Koolen-de Vries Syndrome

What is Koolen-de Vries Syndrome?

Koolen-de Vries syndrome is a disorder characterized by developmental delay, mild to moderate intellectual disability, congenital malformations, and behavioral features.

People with this disorder typically have a disposition that is described as cheerful, sociable, and cooperative. They usually have weak muscle tone (hypotonia) in childhood. About half have recurrent seizures (epilepsy).

What are the symptoms of Koolen-de Vries Syndrome?

The most frequent symptoms include:

Distinctive facial features (including a high, broad forehead, droopy eyelids, a narrowing of the eye openings and outer corners of the eyes that point upward)
Developmental delay/ intellectual disability
Low muscle tone (hypotonia) in childhood
Friendly and cheerful attitude
Epilepsy
Skin and hair problems
Nasal speech
Narrow/high palate
Dental anomalies
Slender/long fingers
Joints that are too flexible (hypermobility) and/or joint dislocation or deformation
Brain anomalies
Kidney and genital anomalies

Less frequent symptoms include:

Far-sightedness (hypermetropia)
Crossed eyes (strabismus)
Narrow hands
Small hands
Heart defects
Persistence of fingertip pads
Slender lower limbs
Positional deformity of the feet
Abnormal curvature of the spine (scoliosis/kyphosis)

What causes Koolen-de Vries Syndrome?

Koolen-de Vries Syndrome is genetic syndrome involving the 17th chromosome and is caused by a microdeletion at 17q21.31 (including the KANSL1 gene) or is caused by a change or mutation of the KANSL1 gene.

How is Koolen-de Vries Syndrome diagnosed?

Besides developmental delay and intellectual disability, no single clinical feature is required to establish the diagnosis, although childhood low muscle tone is a common feature, reported in almost all affected people.

To establish the diagnosis of the syndrome one of the following is needed:

A 17q21.31 microdeletion involving at least KANSL1
A mutation in the KANSL1 gene (through an exam known as sequence analysis)

What are the treatments for Koolen-de Vries Syndrome?

For patients with Koolen-de Vries, there are several different options available for treatment.

The earliest treatment is physiotherapy for feeding problems and motor delay, followed by physical therapy aimed at strengthening the muscles. As the child grows, the therapy focuses more on developing the child’s fine and gross motor skills. Speech therapy and sign language help improve communication skills. These are aided by pictures and touch screen technology.

Patients should also seek orthopedic, cardiac, renal, and urologic care from physicians if those symptoms manifest.

Neurologists can prescribe medication to help reduce epileptic seizures.

Where can I find out more about Koolen-de Vries Syndrome?