Koolen-de Vries syndrome (KDVS)

What is Koolen-de Vries syndrome (KDVS)?

Koolen-de Vries syndrome is a rare genetic condition believed to occur in 1 in every 55,000 people. It is a recently discovered condition, and was first identified in 2006.

Characteristic features of the syndrome include mild-moderate intellectual disability with developmental delay. Low muscle tone in childhood is also a defining symptom of the syndrome.

Individuals with the syndrome are often described as having a sociable, happy personality.

What gene changes cause Koolen-de Vries syndrome (KDVS)?

The syndrome is caused by either a microdeletion of a small part of chromosome 17, or by a mutation of the KANSL1 gene.

The deletions or mutations that cause the syndrome are random and the majority of individuals are the first in their family with the syndrome.

Microdeletion inheritance occurs when there is a deletion of several genes on a chromosome. The specific chromosome on which the deletions occur will determine the syndrome they cause.

n some cases, a genetic syndrome may be the result of a de-novo mutation and the first case in a family. In this case, this is a new gene mutation which occurs during the reproductive process.

What are the main symptoms of Koolen-de Vries syndrome (KDVS)?

Facial and physical characteristics include a pear-shaped nose, long face, broad forehead, droopy eyelids and very prominent ears.

Other health conditions may include epilepsy, estimated to be a major symptom in 50% of individuals diagnosed with the syndrome.

Heart defects, kidney disease and bone abnormalities are also recognized symptoms in some affected individuals.

How does someone get tested for Koolen-de Vries syndrome (KDVS)?

The initial testing for Koolen-de Vries syndrome can begin with facial analysis screening, through the FDNA Telehealth telegenetics platform, which can identify the key markers of the syndrome and outline the need for further testing. A consultation with a genetic counselor and then a geneticist will follow. 

Based on this clinical consultation with a geneticist, the different options for genetic testing will be shared and consent will be sought for further testing.   ed.

Get Faster and More Accurate Genetic Diagnosis!

More than 250,000 patients successfully analyzed!
Don't wait years for a diagnosis. Act now and save valuable time.

Start Here!

"Our road to a rare disease diagnosis was a 5-year journey that I can only describe as trying to take a road trip with no map. We didn’t know our starting point. We didn’t know our destination. Now we have hope."


Paula and Bobby
Parents of Lillie

What is FDNA Telehealth?

FDNA Telehealth is a leading digital health company that provides faster access to accurate genetic analysis.

With a hospital technology recommended by leading geneticists, our unique platform connects patients with genetic experts to answer their most pressing questions and clarify any concerns they may have about their symptoms.

Benefits of FDNA Telehealth


Our platform is currently used by over 70% of geneticists and has been used to diagnose over 250,000 patients worldwide.


FDNA Telehealth provides facial analysis and screening in minutes, followed by fast access to genetic counselors and geneticists.

Ease of Use

Our seamless process begins with an initial online diagnosis by a genetic counselor and follows by consultations with geneticists and genetic testing.

Accuracy & Precision

Advanced artificial intelligence (AI) capabilities and technology with a 90% accuracy rate for a more accurate genetic analysis.

Value for

Faster access to genetic counselors, geneticists, genetic testing, and a diagnosis. As fast as within 24 hours if required. Save time and money.

Privacy & Security

We guarantee the utmost protection of all images and patient information. Your data is always safe, secure, and encrypted.

FDNA Telehealth can bring you closer to a diagnosis.
Schedule an online genetic counseling meeting within 72 hours!