IDefine and UT Southwestern Announce Research Collaboration to Advance Gene Therapy for Rare Disease Kleefstra Syndrome

-  Dr. Steven Gray will lead research effort focused on potential therapy to replace the EHMT1 gene in patients with rare neurodevelopmental disorder

ATLANTA, June 3, 2026 /PRNewswire/ -- IDefine – The Kleefstra Syndrome Foundation, a leading patient advocacy organization, today announced a collaboration with UT Southwestern Medical Center to advance development of a potential gene therapy to treat Kleefstra syndrome (KS), a rare neurodevelopmental disorder caused by changes or loss of the EHMT1 gene, which plays a critical role in brain development and function.

The two-year research program, led by Steven Gray, PhD, professor at UT Southwestern and director of the UTSW Gene Therapy Program, will evaluate the feasibility and safety of EHMT1 gene replacement therapy using next-generation gene delivery technology designed to target the central nervous system (CNS).

"This landmark research collaboration represents a meaningful step forward in our mission to accelerate research that can lead to a first treatment for Kleefstra syndrome," said Eric Scheeff, PhD, chief scientific officer of IDefine. "We are especially honored to support and partner with Dr. Steven Gray and the UT Southwestern Gene Therapy Program in this effort. Their expertise and dedication give us the very best chance to identify an eventual treatment that can make a meaningful difference for patients and families."

KS presents with a wide range of symptoms, including intellectual disability, speech impairment, low muscle tone, seizures, and behavioral challenges, with severity ranging from mild to profound. There are currently no approved treatments for the disease.

"Advances in gene therapy and CNS-targeted delivery technologies are creating new opportunities to develop potential treatments for complex neurodevelopmental disorders like Kleefstra syndrome," said Dr. Gray. "Through this collaboration, we aim to evaluate a carefully designed EHMT1 gene replacement approach while prioritizing safety and appropriate regulation of gene expression. We are grateful to partner with IDefine in support of this important research."

Under the agreement, IDefine will provide approximately $310,000 in funding to support the pre-clinical research program, expected to continue through April 2028.

About IDefine

IDefine is the leading nonprofit patient advocacy organization dedicated to supporting individuals and families impacted by Kleefstra syndrome and accelerating the development of treatments and a cure. Founded in 2020 by parents of children diagnosed with the condition, IDefine brings urgency, determination, and a deeply personal commitment to advancing research and improving outcomes. The organization funds and drives critical research, builds collaborative partnerships with clinicians, researchers, and industry, and fosters a strong, connected community so no family faces Kleefstra syndrome alone. Through its efforts, IDefine is helping to advance scientific understanding and move the field closer to meaningful therapies and, ultimately, a cure. For more information, visit https://www.idefine.org/.

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SOURCE IDefine - The Kleefstra Syndrome Foundation