Traits

Traits linked to PIK3CA

phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha

The Human Phenotype Ontology links 364 traits to PIK3CA, 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
Epilepsy	Very often (80–99%)
Glioblastoma multiforme	Very often (80–99%)
Headache	Very often (80–99%)
Hyperintensity of cerebral white matter on MRI	Very often (80–99%)
Interictal EEG abnormality	Very often (80–99%)
Intracranial meningioma	Very often (80–99%)
Abnormal brain FDG positron emission tomography	Often (30–79%)
Abnormal shape of nervous system	Often (30–79%)
Absent/small cerebellum	Often (30–79%)
Anxiety	Often (30–79%)
Attention deficit	Often (30–79%)
Behavioral abnormality	Often (30–79%)
Depression	Often (30–79%)
EEG with burst suppression	Often (30–79%)
EEG with focal sharp slow waves	Often (30–79%)
EEG with focal spikes	Often (30–79%)
EEG with polyspike wave complexes	Often (30–79%)
Focal cortical dysplasia	Often (30–79%)
Focal motor seizure	Often (30–79%)
Focal T2 hyperintense brainstem lesion	Often (30–79%)
Focal T2 hypointense brainstem lesion	Often (30–79%)
Focal T2 hypointense thalamic lesion	Often (30–79%)
Global developmental delay	Often (30–79%)
Hemihypsarrhythmia	Often (30–79%)
Hemimegalencephaly	Often (30–79%)
Intellectual disability	Often (30–79%)
Irritability	Often (30–79%)
Migraine	Often (30–79%)
More grooves in brain	Often (30–79%)
Nerve tumor	Often (30–79%)
Numbness	Often (30–79%)
Pins and needles feeling	Often (30–79%)
Rise in pressure inside skull	Often (30–79%)
Seizure affecting one half of brain	Often (30–79%)
Too much cerebrospinal fluid in the brain	Often (30–79%)
Ventriculomegaly	Often (30–79%)
Abnormal central motor function	Sometimes (5–29%)
Abnormal central sensory function	Sometimes (5–29%)
Abnormal gait	Sometimes (5–29%)
Abnormal neuron shape	Sometimes (5–29%)
Abnormal pyramidal sign	Sometimes (5–29%)
Abnormal social behavior	Sometimes (5–29%)
Abnormal speech pattern	Sometimes (5–29%)
Abnormality of the cerebellum	Sometimes (5–29%)
Aplasia/Hypoplasia of the corpus callosum	Sometimes (5–29%)
Ataxia	Sometimes (5–29%)
Benign neoplasm of the central nervous system	Sometimes (5–29%)
Cancer of early nerve cells	Sometimes (5–29%)
Chiari malformation	Sometimes (5–29%)
Cognitive impairment	Sometimes (5–29%)
Cranial nerve paralysis	Sometimes (5–29%)
Difficulty articulating speech	Sometimes (5–29%)
Difficulty sleeping	Sometimes (5–29%)
Disorder of involuntary muscle movements	Sometimes (5–29%)
Disturbed sensory perception	Sometimes (5–29%)
Dysgraphia	Sometimes (5–29%)
Epileptic spasm	Sometimes (5–29%)
Fewer and broader ridges in brain	Sometimes (5–29%)
Focal tonic seizure	Sometimes (5–29%)
Gliosis	Sometimes (5–29%)
Gray matter heterotopia	Sometimes (5–29%)
Hallucinations	Sometimes (5–29%)
Intellectual disability, mild	Sometimes (5–29%)
Intellectual disability, severe	Sometimes (5–29%)
Jerking	Sometimes (5–29%)
Loss of developmental milestones	Sometimes (5–29%)
Memory impairment	Sometimes (5–29%)
Meningocele	Sometimes (5–29%)
Multiple mucosal neuromas	Sometimes (5–29%)
Myelomeningocele	Sometimes (5–29%)
Paralysis or weakness of one side of body	Sometimes (5–29%)
Pauses in breathing while sleeping	Sometimes (5–29%)
Repeated seizures without recovery between them	Sometimes (5–29%)
Spinal cord lesion	Sometimes (5–29%)
Spinal dysraphism	Sometimes (5–29%)
Spinal meningioma	Sometimes (5–29%)
Split spine	Sometimes (5–29%)
Sudden loss of muscle tone	Sometimes (5–29%)
Tethered cord	Sometimes (5–29%)
Trigeminal neuralgia	Sometimes (5–29%)
Weakness of one side of body	Sometimes (5–29%)
Astrocytoma	Rarely (1–4%)
Brain stem compression	Rarely (1–4%)
Can't control feelings	Rarely (1–4%)
Excessive daytime sleepiness	Rarely (1–4%)
Ganglioneuroma	Rarely (1–4%)
Noncancerous growth of membranes covering brain	Rarely (1–4%)
Spasms on one side of the face	Rarely (1–4%)
Transient global amnesia	Rarely (1–4%)
Cavum septum pellucidum	Not recorded
Enlarged brain	Not recorded
Intention tremor	Not recorded

Abnormality of head or neck

Trait	How often it is seen
Capillary malformation of the lip	Always
Dimple chin	Always
Enlargement of half of face	Always
Facial asymmetry	Always
Adenoma sebaceum	Very often (80–99%)
Big calvaria	Very often (80–99%)
Narrow eyelid opening	Very often (80–99%)
Wide mouth	Very often (80–99%)
Abnormality of head shape	Often (30–79%)
Abnormality of the skull	Often (30–79%)
Abnormally large tongue	Often (30–79%)
Big lower jaw	Often (30–79%)
Big maxilla	Often (30–79%)
Deviated nasal septum	Often (30–79%)
Early eruption of teeth	Often (30–79%)
Enlargement of parotid gland	Often (30–79%)
Frontal bossing	Often (30–79%)
Full cheeks	Often (30–79%)
High forehead	Often (30–79%)
Prominence of cheekbone	Often (30–79%)
Abnormality of the sense of smell	Sometimes (5–29%)
Abnormally small head	Sometimes (5–29%)
Absence of adult teeth	Sometimes (5–29%)
Adhesion of the temporomandibular joint	Sometimes (5–29%)
Bad bite	Sometimes (5–29%)
Bell's palsy	Sometimes (5–29%)
Cancer of salivary gland	Sometimes (5–29%)
Depressed nasal bridge	Sometimes (5–29%)
Increased size of tooth	Sometimes (5–29%)
Webbed neck	Sometimes (5–29%)
Neoplasm of the tongue	Rarely (1–4%)
Broad forehead	Not recorded
Decreased size of maxilla	Not recorded
Downward slanting of the opening between the eyelids	Not recorded
Enlargement of skull bones	Not recorded
Eye folds	Not recorded
Grooved tongue	Not recorded
High palate	Not recorded
Little lower jaw	Not recorded
Narrow mouth	Not recorded
Progressively abnormally enlarging cranium	Not recorded
Smooth philtrum	Not recorded

Abnormality of the cardiovascular system

Trait	How often it is seen
Cerebral cavernous malformation	Always
Strawberry birthmark	Always
Venous malformation	Always
Arteriovenous malformation	Very often (80–99%)
Lymphangioma	Very often (80–99%)
Poorly functioning veins	Very often (80–99%)
Strawberry mark	Very often (80–99%)
Telangiectasia of the skin	Very often (80–99%)
Visceral angiomatosis	Very often (80–99%)
Abnormal lymphatic vessel morphology	Often (30–79%)
Abnormality of the cerebral blood vessels	Often (30–79%)
Blood clot in artery of lung	Often (30–79%)
Collection of dilated blood vessels that forms mass	Often (30–79%)
Cutis marmorata	Often (30–79%)
Enlarged tonsils	Often (30–79%)
Varicose veins	Often (30–79%)
Vascular skin abnormality	Often (30–79%)
Abnormal cardiovascular system morphology	Sometimes (5–29%)
Abnormal heart rate	Sometimes (5–29%)
Abnormal tricuspid valve morphology	Sometimes (5–29%)
Abnormal vein	Sometimes (5–29%)
Abnormality of lung artery	Sometimes (5–29%)
Abnormality of the lymphatic system	Sometimes (5–29%)
An opening in the wall separating the top two chambers of the heart	Sometimes (5–29%)
Cardiac diverticulum	Sometimes (5–29%)
Cardiac failure	Sometimes (5–29%)
Choroidal hemangioma	Sometimes (5–29%)
Disruption of blood oxygen supply to brain	Sometimes (5–29%)
Increased spleen size	Sometimes (5–29%)
Patent ductus arteriosus	Sometimes (5–29%)
Peripheral arteriovenous fistula	Sometimes (5–29%)
Retinal cavernous hemangioma	Sometimes (5–29%)
Fainting spell	Rarely (1–4%)
Abnormality of the cardiovascular system	Not recorded
Hole in heart wall separating two lower heart chambers	Not recorded

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%)
Neoplasm of the thyroid gland	Sometimes (5–29%)
Noncancerous tumor in pituitary gland	Sometimes (5–29%)
Reduced circulating prolactin concentration	Sometimes (5–29%)
Adrenal calcification	Rarely (1–4%)
Neoplasm of the posterior pituitary	Rarely (1–4%)
Enlarged thyroid gland in neck	Not recorded
Overactive thyroid	Not recorded
Thyroid adenoma	Not recorded
Thyroid gland inflammation	Not recorded
Underactive thyroid	Not recorded

Abnormality of the genitourinary system

Trait	How often it is seen
Abnormal absence of menstruation	Often (30–79%)
Difficulty getting a full erection	Often (30–79%)
Small kidneys	Often (30–79%)
Abnormality of the menstrual cycle	Sometimes (5–29%)
Absent/small kidney	Sometimes (5–29%)
Cystic kidney disease	Sometimes (5–29%)
Endometrial carcinoma	Sometimes (5–29%)
Enlarged kidney	Sometimes (5–29%)
Epididymal cyst	Sometimes (5–29%)
Hydrocele testis	Sometimes (5–29%)
Kidney cancer	Sometimes (5–29%)
Malignant genitourinary tract tumor	Sometimes (5–29%)
Nephroblastoma	Sometimes (5–29%)
Ovarian cancer	Sometimes (5–29%)
Ovarian serous cystadenoma	Sometimes (5–29%)
Testicular lipomatosis	Sometimes (5–29%)
Urinary tract neoplasm	Sometimes (5–29%)
Loss of bladder control	Rarely (1–4%)
Cancer starting in small tubes in kidneys	Not recorded
Dysgerminoma	Not recorded
Ovarian cyst	Not recorded
Ovarian papillary adenocarcinoma	Not recorded
Transitional cell carcinoma of the bladder	Not recorded
Uterine leiomyosarcoma	Not recorded

Abnormality of limbs

Trait	How often it is seen
Asymmetric overgrowth	Always
Finger overgrowth	Always
Left and right leg differ in length or width	Always
Duplication of bones of the toes	Very often (80–99%)
Extra finger	Very often (80–99%)
Finger syndactyly	Very often (80–99%)
Fused toes	Very often (80–99%)
Unequal size of arms	Very often (80–99%)
Broad palm	Often (30–79%)
Bulbous tips of toes	Often (30–79%)
Gap between 1st and 2nd toes	Often (30–79%)
Overgrowth of one arm	Often (30–79%)
Overgrowth of one leg	Often (30–79%)
Ulnar deviation of the hand	Often (30–79%)
Cutaneous syndactyly	Sometimes (5–29%)
Decreased arm strength	Sometimes (5–29%)
Dislocated kneecap	Sometimes (5–29%)
Lower limb muscle weakness	Sometimes (5–29%)
More than five fingers or toes on hands or feet	Sometimes (5–29%)
Webbed 2nd-4th toes	Sometimes (5–29%)
Thickening of the outer layer of the skin of the palms and soles	Not recorded
Webbed fingers or toes	Not recorded

Abnormality of the eye

Trait	How often it is seen
Drooping upper eyelid	Very often (80–99%)
Bitemporal hemianopia	Often (30–79%)
Abnormal kinetic perimetry test	Sometimes (5–29%)
Amaurosis fugax	Sometimes (5–29%)
Deeply set eye	Sometimes (5–29%)
Eye muscle paralysis	Sometimes (5–29%)
Hemianopia	Sometimes (5–29%)
Oculomotor nerve palsy	Sometimes (5–29%)
Optic atrophy	Sometimes (5–29%)
Papilledema	Sometimes (5–29%)
Partial loss of field of vision	Sometimes (5–29%)
Slow decrease in sharpness of vision	Sometimes (5–29%)
Visual acuity test abnormality	Sometimes (5–29%)
Visual impairment	Sometimes (5–29%)
Weak extraocular muscles	Sometimes (5–29%)
Blindness	Rarely (1–4%)
Bulging eye	Rarely (1–4%)
Abnormally small eyeball	Not recorded
Angioid streaks	Not recorded
Close sighted	Not recorded
Clouding of the lens of the eye	Not recorded
Wide-set eyes	Not recorded

Abnormality of the musculoskeletal system

Trait	How often it is seen
Fatty lump	Always
Abnormally shaped skeletal	Very often (80–99%)
Increased adipose tissue	Very often (80–99%)
Bacterial infection of skin	Often (30–79%)
Bone overgrowth	Often (30–79%)
Double-Jointed	Often (30–79%)
Loss of fat tissue in localized area	Often (30–79%)
Low muscle tone	Often (30–79%)
Muscle weakness	Often (30–79%)
Scoliosis	Often (30–79%)
Spasticity and rigidity of muscles	Often (30–79%)
Flexed joint that cannot be straightened	Sometimes (5–29%)
Functional motor deficit	Sometimes (5–29%)
Funnel chest	Sometimes (5–29%)
Multiple fatty lumps	Sometimes (5–29%)
Narrow chest	Sometimes (5–29%)
Skeletal tumor	Sometimes (5–29%)
Abnormal formation of the hip	Rarely (1–4%)
Back pain	Rarely (1–4%)
Generalized decreased muscle tone	Not recorded
Hernia	Not recorded
Hunched back	Not recorded

Abnormality of the digestive system

Trait	How often it is seen
Abdominal pain	Very often (80–99%)
Constipation	Very often (80–99%)
Malabsorption	Very often (80–99%)
Colon cancer	Often (30–79%)
Nausea and vomiting	Often (30–79%)
Rectal tumor	Often (30–79%)
Stomach tumor	Often (30–79%)
Accumulation of fluid in the abdomen	Sometimes (5–29%)
Cancer of the pancreas	Sometimes (5–29%)
Enlarged liver	Sometimes (5–29%)
Episodic vomiting	Sometimes (5–29%)
Growths in inner lining of intestine	Sometimes (5–29%)
Hepatocellular carcinoma	Sometimes (5–29%)
Liver cancer	Sometimes (5–29%)
Pancreatic adenocarcinoma	Sometimes (5–29%)
Colonic diverticula	Not recorded
Hamartomatous polyposis	Not recorded
Hereditary nonpolyposis colorectal carcinoma	Not recorded
Micronodular cirrhosis	Not recorded
Stomach cancer	Not recorded
Subacute progressive viral hepatitis	Not recorded

Abnormality of the integument

Trait	How often it is seen
Capillary malformation	Always
port-wine stain	Very often (80–99%)
Skin cancer	Very often (80–99%)
Abnormal fat tissue distribution below the skin	Often (30–79%)
Epidermal nevus	Often (30–79%)
Hyperpigmented skin patches	Often (30–79%)
Basal cell carcinoma	Sometimes (5–29%)
Beauty mark	Sometimes (5–29%)
Hyperparakeratosis	Sometimes (5–29%)
Mole	Sometimes (5–29%)
Neurofibroma	Sometimes (5–29%)
Senile wart	Sometimes (5–29%)
Skin tags	Sometimes (5–29%)
Cutis marmorata telangiectatica congenita	Not recorded
Numerous moles	Not recorded
Subcutaneous lipoma	Not recorded

Abnormality of blood and blood-forming tissues

Trait	How often it is seen
Bleeding in brain	Very often (80–99%)
Gastrointestinal bleeding	Very often (80–99%)
Blood clot in vein	Often (30–79%)
Abnormal blood clot	Sometimes (5–29%)
Blood tumor	Sometimes (5–29%)
Hypercoagulability	Sometimes (5–29%)
Internal bleeding	Sometimes (5–29%)
Microcytic anemia	Sometimes (5–29%)
Prolonged bleeding time	Sometimes (5–29%)
Blood cancer	Not recorded

Abnormality of the respiratory system

Trait	How often it is seen
Laryngeal carcinoma	Sometimes (5–29%)
Respiratory function loss	Sometimes (5–29%)
Abnormality on pulmonary function testing	Rarely (1–4%)
Progressive pulmonary function impairment	Rarely (1–4%)
Alveolar cell carcinoma	Not recorded
Lung adenocarcinoma	Not recorded
Non-small cell lung carcinoma	Not recorded

Growth abnormality

Trait	How often it is seen
General overgrowth	Always
Uneven or disproportionate growth of one body part compared to another	Very often (80–99%)
Weight loss	Very often (80–99%)
Faltering weight	Often (30–79%)
Tall stature	Often (30–79%)
Acral overgrowth	Sometimes (5–29%)
Obesity	Sometimes (5–29%)

Abnormality of the ear

Trait	How often it is seen
Small ears	Sometimes (5–29%)
Ear pain	Rarely (1–4%)
Ringing in ears	Rarely (1–4%)
Vestibular schwannoma	Rarely (1–4%)
Hearing impairment	Not recorded
Large earlobe	Not recorded

Laboratory abnormality

Trait	How often it is seen
Swelling caused by excess lymph fluid under skin	Often (30–79%)
Blood in urine	Sometimes (5–29%)
Fluid retention	Sometimes (5–29%)
Hydrops fetalis	Sometimes (5–29%)
Increased level of L-fucose in urine	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 breast

Trait	How often it is seen
Breast cancer	Sometimes (5–29%)
Enlarged male breast	Not recorded

Constitutional symptom

Trait	How often it is seen
Fatigue	Very often (80–99%)
Pain	Sometimes (5–29%)

Abnormal tissue mass

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

Abnormality of the immune system

Trait	How often it is seen
Seborrheic dermatitis	Sometimes (5–29%)

Abnormality of the thoracic cavity

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

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 PIK3CA and how often each is seen. Find out more at hpo.jax.org.

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