Traits

Traits linked to SMARCB1

SWI/SNF related BAF chromatin remodeling complex subunit B1

The Human Phenotype Ontology links 185 traits to SMARCB1, 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
Abnormal corpus callosum morphology	Always
Global developmental delay	Always
Schwannoma	Always
Intracranial meningioma	Very often (80–99%)
Irritability	Very often (80–99%)
Lack of feeling, emotion, interest	Very often (80–99%)
Malignant neoplasm of the central nervous system	Very often (80–99%)
Abnormal brain FDG positron emission tomography	Often (30–79%)
Ataxia	Often (30–79%)
Behavioral abnormality	Often (30–79%)
Disturbances of consciousness	Often (30–79%)
Epilepsy	Often (30–79%)
Focal T2 hypointense thalamic lesion	Often (30–79%)
Headache	Often (30–79%)
Intellectual disability, severe	Often (30–79%)
IQ between 34 and 49	Often (30–79%)
Migraine	Often (30–79%)
Paralysis or weakness of one side of body	Often (30–79%)
Seizure affecting one half of brain	Often (30–79%)
Small cerebellum	Often (30–79%)
Spinal cord tumor	Often (30–79%)
Too much cerebrospinal fluid in the brain	Often (30–79%)
Abnormal central motor function	Sometimes (5–29%)
Abnormal central sensory function	Sometimes (5–29%)
Abnormal gait	Sometimes (5–29%)
Abnormality of the cerebellum	Sometimes (5–29%)
Absent speech development	Sometimes (5–29%)
Agenesis of corpus callosum	Sometimes (5–29%)
Aggressive behavior	Sometimes (5–29%)
Autism spectrum disorder	Sometimes (5–29%)
Cerebral palsy	Sometimes (5–29%)
Cognitive impairment	Sometimes (5–29%)
Cranial nerve paralysis	Sometimes (5–29%)
Memory impairment	Sometimes (5–29%)
More active than typical	Sometimes (5–29%)
Oral aversion	Sometimes (5–29%)
Pins and needles feeling	Sometimes (5–29%)
Rise in pressure inside skull	Sometimes (5–29%)
Simplified gyral pattern	Sometimes (5–29%)
Spinal meningioma	Sometimes (5–29%)
Trigeminal neuralgia	Sometimes (5–29%)
Weakness of one side of body	Sometimes (5–29%)
Abnormal speech pattern	Rarely (1–4%)
Brain stem compression	Rarely (1–4%)
Can't control feelings	Rarely (1–4%)
Excessive daytime sleepiness	Rarely (1–4%)
Muscle twitch	Rarely (1–4%)
Noncancerous growth of membranes covering brain	Rarely (1–4%)
Numbness	Rarely (1–4%)
Spasms on one side of the face	Rarely (1–4%)
Transient global amnesia	Rarely (1–4%)
Choroid plexus carcinoma	Not recorded
Intellectual disability	Not recorded
Medulloblastoma	Not recorded

Abnormality of head or neck

Trait	How often it is seen
Coarse facial features	Always
Delayed eruption of permanent teeth	Always
Full lips	Always
High palate	Always
Long eyelashes	Always
Sparse scalp hair	Always
Thick eyebrow	Always
Wide mouth	Always
Wide nose	Always
Full lower lip	Very often (80–99%)
Prominent eyelashes	Very often (80–99%)
Abnormal facial shape	Often (30–79%)
Abnormally large tongue	Often (30–79%)
Abnormally small head	Often (30–79%)
Big calvaria	Often (30–79%)
Broad nasal tip	Often (30–79%)
Broad philtrum	Often (30–79%)
Cleft palate	Often (30–79%)
Delayed eruption of teeth	Often (30–79%)
Depressed nasal bridge	Often (30–79%)
Long philtrum	Often (30–79%)
Low frontal hairline	Often (30–79%)
Nasal tip, upturned	Often (30–79%)
Recurrent colds	Often (30–79%)
Short nose	Often (30–79%)
Thick nasal alae	Often (30–79%)
Thin red part of the upper lip	Often (30–79%)
Wide nasal base	Often (30–79%)
Abnormality of the sense of smell	Sometimes (5–29%)
Bell's palsy	Sometimes (5–29%)
Dandy-Walker malformation	Sometimes (5–29%)
Neoplasm of the tongue	Rarely (1–4%)

Abnormality of the endocrine system

Trait	How often it is seen
Decreased circulating ACTH concentration	Often (30–79%)
Decreased circulating follicle stimulating hormone concentration	Often (30–79%)
Decreased circulating luteinizing hormone level	Often (30–79%)
Decreased serum estradiol	Often (30–79%)
Decreased serum testosterone level	Often (30–79%)
Hypogonadotropic hypogonadism	Often (30–79%)
Increased circulating prolactin concentration	Often (30–79%)
Low blood cortisol level	Often (30–79%)
Low thyroid gland function due to abnormal pituitary gland	Often (30–79%)
Secondary growth hormone deficiency	Often (30–79%)
Abnormal hypothalamus physiology	Sometimes (5–29%)
Enlarged pituitary gland	Sometimes (5–29%)
Hypothalamic hypothyroidism	Sometimes (5–29%)
Neoplasm of the anterior pituitary	Sometimes (5–29%)
Reduced circulating prolactin concentration	Sometimes (5–29%)
Neoplasm of the posterior pituitary	Rarely (1–4%)
Papillary thyroid carcinoma	Rarely (1–4%)

Abnormality of the eye

Trait	How often it is seen
Bitemporal hemianopia	Often (30–79%)
Cross-eyed	Often (30–79%)
Drooping upper eyelid	Often (30–79%)
Visual impairment	Often (30–79%)
Abnormal kinetic perimetry test	Sometimes (5–29%)
Close sighted	Sometimes (5–29%)
Clouding of the lens of the eye	Sometimes (5–29%)
Eye muscle paralysis	Sometimes (5–29%)
Oculomotor nerve palsy	Sometimes (5–29%)
Papilledema	Sometimes (5–29%)
Slow decrease in sharpness of vision	Sometimes (5–29%)
Visual acuity test abnormality	Sometimes (5–29%)
Weak extraocular muscles	Sometimes (5–29%)
Blindness	Rarely (1–4%)
Bulging eye	Rarely (1–4%)

Abnormality of the musculoskeletal system

Trait	How often it is seen
Delayed bone maturation	Always
Low muscle tone	Always
Decreased muscle tone in infant	Often (30–79%)
Double-Jointed	Often (30–79%)
Limitation of joint mobility	Often (30–79%)
Muscle weakness	Often (30–79%)
Scoliosis	Often (30–79%)
Abnormal deposits of calcium in the brain	Sometimes (5–29%)
Central diaphragmatic hernia	Sometimes (5–29%)
Fatty lump	Sometimes (5–29%)
Functional motor deficit	Sometimes (5–29%)
Hernia	Sometimes (5–29%)
Back pain	Rarely (1–4%)

Abnormality of the cardiovascular system

Trait	How often it is seen
Abnormality of the heart	Often (30–79%)
An opening in the wall separating the top two chambers of the heart	Sometimes (5–29%)
Hole in heart wall separating two lower heart chambers	Sometimes (5–29%)
Lumbosacral hemangioma	Sometimes (5–29%)
Patent ductus arteriosus	Sometimes (5–29%)
Tetralogy of Fallot	Sometimes (5–29%)
Fainting spell	Rarely (1–4%)
Abnormal cardiovascular system morphology	Not recorded

Abnormality of the genitourinary system

Trait	How often it is seen
Abnormal absence of menstruation	Often (30–79%)
Abnormality of the genitourinary system	Often (30–79%)
Difficulty getting a full erection	Often (30–79%)
Undescended testes	Often (30–79%)
Horseshoe kidney	Sometimes (5–29%)
Hypospadias	Sometimes (5–29%)
Uterine leiomyoma	Sometimes (5–29%)
Loss of bladder control	Rarely (1–4%)

Abnormality of the integument

Trait	How often it is seen
Peripheral schwannoma	Always
Excessive hair growth	Very often (80–99%)
Small nail	Very often (80–99%)
Excessive hairiness	Often (30–79%)
Small fifth toenail	Often (30–79%)
Underdeveloped fifth fingernail	Often (30–79%)
Neurofibroma	Sometimes (5–29%)
Skin cancer	Rarely (1–4%)

Abnormality of limbs

Trait	How often it is seen
Short outermost little finger bone	Always
Curvature of digit	Often (30–79%)
Short 5th finger	Often (30–79%)
Decreased arm strength	Sometimes (5–29%)
Lower limb muscle weakness	Sometimes (5–29%)

Abnormality of the digestive system

Trait	How often it is seen
Feeding difficulties	Always
Poor suck	Always
Nausea and vomiting	Very often (80–99%)
Inguinal hernia	Often (30–79%)
Hepatoblastoma	Rarely (1–4%)

Growth abnormality

Trait	How often it is seen
Short stature	Always
Growth delay	Often (30–79%)
Growth delay as children	Often (30–79%)
Prenatal growth deficiency	Often (30–79%)
Obesity	Sometimes (5–29%)

Abnormality of the ear

Trait	How often it is seen
Hearing impairment	Often (30–79%)
Ringing in ears	Sometimes (5–29%)
Ear pain	Rarely (1–4%)
Bilateral vestibular schwannoma	Not recorded

Abnormal cellular phenotype

Trait	How often it is seen
Chromosomal breakage induced by ionizing radiation	Very often (80–99%)
Increased sensitivity to ionizing radiation	Very often (80–99%)

Abnormality of the immune system

Trait	How often it is seen
Aspiration pneumonia	Often (30–79%)
Recurrent infections	Often (30–79%)

Abnormality of the respiratory system

Trait	How often it is seen
Abnormality on pulmonary function testing	Rarely (1–4%)
Progressive pulmonary function impairment	Rarely (1–4%)

Abnormal tissue mass

Trait	How often it is seen
Abnormal tissue mass	Sometimes (5–29%)

Abnormality of blood and blood-forming tissues

Trait	How often it is seen
Bleeding in brain	Rarely (1–4%)

Abnormality of the thoracic cavity

Trait	How often it is seen
Abnormal mediastinum morphology	Rarely (1–4%)

Abnormality of the voice

Trait	How often it is seen
Weak voice	Rarely (1–4%)

Constitutional symptom

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

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 SMARCB1 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