Home

Kleefstra Syndrome

Information for families, caregivers, and healthcare professionals. 

Kleefstra syndrome is a rare genetic neurodevelopmental disorder primarily associated with mutations in the gene EHMT1. On this website, you will find up-to-date information on the diagnosis and characteristics of the syndrome, international care guidelines, and the latest research on the syndrome.

Learn about the syndrome

What is Kleefstra syndrome?;

Basic and up-to-date information on KLEFS1, the gene EHMT1, the genetic cause and the most common characteristics of the syndrome. Read about the diagnosis,
What does his simple inadequacy mean? EHMT1 and because the clinical presentation can vary significantly from person to person.

Learn more

Was the diagnosis just made?;

The initial period following a diagnosis is usually marked by many questions.
What tests are needed? Is it hereditary?;
What do we know about speech, sleep, and regression? Is there a treatment?; 
We've compiled the most common questions families have in one place, with answers based on the latest international guidelines.

Frequently Asked Questions

Care Instructions 2026

In 2026, the first international evidence-based clinical guidelines specifically for type 1 Kleefstra syndrome were published. They include 66 practical recommendations on diagnosis, development and communication, epilepsy, sleep, mental health, cardiac and metabolic monitoring, and family support throughout the patient’s life.

See the instructions

A personal story that became a call to action

kleefstrasyndrome.com was created based on our family's personal experience with Kleefstra syndrome.

When Christina was diagnosed, there was very little information available in Greek, and much of the scientific knowledge was difficult to find or understand for a Greek family that had just been confronted with such a rare diagnosis. This is how the initial desire arose to create a space where other families could find answers and connect with one another, and subsequently, the need to gather reliable information about the syndrome in Greek in one place.

Today, the goal of this website is to clearly present not only what we know, but also what we do not yet know about Kleefstra syndrome.

Our story

Latest Updates on the Investigation

All the latest research news

The Kleefstra Syndrome Worldwide Map It is an international initiative of IDefine that maps the presence of individuals with Kleefstra Syndrome worldwide.

By registering families, a more comprehensive picture of the global community is created, helping to raise awareness of the syndrome and support education, networking, and the planning of future research initiatives.

Every new entry counts, and the participation of families from Greece is important.

View the map and register

The latest news from conferences and actions

Read the community news