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Gene Therapy Trial for Girls with Rett Syndrome: What Parents Need to Know About TSHA-102 (REVEAL Study)

A Phase 1/2/3 clinical trial is testing a one-time gene therapy called TSHA-102, delivered by spinal injection, in females ages 6 to under 22 with classic Rett syndrome.

Educational summary - not medical advice. Always consult your child's care team.
Rett SyndromeClinical Trials·

Research Profile

Source:ClinicalTrials.gov — Taysha Gene Therapies, Inc.

Published: March 6, 2023

Added to SpecialCircle: July 26, 2026

Evidence Level

Clinical trial

Research Status

Active clinical trial

Key takeaways

  • •TSHA-102 is a gene therapy designed to target the root genetic cause of Rett syndrome by regulating MECP2 expression in cells.
  • •The therapy is given as a single injection into the spinal canal (intrathecal), not an IV or pill.
  • •The trial has two parts: Part A (safety and dose-finding, now closed) enrolled 6 participants; Part B (Phase 3) enrolled females ages 6 to under 22 with a target of up to 15 participants.
  • •Participants are followed for 5 years after receiving the treatment to track safety and how well it works.
  • •The trial is active but no longer recruiting new participants as of the most recent update.

Source

ClinicalTrials.gov — Taysha Gene Therapies, Inc. · Clinical trial registry

Read the original source

Plain-language summary

Researchers are studying a gene therapy called TSHA-102, made by a company called Taysha Gene Therapies, to see if it is safe and helpful for girls with classic Rett syndrome. The therapy is given as a single injection into the fluid around the spinal cord.

The study has two parts — the first part (Part A) tested safety and helped identify the right dose, enrolling 6 participants, and the second part (Part B, Phase 3) is testing that dose in females ages 6 to under 22. Each participant in the study is watched closely for 5 years.

The trial is currently active but is no longer signing up new participants.

How it works

Science explained

Rett syndrome is caused by a mutation in the MECP2 gene that stops it from working properly. TSHA-102 uses a virus called AAV9 as a delivery vehicle to carry the therapy directly into the fluid around the spinal cord (this is called an intrathecal injection). Once inside, the therapy is designed to help cells regulate MECP2 expression. The goal is to target the genetic root cause of the condition rather than just managing symptoms. Because the trial's primary objective is to evaluate safety, researchers are still studying how the body responds to this approach.

Why parents may care

If you have a daughter with classic Rett syndrome caused by an MECP2 mutation, this trial is directly targeting the genetic root cause of the condition. While this trial is no longer recruiting, understanding how it works and what results emerge over the 5-year follow-up period could be very important for future treatment options for your child.

What this means for daily life

This trial does not yet tell us whether TSHA-102 will improve daily life for girls with Rett syndrome — that is what the study is trying to find out. Families who took part had to live near a study site for at least 3 months after treatment and commit to 5 years of follow-up visits.

Clinical trial journey

  1. Phase

    Phase 1/2/3 (Part A: Phase 1/2 — closed; Part B: Phase 3 — active)

  2. Enrollment

    Active but not recruiting — Part A (6 participants) is complete; Part B targeting 15 participants

  3. Data collection

    Each participant is followed for 5 years after receiving TSHA-102 to assess safety and efficacy

  4. Preliminary results

    Part A (dose-finding phase) is complete and identified Dose Level 2 as the dose to use in Phase 3; detailed results are not reported on this registry page

  5. Regulatory / next steps

    Phase 3 (Part B) is ongoing with up to 15 females ages 6 to under 22; results will be analyzed after the 5-year follow-up period

Who may be eligible

Females ages 6 to under 22 with a clinical diagnosis of classic/typical Rett syndrome and a confirmed MECP2 loss-of-function mutation; must not require invasive breathing support; must be able to live near the study site for at least 3 months post-treatment

Find a trial site near you

What is still unknown

We do not yet know whether TSHA-102 is effective, what the full range of side effects may be, or how long any benefits might last. Long-term results from the 5-year follow-up period have not yet been reported.

It is also unknown whether this therapy could work for atypical Rett syndrome or MECP2 mutations that do not cause classic Rett syndrome, as those individuals were excluded from this trial.

Frequently asked questions about Rett Syndrome

TSHA-102 is a gene therapy being tested in the REVEAL study for females ages 6–21 with classic Rett syndrome. It is given as a single injection into the spinal canal and is designed to address the faulty MECP2 gene that causes Rett syndrome.

Terminology glossary

MECP2 gene
A gene that provides instructions for making a protein the brain needs to function; mutations in this gene that cause it to stop working are the root cause of classic Rett syndrome.
Intrathecal injection
A way of delivering medicine directly into the fluid that surrounds the brain and spinal cord, allowing it to reach the nervous system more effectively.
AAV9
A harmless, naturally occurring virus that scientists have adapted to act as a delivery vehicle, carrying a working gene into a patient's cells.
Gene therapy
A medical approach that tries to treat or prevent disease by delivering a working copy of a faulty gene into the body's cells.
Open-label study
A type of clinical trial where both the researchers and the participants know what treatment is being given, as opposed to a blinded study where this information is hidden.
Dose escalation
A process in clinical trials where researchers start with a lower dose of a treatment and gradually increase it to find the safest and most effective amount.

Questions to ask your doctor or therapist

  • ?Is my daughter a candidate for gene therapy trials like TSHA-102 based on her specific MECP2 mutation?
  • ?Are there other gene therapy or clinical trials for Rett syndrome that are currently recruiting?
  • ?What would the follow-up schedule look like if my daughter participated in a study like this?
  • ?How will we know if a gene therapy is working, and what outcomes are doctors measuring?

⚕️ This research digest is for educational and community support purposes only. It is not medical advice, diagnosis, or treatment. Always speak with a qualified doctor, therapist, or medical professional before making decisions about care.

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