overgrowth syndrome

overgrowth syndrome A condition with multiple features, most notably excessive growth. A number of overgrowth syndromes affect children, such as fragile X syndrome. Excessive growth of specific body parts is also a feature of a number of disorders, such as Beckwith-Wiedemann syndrome, in which there is macroglossia (a large tongue due to overgrowth of the tongue). Overactivity of the pituitary gland with overproduction of growth hormone causes overgrowth before adolescence and a distinctive pattern of overgrowth called acromegaly. See also acromegaly; fragile X syndrome.