Sotos syndrome is a rare genetic disorder in which an infant grows more rapidly than usual. They are usually taller and have a larger head circumference, developmental delays, and a distinctive facial appearance during childhood.

This article examines Sotos syndrome, its symptoms, causes, diagnosis, and treatment. We also look at current research, where to find support, related disorders, and the outlook for the condition.

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Sotos syndrome is a genetic disorder characterized by excessive physical growth in childhood. People with this disorder typically have a distinctive facial appearance, delayed development of mental and movement ability, and learning disabilities.

Children with Sotos syndrome may have distinctive facial features, including:

  • a prominent and high forehead
  • reddened cheeks
  • narrow, long face
  • pointed chin
  • downward slanted eyes

The facial features are typically most noticeable during childhood, and children with Sotos syndrome are generally taller than peers and siblings.

Other names

Some people also refer to the condition as:

  • Sotos sequence
  • cerebral gigantism

Over 90% of children with Sotos syndrome have the following defining characteristics:

  • distinctive facial features
  • excessive physical growth in childhood
  • delayed social, cognitive, and motor development

Other symptoms of Sotos syndrome can vary between people and may include:

  • large hands and feet
  • abnormal distance between the eyes
  • mild cognitive impairment
  • low muscle tone
  • speech impairment
  • awkward gait
  • clumsiness
  • irritability and aggression

The primary cause of Sotos syndrome is mutations in the NSD1 gene. This gene is responsible for helping make a protein that attaches to DNA and gives chromosomes their shapes. The NSD1 protein controls the activity of the genes responsible for development and growth.

Experts do not know exactly how a reduced amount of the NSD1 protein causes excessive physical growth and learning disabilities. However, they are aware that changes in the NSD1 protein disrupt the usual activity of growth and development genes.

Sotos syndrome occurs in one in 10,000 to 14,000 newborn babies, although doctors do not correctly diagnose the condition in some cases and often attribute the symptoms to other conditions.

Because of this, the true incidence of Sotos syndrome might be closer to 1 in 5,000.

A healthcare professional may suspect a child has Sotos syndrome based on the distinctive physical signs of the condition.

To diagnose the condition, a doctor will order genetic testing to identify the mutated NSD1 gene.

Learn more about genetics.

Experts have not developed any standard treatment for Sotos syndrome. However, they do treat the disorder’s symptoms.

A pediatrician will check in with children with Sotos syndrome regularly and monitor their health closely. People with severe health complications may require closer monitoring and intervention.

To treat Sotos syndrome, a doctor will refer the patient to specialists for management of the various symptoms, such as specialists in:

  • behavior
  • speech
  • learning disabilities
  • renal anomalies
  • scoliosis
  • seizures
  • cardiac abnormalities

Researchers are undertaking various studies focusing on identifying and investigating genes linked to brain development. Understanding how the genetic process can go wrong can help researchers to better understand disorders such as Sotos syndrome.

Research into specific mutations and disruptions in the specific genes involved in Sotos syndrome may help predict and develop an effective treatment.

A 2016 review also explored the incidences of certain symptoms associated with cases of Sotos syndrome. The review found that:

  • most people with Sotos syndrome have mild intellectual disability
  • people with Sotos syndrome generally have higher verbal IQ scores than performance IQ scores
  • common associated behavioral problems include aggression, attention deficit hyperactivity disorder (ADHD), and anxiety

People can find support for Sotos syndrome at:

  • March of Dimes: March of Dimes is an organization that supports mothers and babies, provides education, supports research, and leads programs for families.
  • Sotos Syndrome Support Association (SSSA): The SSSA is a non-profit organization comprised of genetic counselors, physicians, families, and healthcare agencies throughout the United States.
  • The Arc of the United States: The Arc of the United States aims to protect and promote the rights of people with intellectual and developmental disabilities.

People with Sotos syndrome often also have related disorders, which include:

Sotos syndrome is not life threatening, and people with the disorder usually have a normal life expectancy.

The initial physical symptoms of Sotos syndrome typically resolve after the first few years of life, as a child’s rate of growth levels out.

A person’s developmental delays can improve during school-age years, and adults with the syndrome may be in the average range of height and intellect, although problems with coordination may persist.

Sotos syndrome is a genetic disorder that involves excessive physical growth, distinctive facial features, and learning and developmental disabilities. The facial features typical of the syndrome are more noticeable in childhood, and children with the condition are generally taller than other children.

Mutations in specific genes cause Sotos syndrome. There is no specific treatment for Sotos syndrome, and doctors may refer people with the condition to specialists to treat specific symptoms.

The initial symptoms of the disorder typically improve during school-age years, and in adulthood, people with the disorder are generally of average height. Developmental delays can also improve.