What is Sotos Syndrome

Sotos syndrome is a condition that causes a child to grow more quickly than other children. Children who have this condition are born with it. Increased growth starts in the womb and may continue until the child is 4 years old.

Your baby may be larger and heavier than other infants at birth, and he or she may be taller and heavier during childhood than other children. Many children with Sotos syndrome also have some delay in mental development.

Growth slows down to normal by the time a child with Sotos syndrome reaches puberty.

By this time, most children with Sotos syndrome are similar in size to other children their age. Many children with the condition also eventually catch up in mental development.

What are the causes?

Sotos syndrome is caused by a change (mutation) in a single gene (NSD1 gene) that makes a protein to control growth. The gene mutates during development in the womb (new mutation). The cause of the mutation is not known.

In most children, this gene is not passed down through families (is not inherited) because it results from a new gene mutation. However, the gene can be passed down through families once the mutation occurs.

What increases the risk?

A child may have a greater risk of Sotos syndrome if a parent has the condition.

What are the signs or symptoms?

Symptoms of this condition can be physical or behavioral and developmental. Physical symptoms include:

• Higher than normal birth weight and a head that is larger than normal.
• Yellow skin (jaundice) in infancy.
• A long, narrow face with a pointed chin and large forehead.
• Greater height and weight than other children at a similar age.
• Mild curvature of the spine (scoliosis).
• Widely spaced eyes. The outer corners may slant downward.
• Large hands and feet.
• Clumsiness.

Behavioral and developmental symptoms may include:

• Delayed speech development.
• Mild learning disabilities.
• Impulsive behaviors that are difficult to control.
• Tantrums.
• Overactivity.

How is this diagnosed?

Sotos syndrome may be diagnosed soon after birth or later in childhood if developmental delays occur.

Your child’s health care provider may suspect Sotos syndrome from your child’s head size and facial appearance. The health care provider will also do a physical exam. Your child may have tests to rule out other developmental conditions and confirm the diagnosis of Sotos syndrome. These tests include:

• X-rays to check for increased bone growth for your child’s age.
• A blood test to look for the NSD1 gene.

If a parent has Sotos syndrome, the condition can be diagnosed in a child before birth by testing womb fluid (amniotic fluid) for the NSD1 gene.

How is this treated?

There is no specific treatment for Sotos syndrome. Treatment depends on your child’s symptoms and how much they affect your child’s development. You may need to work with a team of health care providers. Treatment may include:

• Special education.
• Speech and language therapy.
• Behavioral therapy.
• Physical therapy.
• Social skills training.

Follow these instructions at home:

• Work with your child’s health care providers to find the therapy that works best for your child.
• Give your child over-the-counter and prescription medicines only as told by your child’s health care provider.
• Let your child participate in normal activities as told by your child’s health care provider. Ask your child’s health care provider what activities are safe for your child.
• Keep all follow-up visits as told by your child’s health care providers. This is important.

Contact a health care provider if:

• Your child is having behavior problems at home or at school.
• Your child is not making progress with treatment.
• You need more support at home.