Sotos syndrome is a rare genetic disorder characterized by excessive physical growth during the first 2 to 3 years of life. The disorder may be accompanied by mild mental retardation, delayed motor, cognitive, and social development, hypotonia (low muscle tone), and speech impairments. Children with Sotos syndrome tend to be large at birth and are often taller, heavier, and have larger heads (macrocrania) than is normal for their age. Symptoms of the disorder, which vary among individuals, include a disportionately large and long head with a slightly protrusive forehead, large hands and feet, hypertelorism (an abnormally increased distance between the eyes), and downslanting eyes. Clumsiness, an awkward gait, and unusual aggressiveness or irritability may also occur. Although most cases of Sotos syndrome occur sporadically, familial cases have also been reported.

There is no standard course of treatment for Sotos syndrome. Treatment is symptomatic.

Sotos syndrome is not a life-threatening disorder and patients may have a normal life expectancy. The initial abnormalities of Sotos syndrome usually resolve as the growth rate becomes normal after the first few years of life. Developmental delays may improve in the school-age years, however, coordination problems may persist into adulthood.

Prepared by the National Institutes of Health