Traits

Traits linked to SMC5

structural maintenance of chromosomes 5

The Human Phenotype Ontology links 42 traits to SMC5, by body system: features seen in people with one of the gene's rare conditions.

Abnormality of head or neck

Trait	How often it is seen
Abnormally small head	Often (30–79%)
Bulbous nose	Sometimes (5–29%)
Dacryocystocele	Sometimes (5–29%)
Downturned corners of mouth	Sometimes (5–29%)
Eye folds	Sometimes (5–29%)
Frontal bossing	Sometimes (5–29%)
Full lower lip	Sometimes (5–29%)
Gap between teeth	Sometimes (5–29%)
High palate	Sometimes (5–29%)
Little lower jaw	Sometimes (5–29%)
Long face	Sometimes (5–29%)
Prominent nose	Sometimes (5–29%)
Short opening between the eyelids	Sometimes (5–29%)
Triangular face	Sometimes (5–29%)

Abnormality of the nervous system

Trait	How often it is seen
Anxiety	Often (30–79%)
Motor delay	Often (30–79%)
Attention deficit	Sometimes (5–29%)
Brisk reflexes	Sometimes (5–29%)
Encephalopathy	Sometimes (5–29%)
Epilepsy	Sometimes (5–29%)
Lack of coordination of movement	Sometimes (5–29%)

Abnormality of blood and blood-forming tissues

Trait	How often it is seen
Low number of red blood cells or hemoglobin	Sometimes (5–29%)
Low platelet count	Sometimes (5–29%)
Vitreous hemorrhage	Sometimes (5–29%)

Abnormality of limbs

Trait	How often it is seen
Curvature of digit	Often (30–79%)
Dropped arches	Often (30–79%)
Single transverse palmar crease	Sometimes (5–29%)

Abnormality of the cardiovascular system

Trait	How often it is seen
Narrowing of pulmonic valve	Sometimes (5–29%)
Patent ductus arteriosus	Sometimes (5–29%)
Supravalvar pulmonary stenosis	Sometimes (5–29%)

Abnormality of the eye

Trait	How often it is seen
Remnants of the hyaloid vascular system	Often (30–79%)
Abnormally small eyeball	Sometimes (5–29%)
Clouding of the lens of the eye at birth	Sometimes (5–29%)

Abnormality of the ear

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

Abnormality of the breast

Trait	How often it is seen
Enlarged male breast	Sometimes (5–29%)

Abnormality of the digestive system

Trait	How often it is seen
Acid reflux	Sometimes (5–29%)

Abnormality of the endocrine system

Trait	How often it is seen
Elevated circulating thyroid-stimulating hormone concentration	Often (30–79%)

Abnormality of the integument

Trait	How often it is seen
Spinal dimple	Sometimes (5–29%)

Abnormality of the musculoskeletal system

Trait	How often it is seen
Hunched back	Sometimes (5–29%)

Abnormality of the respiratory system

Trait	How often it is seen
Breathing difficulty	Sometimes (5–29%)

Laboratory abnormality

Trait	How often it is seen
Hyperinsulinemia	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 SMC5 and how often each is seen. Find out more at hpo.jax.org.

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