Sotos Syndrome

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What is Sotos syndrome?

Sotos syndrome (also known as cerebral gigantism) is a rare genetic disorder caused by mutation in the NSD1 gene on chromosome 5. It is characterized by excessive physical growth during the first few years of life. 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 disproportionately large and long head with a slightly protrusive forehead and pointed chin
  • Large hands and feet
  • Hypertelorism (an abnormally increased distance between the eyes)
  • Down-slanting eyes

The disorder is often accompanied by:

  • Mild cognitive impairment
  • Delayed motor, cognitive, and social development
  • Hypotonia (low muscle tone)
  • Speech impairments

Clumsiness, an awkward gait, and unusual aggressiveness or irritability may also occur. Although most cases of Sotos syndrome occur sporadically (meaning they are not known to be inherited), familial cases also have been reported.

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

Sotos syndrome is not a life-threatening disorder and individuals with the disorder 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, and adults with Sotos syndrome are likely to be within the normal range for intellect and height. However, coordination problems may persist into adulthood.

Learn About Clinical Trials
Clinical trials are studies that allow us to learn more about disorders and improve care. They can help connect patients with new and upcoming treatment options.

How can I or my loved one help improve care for people with Sotos syndrome?

Consider participating in a clinical trial so clinicians and scientists can learn more about Sotos syndrome and related disorders. Clinical research uses human volunteers to help researchers learn more about a disorder and perhaps find better ways to safely detect, treat, or prevent disease.

All types of volunteers are needed—those who are healthy or may have an illness or disease—of all different ages, sexes, races, and ethnicities to ensure that study results apply to as many people as possible, and that treatments will be safe and effective for everyone who will use them.

For information about participating in clinical research visit NIH Clinical Research Trials and You. Learn about clinical trials currently looking for people with Sotos syndrome at


Where can I find more information about Sotos syndrome?

The following organizations and resources help people living with Sotos syndrome and their families, friends, and caregivers:

March of Dimes
Phone: 888-663-4637

Sotos Syndrome Support Association
Phone: 888-246-7772

The Arc of the United States
Phone: 800-433-5255 or 202-534-3700



Information about Sotos syndrome is also available:


Order publications from the NINDS Catalog
The NINDS Publication Catalog offers printed materials on neurological disorders for patients, health professionals, and the general public. All materials are free of charge, and a downloadable PDF version is also available for most publications.