human Phenotype Ontology links 140 traits to COL3A1, by body system: features seen in people with one of the gene's rare conditions.

Abnormality of the cardiovascular system

Trait	How often it is seen
Ascending aortic dissection	Always
Cerebral berry aneurysm	Always
Narrowing of pulmonic valve	Always
Varicose veins	Always
Abnormal circle of Willis morphology	Often (30–79%)
Arteriovenous fistula	Often (30–79%)
Descending aortic dissection	Often (30–79%)
High blood pressure	Often (30–79%)
Mini stroke	Often (30–79%)
Mitral valve prolapse	Often (30–79%)
Narrowing and hardening of arteries	Often (30–79%)
Telangiectasia of the skin	Often (30–79%)
Arterial dissection	Sometimes (5–29%)
Bulge in wall of large artery that carries blood away from heart	Sometimes (5–29%)
Bulge in wall of root of large artery that carries blood away from heart	Sometimes (5–29%)
Bulging of wall of large artery located above heart	Sometimes (5–29%)
Carotid cavernous fistula	Sometimes (5–29%)
Renovascular hypertension	Sometimes (5–29%)
Splenic rupture	Sometimes (5–29%)
Tear in inner wall of large artery that carries blood away from heart	Sometimes (5–29%)
Aneurysm	Not recorded
Arterial rupture	Not recorded
Brain aneurysm	Not recorded

Abnormality of head or neck

Trait	How often it is seen
Gingival recession	Always
Smooth philtrum	Always
Underdeveloped tissue around nostril	Always
Upward slanting of the opening between the eyelids	Always
Beaked nose	Often (30–79%)
Decreased volume of lip	Often (30–79%)
Little lower jaw	Often (30–79%)
Early loss of adult teeth	Sometimes (5–29%)
Gingival fragility	Sometimes (5–29%)
Gum disease	Sometimes (5–29%)
High, narrow palate	Sometimes (5–29%)
Inflamed gums	Sometimes (5–29%)
Narrow mouth	Sometimes (5–29%)
Temporomandibular joint dislocation	Sometimes (5–29%)
Absence of scalp hair	Not recorded
Dental crowding	Not recorded
Early tooth loss	Not recorded
Long face	Not recorded
Narrow nasal ridge	Not recorded
Receding chin	Not recorded
Short philtrum	Not recorded

Abnormality of the integument

Trait	How often it is seen
Atypical scarring of skin	Always
Dermal translucency	Always
Hyperelastic skin	Always
Abnormality of the skin	Very often (80–99%)
Absent/small skin	Very often (80–99%)
Fine hair	Very often (80–99%)
Irregular hyperpigmentation	Very often (80–99%)
Prematurely aged appearance	Very often (80–99%)
Thin skin	Very often (80–99%)
Excessive wrinkled skin	Often (30–79%)
Cigarette-paper scars	Sometimes (5–29%)
Hair loss	Sometimes (5–29%)
Loose redundant skin	Sometimes (5–29%)
Open skin sore	Sometimes (5–29%)
Fragile skin	Not recorded
Molluscoid pseudotumors	Not recorded
Sunken or indented skin due to damage	Not recorded

Abnormality of the nervous system

Trait	How often it is seen
Cortical dysplasia	Always
Delayed ability to sit	Always
Delayed ability to walk	Always
Typical absence seizure	Always
Ventriculomegaly	Always
Abnormal shape of brainstem	Often (30–79%)
Epilepsy	Often (30–79%)
Intellectual disability	Often (30–79%)
Weakness of one side of body	Often (30–79%)
Encephalomalacia	Sometimes (5–29%)
Delayed speech and language development	Rarely (1–4%)
Motor delay	Rarely (1–4%)
Cerebellar cyst	Not recorded
More grooves in brain	Not recorded
Small brainstem	Not recorded
Small cerebellum	Not recorded

Abnormality of limbs

Trait	How often it is seen
Club foot on both sides	Always
Increased mobility in finger joint	Always
Metacarpophalangeal joint hyperextensibility	Always
Club feet	Often (30–79%)
Short foot	Often (30–79%)
Small hand	Often (30–79%)
Dislocated hip since birth	Sometimes (5–29%)
Breakdown of small bones of fingers	Not recorded
Foot acroosteolysis	Not recorded
Long fingers	Not recorded
Slender finger	Not recorded

Abnormality of the musculoskeletal system

Trait	How often it is seen
Double-Jointed	Always
Increased mobility of hinge joints	Always
Loss of fat tissue in localized area	Very often (80–99%)
Scoliosis	Often (30–79%)
Abnormal skeletal development	Sometimes (5–29%)
Funnel chest	Sometimes (5–29%)
Joint dislocation	Sometimes (5–29%)
Tendon rupture	Sometimes (5–29%)
Increased mobility of outermost hinge joint	Not recorded
Permanent flexion of the finger or toe	Not recorded

Abnormality of the respiratory system

Trait	How often it is seen
Collapsed lung	Always
Combined cystic and ground-glass pattern on pulmonary HRCT	Always
Nodular pattern on pulmonary HRCT	Always
Spontaneous collapsed lung	Always
Emphysema	Very often (80–99%)
Coughing up blood	Often (30–79%)
Hemothorax	Often (30–79%)
Pulmonary bulla	Often (30–79%)
Repeated pneumothoraces	Often (30–79%)
Pulmonary bleb	Sometimes (5–29%)

Abnormality of blood and blood-forming tissues

Trait	How often it is seen
Bruising susceptibility	Always
Diffuse alveolar hemorrhage	Always
Low number of red blood cells or hemoglobin	Always
Internal bleeding	Often (30–79%)
Bleeding post-delivery	Sometimes (5–29%)
Bleeding within the skull	Sometimes (5–29%)
Subarachnoid hemorrhage	Sometimes (5–29%)
Ecchymosis	Not recorded
Recurrent bleeding into lungs	Not recorded

Abnormality of the eye

Trait	How often it is seen
Bulging eye	Often (30–79%)
Partial loss of field of vision	Often (30–79%)
Oculomotor nerve palsy	Sometimes (5–29%)
Bulging cornea	Rarely (1–4%)
Abnormality of eye movement	Not recorded
Deeply set eye	Not recorded
Farsightedness	Not recorded

Abnormality of the genitourinary system

Trait	How often it is seen
Undescended testes	Always
Hypospadias	Sometimes (5–29%)
Sagging uterus	Sometimes (5–29%)
Uterine rupture	Rarely (1–4%)
Bladder hernia	Not recorded
Cervical insufficiency	Not recorded

Abnormality of prenatal development or birth

Trait	How often it is seen
Premature rupture of membranes	Always
Premature birth	Often (30–79%)
Premature delivery because of cervical insufficiency or membrane fragility	Sometimes (5–29%)
Amniotic constriction ring	Rarely (1–4%)

Abnormality of the digestive system

Trait	How often it is seen
Inguinal hernia	Always
Colon perforation	Often (30–79%)
Umbilical hernia	Sometimes (5–29%)

Abnormality of the ear

Trait	How often it is seen
Absent earlobe	Not recorded

Constitutional symptom

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

Growth abnormality

Trait	How often it is seen
Short stature	Very often (80–99%)

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 COL3A1 and how often each is seen. Find out more at hpo.jax.org.

One test. A lifetime of answers.

From $449Free shipping · Results in 6–8 weeks

Get my Genome Test