Sotos Syndrome

Sotos syndrome is a condition characterized mainly by distinctive facial features; overgrowth in childhood; and learning disabilities or delayed development. Facial features may include a long, narrow face; a high forehead; flushed (reddened) cheeks; a small, pointed chin; and down-slanting palpebral fissures. Affected infants and children tend to grow quickly; they are significantly taller than their siblings and peers and have a large head. Other signs and symptoms may include intellectual disability; behavioral problems; problems with speech and language; and/or weak muscle tone (hypotonia). Sotos syndrome is usually caused by a mutation in the NSD1 gene and is inherited in an autosomal dominant manner. About 95% of cases are due to a new mutation in the affected person and occur sporadically (are not inherited).