Rett Syndrome Study Hints at Personalized Therapies

MIT neuroscientists find two different MECP2 mutations have distinct effects on brain organoid structure and function

Apr. 15, 2026 at 5:18am

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A highly textured, abstract painting in earthy tones of green, blue, and brown, featuring sweeping geometric arcs, concentric circles, and precise botanical spirals, conceptually representing the complex genetic and cellular mechanisms underlying the distinct effects of different MECP2 mutations in Rett syndrome.A conceptual illustration of the divergent molecular pathways and neural network disruptions caused by specific MECP2 mutations in Rett syndrome, hinting at the need for personalized therapies.Boston Today

A new study by neuroscientists at MIT's Picower Institute for Learning and Memory shows that two different mutations of the MECP2 gene, which can cause the developmental disorder Rett syndrome, led to many distinct abnormalities in lab-grown brain tissue cultures called organoids. The findings suggest that personalized treatments may be needed even for single-gene disorders like Rett syndrome.

Why it matters

Rett syndrome is a rare but devastating neurological disorder that primarily affects girls. While many studies have approached it as a single condition caused by general loss of function in the MECP2 gene, this research indicates the importance of understanding how specific mutations of that gene can lead to divergent effects on brain development and function. Developing personalized therapies based on a patient's unique genetic profile could significantly improve treatment outcomes.

The details

The study employed advanced 3D human brain tissue cultures called "organoids" or "minibrains" derived from skin cells or blood cells donated by Rett syndrome patients with two different MECP2 mutations. The researchers found that the R306C and V247X mutations, which account for a significant portion of Rett syndrome cases, produced some common effects on the organoids' structure, neural activity, and connectivity, but also distinct differences. For example, the V247X organoids were larger and had different layer thicknesses compared to controls, while the R306C ones were more similar. Both showed reduced neuron firing and synchronicity, but diverged in a measure of network efficiency. The team also identified specific gene expression changes and molecular pathway disruptions underlying the mutation-specific effects, and were able to partially restore normal function by treating the organoids with existing drugs that target those pathways.

  • The study was published on April 15, 2026.

The players

Mriganka Sur

Senior author of the study, Newton Professor at The Picower Institute and the Department of Brain and Cognitive Sciences at MIT.

Tatsuya Osaki

Lead author of the study, a Picower Institute research scientist.

Charles Nelson

Researcher at Boston Children's Hospital who collaborated with the MIT team to measure EEG in Rett syndrome patients.

The Picower Institute for Learning and Memory

A research institute at MIT where the study was conducted.

MIT

Massachusetts Institute of Technology, where the study was carried out.

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What they’re saying

“Individual mutations matter. This is an approach to personalizing treatment, even for a single-gene disorder.”

— Mriganka Sur, Senior author, Newton Professor

“The organoids' ability to model the specific consequences of each mutation enabled me to gain mutation-specific insights that haven't emerged in prior studies where scientists have just knocked out MECP2 overall.”

— Tatsuya Osaki, Lead author, research scientist

What’s next

The researchers plan to apply their organoid platform to studying four more MECP2 mutations, comparing them all against a standardized control organoid, in order to further develop personalized treatment approaches for Rett syndrome.

The takeaway

This study demonstrates the importance of understanding how specific genetic mutations can lead to divergent effects in single-gene disorders like Rett syndrome. By using advanced brain organoid models, the researchers were able to identify mutation-specific disruptions in brain development and function, paving the way for more personalized therapeutic strategies.