Newly Diagnosed?

If you’re here because your child or loved one has just received a Kleefstra syndrome (KS) diagnosis, please know this: you are not alone. We understand how overwhelming, emotional, and confusing this moment can feel—and we want you to take a deep breath. You’ve found a community that not only shares your journey, but walks it together with compassion, information, and hope.

Welcome to your Family by Fate.

What is Kleefstra syndrome (KS)?

Kleefstra syndrome (KS) is a rare genetic disorder characterized by intellectual disability, childhood hypotonia, severe expressive speech delay and a distinctive facial appearance with a spectrum of additional clinical features. The syndrome, eponymously named for Dr. Tjitske Kleefstra, is caused by either a mutation or deletion of a gene called EHMT1 (Euchromatic Histone Methyltransferase 1). The impact leads to the loss of the entire gene.

Kleefstra Syndrome presents with a wide range of symptoms, and the severity of those symptoms vary from mild to severe.

World-Class Care & Research

Where Kleefstra Syndrome Care Happens

IDefine partners with leading medical centers advancing clinical care and research for Kleefstra syndrome — giving families real places to turn for expert support.

Boston, MA

The Kleefstra Clinic at Boston Children’s Hospital

IDefine funded the launch of this clinic in partnership with Boston Children’s Hospital — our very first initiative, and one of only a few clinics in the world built entirely around Kleefstra syndrome. It has grown into a full program of expert clinical care and active research.

Nijmegen, Netherlands

Radboud University Medical Center

Home to Dr. Tjitske Kleefstra and the team who first identified Kleefstra syndrome, Radboudumc’s Expert Center for Rare Congenital & Developmental Disorders remains a leading hub for EHMT1 research and clinical expertise in Europe.

Join the IDefine + Kleefstra Syndrome Community on Social Media

 Wherever you are in your journey, connect, share, and learn through our social platforms below.

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You Belong Here. Your Data Can Change the Future of Kleefstra Syndrome.

Whether your journey has just begun or you’re still searching for answers, IDefine is here to walk with you. We believe that empowered families drive progress — and one of the most powerful things you can do is put your family’s experience to work for research.

Below are four free, family-controlled ways to do exactly that, in the order we recommend starting them. Each does something different — and together, they’re stronger than any one alone: Ari gathers your medical records into one place you control, a CRID is one ID you create once and share with every study below, Simons Searchlight runs the natural-history study that shapes how future trials are designed, and RARE-X’s Data Collection Program sends your de-identified data straight to the biopharma companies developing treatments. Enrolling in one takes minutes — enrolling in all four means your family’s story works everywhere researchers are looking.

See it in action: watch a Kleefstra Simons Searchlight registry update or hear RARE-X present early Kleefstra results. Want to connect with another parent or get IDefine’s latest news? Email us or sign up for our newsletter any time.

Meet Ari

Citizen Health

Your free AI care advocate. Ari gathers records from every one of your child’s providers into one place, answers questions about their history in seconds, and can power research with your data — if you choose.

Get a CRID

The CRID - Clinical Research ID

A free, universal ID you create once and control. Your CRID links your family’s record across every study on this page — Simons Searchlight, RARE-X, and beyond — so you’re never re-entering the same information twice.

Join Searchlight

Simons Searchlight

The leading natural history study for EHMT1-related (Kleefstra) syndrome. Surveys and optional biosamples build the scientific record researchers use to design the next clinical trial.

Enroll in RARE-X

RARE-X

IDefine’s own Data Collection Program. Structured health surveys turn your family’s day-to-day experience into de-identified data that goes directly to the biopharma and academic researchers developing treatments.

Resources

Follow IDefine and sign up for our newsletter to stay on top of all our news, announcements and community interest stories.

Kleefstra Syndrome Facebook Pages

We are a global community! There are support groups set up as private, closed groups on Facebook for various regions around the world. 

Global Genes

Global Genes is a global non-profit advocacy organization for individuals and families fighting rare and genetic diseases.

National Organization for Rare Diseases (NORD)

NORD is a patient advocacy organization dedicated to individuals with rare diseases and the organizations that serve them. NORD’s Resource Center provides patients and caregivers with free webinars, fact sheets, infographics and other helpful materials to guide you on your journey with a rare disease.

Have a resource to suggest?
Please email us at unlock@idefine.org
Thank you!

As IDefine continues working towards our mission, we are seeking partners and volunteers who can help us raise funds and organize our efforts to build this much needed resource for the Kleefstra Syndrome community. If you would like to donate time, talent and resources to further our mission, we would love to hear from you.

Please reach out at Unlock@IDefine.org
Our Current Needs:

– IT Coordinator
– Development Director
– Data Management Coordinator
– Communications Team Member
– Fundraising Team Member

We would love to hear from you.

If you have any questions feel free to contact us. We will be sure to get back to you as soon as possible.