Kleefstra Syndrome Awareness Day is September 17 — Give Today

Kleefstra Syndrome Awareness Day is September 17! One day a year, our community gets to decide how loud it is — and this year we are asking you to make it count.

Earlier this month, families, self-advocates, researchers, and clinicians came together in Waltham, Massachusetts for the 2026 Kleefstra Syndrome Family Conference and Scientific Summit. The talks from that weekend are now online, free, and open to anyone. When we asked attendees afterward what they would remember most, almost none of them named a session. They named each other.

That is what your gift builds.

IDefine is the leading nonprofit patient advocacy organization dedicated to advancing research, building community, and driving progress toward new treatments — and eventually a cure — for Kleefstra syndrome (KS). Founded in 2020 by parents of children diagnosed with KS, we bring urgency, determination, and a deeply personal commitment to changing outcomes for every family living with this condition.

Advancing Research, Together

In just a few years, IDefine has helped build the scientific and clinical foundation needed to pursue real treatments — funding and helping establish the first dedicated Kleefstra Syndrome Center of Excellence at Boston Children's Hospital, supporting natural history studies, and developing patient-derived research models used by scientists around the world. Today, that foundation is powering the next generation of research, including strategic collaborations with Unravel Biosciences, UT Southwestern, and the University of Chicago exploring gene therapy and other promising paths to treatment. With continued investment, we believe meaningful treatments could be possible within the next five years.

Building a Connected Community

None of this is possible without community. Through conferences, connection, and shared knowledge, IDefine ensures no family faces Kleefstra syndrome alone — bringing patients, caregivers, clinicians, and researchers together to support one another and drive progress side by side.

What Your Gift Does

Funds research. We fund the science that moves Kleefstra syndrome toward treatment — natural history studies, patient-derived research models, and gene therapy work with partners at Unravel Biosciences, UT Southwestern, and the University of Chicago.

Builds centers of excellence. We funded and helped establish the first dedicated Kleefstra Syndrome Center of Excellence at Boston Children’s Hospital, so families can get expert care in one place instead of assembling it themselves.

Brings our community together. Conferences, events, and the connections families make there are not extras. They are how knowledge moves, how research recruits, and how no family faces this diagnosis alone.

Give before September 17 and your gift goes directly into research, care, and the community that carries all of it. Kleefstra syndrome is at a pivotal moment, and with your support, we can move faster toward the treatments our families have been waiting for.

What is Kleefstra Syndrome?

Kleefstra syndrome (KS) is a rare genetic neurodevelopmental disorder caused by a variant or deletion of the EHMT1 gene, which plays a critical role in brain development. KS can cause a wide range of features, including intellectual disability, speech delay, low muscle tone, seizures, and behavioral challenges, with severity ranging from mild to profound. KS is estimated to affect about 1 in 30,000 births — roughly 10,000 people in the U.S. and 250,000 worldwide.

IDefine, Inc. is a Georgia nonprofit corporation and a tax-exempt public charity under Section 501(c)(3) of the Internal Revenue Code (Federal Tax ID/EIN: 85-1404717). Contributions to IDefine are tax-deductible to the fullest extent of the law.