GIGANTISM. — The term denotes a particular development of bodily proportions, especially height, that exceeds the limits of normal individual variability.
Human stature is a variable element within fixed bounds determined by climatic and hereditary factors, particularly race. Excluding the extreme measurements typical of certain peoples—African Pygmies (Akka) with an average height of 138 cm, and Scots from Galloway and the north with an average height of 178–79 cm—it can be said that normal variations in human height range between 154 and 175 cm, with an average of 165 cm. A significant deviation from this average leads to abnormal conditions: in dwarfism (v.), with a height below 125 cm, and in gigantism, with a height above 199 cm.
In gigantism, stature may reach or exceed two and a half meters, while the proportions of the other body diameters remain harmonious, or the body may exhibit a particular disharmony due to the addition of acromegalic traits (v. ENDOCRINE, GLANDOLE, GLANDS). It rarely runs in families; in its pure form, it is exclusive to the male sex and represents a genuine mark of physical inferiority for the individual. Indeed, in one-third of cases, the subject suffers from diabetes, is muscularly asthenic, shows particular organic fragility, resists diseases poorly, has limited mental capacity ("homo longus raro sapiens"), and exhibits weak willpower. To this clinical picture, signs of infantilism and hypogenitalism with impotence (v.) are often associated. The life of giants is short; they rarely surpass 30–40 years. This contrasts sharply with mythological and heroic descriptions, which portrayed giants as beings of exceptional physical strength and supernormal valor.
Gigantism is currently attributed exclusively to hyperfunction of the anterior portion of the pituitary gland, with overproduction of the growth hormone (somatotrophic hormone, STH), which exerts a stimulating effect on skeletal development.