- Tall stature (HP:0000098): A height above that which is expected according to age and gender norms. Evidence: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:300373)
- Elevated circulating growth hormone concentration (HP:0000845): Acromegaly is a condition resulting from overproduction of growth hormone by the pituitary gland in persons with closed epiphyses, and consists chiefly in the enlargement of the distal parts of the body. The circumference of the skull increases, the nose becomes broad, the tongue becomes enlarged, the facial features become coarsened, the mandible grows excessively, and the teeth become separated. The fingers and toes grow chiefly in thickness. Evidence: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:300373)
- Increased circulating prolactin concentration (HP:0000870): The presence of abnormally increased levels of prolactin in the blood. Prolactin is a peptide hormone produced by the anterior pituitary gland that plays a role in breast development and lactation during pregnancy. Evidence: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:300373)
- Abnormal pituitary gland morphology (HP:0012503): An anomaly of the pituitary gland. Evidence: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:300373)
- Increased circulating insulin-like growth factor 1 concentration (HP:0030269): The concentration of insulin-like growth factor 1 (IGF1) in the blood circulation is above the upper limit of normal. Evidence: TAS. Frequency: Very frequent (HP:0040281). (ORPHA:300373)
- Coarse facial features (HP:0000280): Absence of fine and sharp appearance of brows, nose, lips, mouth, and chin, usually because of rounded and heavy features or thickened skin with or without thickening of subcutaneous and bony tissues. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:300373)
- Hyperhidrosis (HP:0000975): Abnormal excessive perspiration (sweating) despite the lack of appropriate stimuli like hot and humid weather. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:300373)
- Thickened skin (HP:0001072): Laminar thickening of skin. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:300373)
- Polyphagia (HP:0002591): A neurological anomaly with gross overeating associated with an abnormally strong desire or need to eat. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:300373)
- Pituitary adenoma (HP:0002893): A benign epithelial tumor derived from intrinsic cells of the adenohypophysis (anterior pituitary). Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:300373)
- Abnormal oral glucose tolerance (HP:0004924): An abnormal resistance to glucose, i.e., a reduction in the ability to maintain glucose levels in the blood stream within normal limits following oral administration of glucose. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:300373)
- Fasting hyperinsulinemia (HP:0008283): An increased concentration of insulin in the blood in the fasting state, i.e., not as the response to food intake. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:300373)
- Sleep apnea (HP:0010535): An intermittent cessation of airflow at the mouth and nose during sleep is known as sleep apnea. Apneas that last at least 10 seconds are considered significant, but individuals with sleep apnea may experience apneas lasting from 20 seconds up to 2 or 3 minutes. Patients may have up to 15 events per hour of sleep. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:300373)
- Abnormal optic chiasm morphology (HP:0025163): A structural abnormality of the optic chiasm.The optic chiasm, located below the hypothalamus, is a partial crossing of the optic nerves. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:300373)
- Snoring (HP:0025267): Deep, noisy breathing during sleep, accompanied by hoarse or harsh sounds, is caused by the vibration of respiratory structures, especially the soft palate. This vibration results in sound due to obstructed air movement during breathing while sleeping. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:300373)
- Decreased thyroid-stimulating hormone level (HP:0031098): Reduced amount of the thyroid-stimulating hormone (TSH), which is produced by the anterior pituitary gland and stimulates the function of the thyroid gland. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:300373)
- Increased body mass index (HP:0031418): Abnormally increased weight-to-height squared ratio, calculated by dividing the individual's weight in kilograms by the square of the individual's height in meters and used as an indicator of overweight compared to averages. Evidence: TAS. Frequency: Frequent (HP:0040282). (ORPHA:300373)
- Hypogonadism (HP:0000135): A decreased functionality of the gonad. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:300373)
- Diastema (HP:0000699): Increased space between two adjacent teeth in the same dental arch. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:300373)
- Delayed puberty (HP:0000823): Passing the age when puberty normally occurs with no physical or hormonal signs of the onset of puberty. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:300373)
- Diabetes insipidus (HP:0000873): A state of excessive water intake and hypotonic (dilute) polyuria. Diabetes insipidus may be due to failure of vasopressin (AVP) release (central or neurogenic diabetes insipidus) or to a failure of the kidney to respond to AVP (nephrogenic diabetes insipidus). Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:300373)
- Abnormality of the skeletal system (HP:0000924): An abnormality of the skeletal system. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:300373)
- Acanthosis nigricans (HP:0000956): A dermatosis characterized by thickened, hyperpigmented plaques, typically on the intertriginous surfaces and neck. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:300373)
- Visual field defect (HP:0001123). Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:300373)
- Large hands (HP:0001176). Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:300373)
- Seizure (HP:0001250): A seizure is an intermittent abnormality of nervous system physiology characterized by a transient occurrence of signs and/or symptoms due to abnormal excessive or synchronous neuronal activity in the brain. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:300373)
- Ataxia (HP:0001251): Ataxia refers to impaired coordination of voluntary muscle movement. Cerebellar ataxia refers to ataxia due to dysfunction of the cerebellum. This causes a variety of elementary neurological deficits including asynergy (lack of coordination between muscles, limbs and joints), dysmetria (lack of ability to judge distances that can lead to under- or overshoot in grasping movements), and dysdiadochokinesia (inability to perform rapid movements requiring antagonizing muscle groups to be switched on and off repeatedly). Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:300373)
- Abnormality of the cardiovascular system (HP:0001626): Any abnormality of the cardiovascular system. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:300373)
- Long foot (HP:0001833): Increased back to front length of the foot. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:300373)
- Headache (HP:0002315): Cephalgia, or pain sensed in various parts of the head, not confined to the area of distribution of any nerve. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:300373)
- Abdominal distention (HP:0003270): Distention of the abdomen. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:300373)
- Adrenocorticotropic hormone deficiency (HP:0011748): A reduced ability to secrete adrenocorticotropic hormone (ACTH), a hormone that stimulates the adrenal cortex to secrete of glucocorticoids such as cortisol. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:300373)
- Enlarged pituitary gland (HP:0012505): An abnormally increased size of the pituitary gland. Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:300373)
- Hypopituitarism (HP:0040075). Evidence: TAS. Frequency: Occasional (HP:0040283). (ORPHA:300373)
- Abnormality of the nervous system (HP:0000707): An abnormality of the nervous system. Evidence: TAS. Frequency: Very rare (HP:0040284). (ORPHA:300373)
- Intellectual disability (HP:0001249): The term intellectual disability or intellectual developmental disorder is used to describe significantly sub-average intellectual and adaptive functioning based on clinical assessment and as measured by individually administered, appropriately normed, standardized and validated tests of intellectual functioning and adaptive behavior, with onset during the developmental period from infancy through adolescence. Evidence: TAS. Frequency: Very rare (HP:0040284). (ORPHA:300373)
These phenotypes are associated with the disease X-linked acrogigantism (ORPHA:300373).