Koolen-de Vries Syndrome

What is Koolen-de Vries syndrome?

Koolen-de Vries syndrome (KdVS) is a rare genetic condition that causes a wide range of symptoms beginning in infancy or childhood. Its symptoms include developmental delays, intellectual disability, hypotonia, specific facial features and often epilepsy.

Children with KdVS usually have a cheerful and friendly nature. However, these symptoms have a lifelong impact on both the child and family unit.

What causes Koolen-de Vries syndrome?

For most children, KdVS results from a missing gene called KANSL1 on 1 copy of the 17th chromosome. For other children, a genetic change (variant) in the KANSL1 gene causes the condition. The KANSL1 gene contains instructions for making a protein that helps many parts of the body develop and work properly, including the brain.

The genetic change that causes KdVS usually happens randomly. This means the child has no family history of the condition. But some children may inherit the mutated or missing gene from 1 of their parents.

What are the signs and symptoms of Koolen-de Vries syndrome?

Children with KdVS often have a wide range of symptoms affecting many different areas of the body. Symptoms vary between children.

Developmental symptoms

KdVS often impacts a child’s development, causing symptoms that may include:

• Delayed motor skills like head control, sitting, standing and walking
• Intellectual and learning disabilities (typically mild or moderate)
• Speech and language delays

Distinctive facial features

Children with KdVS usually have certain characteristic facial features, including:

• Broad forehead
• Droopy eyelids
• Long face
• Pear-shaped nose
• Prominent ears

Other symptoms

Many children with KdVS also have one or more of these symptoms:

• Feeding difficulties in infancy
• Low muscle tone (hypotonia)
• Recurrent seizures (epilepsy)

Some children with KdVS have less common symptoms such as:

• Heart defects
• Kidney problems
• Spine conditions such as short stature or a curved spine (scoliosis)

How do we diagnose Koolen-de Vries syndrome?

To diagnose KdVS, our doctors will review your child’s:

• Medical history
• Signs and symptoms during a physical exam

If we think your child may have KdVS, we can confirm the diagnosis with one of these simple blood tests that look at your child’s genetics:

• Chromosome microarray: This test checks whether a small piece of chromosome 17 is missing.
• Gene sequencing: Tests such as whole exome or whole genome sequencing look for changes to the KANSL1 gene.

How do we treat Koolen-de Vries syndrome?

Our care team will create an individual care plan based on your child’s specific symptoms and needs. Your child’s comprehensive treatment plan may include:

• Antiseizure medicines to treat epilepsy
• Behavioral support, such as social skills training
• Educational support, such as special education services or an individualized education plan (IEP)
• Occupational therapy to help with everyday activities
• Physical therapy to help with developmental delays and strengthen muscles
• Speech-language therapy to help with speech and language development

We also regularly monitor your child to look for heart, kidney, orthopedic or developmental concerns.

Why choose us for treatment of Koolen-de Vries syndrome?

U.S. News & World Report consistently ranks our program among the top hospitals in the nation for neurology. As the first clinic in the U.S. to focus on KdVS, the team at our Kool Clinic is specially trained to diagnose and treat this condition.

At Children’s Hospital Colorado, your child gets comprehensive, specialized care from a multidisciplinary team made up of: 

• Genetic counselors 
• Neurologists 
• Neuropsychologists 
• Nurse coordinators 
• Rehabilitative medicine specialists 
• Physical, Occupational, and Speech Therapists 
• Special Care Pediatricians 
• Research coordinators 

To make an appointment with our Kool Clinic, a KdVS center of excellence, please call 720-777-1326.

Helpful resources

• Koolen-de Vries Syndrome Foundation
• National Organization for Rare Disorders

What can I expect during a Koolen-de Vries syndrome visit?

You and your child will meet with our care team during your 1-2-day visit to the Kool Clinic. Often on the first day, depending on availability, you’ll meet with a neuropsychologist so we can learn more about your child’s thinking, learning, memory and other cognitive skills.

We may also conduct 1 or more assessments to help us get to know your child better and learn about their unique needs. These assessments may include:

• Bayley Scales of Infant and Toddler Development
• Vineland Adaptive Behavior Scales
• Wechsler Intelligence Scales (WISP or WISC)

On the second day, you and your child will have appointments with a wide range of specialists, including:

• Developmental pediatricians or pediatric psychologists
• Genetic counselors
• Pediatric neurologists
• Pediatric epileptologists
• Physical, occupational and speech therapists
• Rehabilitation medicine specialists

Is there a cure for Koolen-de Vries syndrome?

Currently, there is no cure for KdVS. Our care team will develop a care plan unique to your child. Together, we can manage your child’s symptoms and enhance their quality of life.