# What is Rett Syndrome, and what does it look like in early childhood?

Canonical: https://pinnacleblooms.org/ask/what-is-rett-syndrome-and-what-does-it-look-like-in-early-childhood
Publisher: Pinnacle Blooms Network / Bharath Healthcare Laboratories Private Limited

Rett Syndrome (ICD-11 LD90.0) is a rare neurodevelopmental condition affecting mostly girls, usually caused by a MECP2 gene change. After typically normal early development, skills slow and are lost — especially purposeful hand use and spoken language, with characteristic repetitive hand movements. Diagnosis is clinical and genetic, formed only at a Pinnacle centre.

*When a baby girl develops beautifully for a few months and then her hands seem to lose their purpose, that change has a name — and an explanation.*

## In short
Rett Syndrome is a rare neurodevelopmental condition, recognised under ICD-11 as **LD90.0**, that affects mostly girls and is usually caused by a change in the *MECP2* gene. Its hallmark is a period of early development that appears typical, followed by a slowing and then a loss of skills already gained — particularly purposeful use of the hands and spoken language. It is identified by clinicians, not by parents, and early recognition opens the door to supportive therapy and genetic confirmation.

## What it can look like in early childhood
Most babies with Rett Syndrome grow and develop as expected for the first 6–18 months. Then a recognisable pattern may emerge:

- A **slowing of head growth** in the first two years
- **Loss of purposeful hand skills** that were already there — reaching, grasping, holding
- **Repetitive hand movements** such as wringing, washing, clapping or mouthing
- **Loss of spoken words or babble** and reduced social engagement, which may later partly return
- **Walking that becomes unsteady**, or difficulty starting to walk
- Changes in breathing patterns when awake, and reduced eye-pointing or gaze communication

Because this involves a *loss* of previously gained skills, any regression at any age deserves prompt medical attention — not a wait-and-watch approach.

## The Pinnacle way
Developmental measurement supports care planning; diagnosis requires an appropriately qualified healthcare professional., under qualified clinician care — genetic testing and paediatric neurology confirm Rett Syndrome itself. From there, your child's [strengths and support needs are mapped](/ask/what-is-the-abilityscore-and-how-is-it-calculated), and [occupational therapy](https://www.pinnacleblooms.org/best-occupational-therapy-center-india-proven-improvement-rate) helps protect and rebuild everyday hand and self-care skills. Learn more about [Rett Syndrome](/rett-syndrome) and how families are supported.

## Trusted sources
WHO ICD-11 classification of Rett Syndrome; American Academy of Pediatrics guidance on developmental regression; ICF framework for functioning and support.

**Next step —** If your child has lost skills she once had, [speak with a Pinnacle clinician](https://www.pinnacleblooms.org/best-occupational-therapy-center-india-proven-improvement-rate) without delay.

This is general information, not a diagnosis — individual assessment and diagnosis require an appropriately qualified healthcare professional.

## Sources
- WHO ICD-11: Rett Syndrome (LD90.0): https://icd.who.int/
- AAP HealthyChildren: developmental concerns and regression: https://www.healthychildren.org/
- WHO ICF framework for functioning and support: https://www.who.int/

## Connected topics and perspectives
- Conditions: https://pinnacleblooms.org/ask/conditions
- Parent: https://pinnacleblooms.org/ask/lens/stakeholder/parent
- Context: https://pinnacleblooms.org/ask/lens/domain/context
- Definition: https://pinnacleblooms.org/ask/lens/intent/definition
- Act: https://pinnacleblooms.org/ask/lens/lifecycle/act
- Screen: https://pinnacleblooms.org/ask/lens/route/screen
- Early Clarity: https://pinnacleblooms.org/ask/lens/empowerment/early_clarity

## Related question paths

### Understand the subject
- What is Rett Syndrome?: https://pinnacleblooms.org/ask/what-is-rett-syndrome
- How Rett Syndrome Affects a Child's Daily Life: https://pinnacleblooms.org/ask/how-does-rett-syndrome-affect-a-child-s-daily-life
- Is Rett Syndrome considered a disability?: https://pinnacleblooms.org/ask/is-rett-syndrome-considered-a-disability
- Is Rett Syndrome Genetic or Hereditary?: https://pinnacleblooms.org/ask/is-rett-syndrome-genetic-or-hereditary
- What are common myths about Rett Syndrome?: https://pinnacleblooms.org/ask/what-are-common-myths-about-rett-syndrome
- Types and Stages of Rett Syndrome: https://pinnacleblooms.org/ask/what-are-the-types-or-levels-of-rett-syndrome
- What causes Rett syndrome in children?: https://pinnacleblooms.org/ask/what-causes-rett-syndrome-in-children
- Conditions That Occur Alongside Rett Syndrome: https://pinnacleblooms.org/ask/what-other-conditions-often-occur-alongside-rett-syndrome
- Early Intervention Outcomes in Rett Syndrome (Under 7): https://pinnacleblooms.org/ask/what-does-current-research-show-about-early-intervention-outcomes-for-rett-syndrome-in-children-under-7
- What is Rett Syndrome, and its ICD-11 features in early childhood?: https://pinnacleblooms.org/ask/what-is-rett-syndrome-and-what-are-its-icd-11-features-in-early-childhood
- ICD-11 Classification of Rett Syndrome (LD90.0): https://pinnacleblooms.org/ask/what-is-the-icd-11-classification-for-rett-syndrome
- What is the SNOMED CT concept for Rett Syndrome?: https://pinnacleblooms.org/ask/what-is-the-snomed-ct-concept-for-rett-syndrome

### Recognise signs & concerns
- Early Signs of Rett Syndrome: https://pinnacleblooms.org/ask/what-are-the-early-signs-of-rett-syndrome
- Early Signs of Rett Syndrome in a 6-Year-Old: https://pinnacleblooms.org/ask/what-are-the-early-signs-of-rett-syndrome-in-a-6-year-old
- Can Rett Syndrome Be Cured?: https://pinnacleblooms.org/ask/can-rett-syndrome-be-cured
- Can Rett Syndrome Be Prevented?: https://pinnacleblooms.org/ask/can-rett-syndrome-be-prevented
- Rett Syndrome in Boys: https://pinnacleblooms.org/ask/do-boys-show-rett-syndrome-differently
- Do girls show Rett Syndrome differently?: https://pinnacleblooms.org/ask/do-girls-show-rett-syndrome-differently
- Should I be worried my child might have Rett Syndrome?: https://pinnacleblooms.org/ask/should-i-be-worried-my-child-might-have-rett-syndrome
- Early signs of Rett syndrome in a 1-year-old boy: https://pinnacleblooms.org/ask/what-are-the-early-signs-of-rett-syndrome-in-a-1-year-old-boy
- Early Signs of Rett Syndrome in a 1-Year-Old Girl: https://pinnacleblooms.org/ask/what-are-the-early-signs-of-rett-syndrome-in-a-1-year-old-girl
- Early Signs of Rett Syndrome at 12–18 Months: https://pinnacleblooms.org/ask/what-are-the-early-signs-of-rett-syndrome-in-a-12-to-18-month-old
- Early Signs of Rett Syndrome in an 18-to-24-Month-Old: https://pinnacleblooms.org/ask/what-are-the-early-signs-of-rett-syndrome-in-a-18-to-24-month-old
- Early Signs of Rett Syndrome in a 2-Year-Old: https://pinnacleblooms.org/ask/what-are-the-early-signs-of-rett-syndrome-in-a-2-year-old

### Explore causes & influences
- How Rett Syndrome Affects Motor Development: https://pinnacleblooms.org/ask/how-does-rett-syndrome-affect-a-child-s-motor-development
- Are boys more likely to have Rett Syndrome?: https://pinnacleblooms.org/ask/are-boys-more-likely-to-have-rett-syndrome
- Are girls more likely to have Rett Syndrome?: https://pinnacleblooms.org/ask/are-girls-more-likely-to-have-rett-syndrome
- What Causes Rett Syndrome in Young Children?: https://pinnacleblooms.org/ask/what-causes-rett-syndrome-in-young-children
- Early Intervention for Rett Syndrome, UNCRPD & the SDGs: https://pinnacleblooms.org/ask/how-does-early-intervention-for-rett-syndrome-advance-un-child-rights-uncrpd-and-the-sdgs
- Known contributing factors for Rett Syndrome: https://pinnacleblooms.org/ask/what-are-the-known-contributing-factors-for-rett-syndrome-in-early-childhood
- Cost-effectiveness of early therapy for Rett Syndrome in young children: https://pinnacleblooms.org/ask/what-is-the-cost-effectiveness-of-early-therapy-for-rett-syndrome-in-young-children
- Prevalence and Public-Health Burden of Rett Syndrome in India: https://pinnacleblooms.org/ask/what-is-the-prevalence-and-public-health-burden-of-rett-syndrome-among-young-children-in-india

### Understand assessment
- How AbilityScore Tracks Progress in a Child with Rett Syndrome: https://pinnacleblooms.org/ask/how-does-abilityscore-track-progress-in-a-child-with-rett-syndrome
- How Rett Syndrome Is Assessed in a Young Child: https://pinnacleblooms.org/ask/how-is-rett-syndrome-assessed-in-a-young-child
- How Rett Syndrome Is Assessed in Children Under 7: https://pinnacleblooms.org/ask/how-is-rett-syndrome-assessed-in-children-under-7
- What an AbilityScore® of 0–100 means for a child with Rett Syndrome: https://pinnacleblooms.org/ask/what-does-an-abilityscore-of-0-100-mean-for-a-child-with-rett-syndrome
- What does an AbilityScore of 100–200 mean for a child with Rett Syndrome?: https://pinnacleblooms.org/ask/what-does-an-abilityscore-of-100-200-mean-for-a-child-with-rett-syndrome
- What does an AbilityScore of 200–300 mean for a child with Rett Syndrome?: https://pinnacleblooms.org/ask/what-does-an-abilityscore-of-200-300-mean-for-a-child-with-rett-syndrome
- AbilityScore 300–400 in Rett Syndrome: https://pinnacleblooms.org/ask/what-does-an-abilityscore-of-300-400-mean-for-a-child-with-rett-syndrome
- What an AbilityScore of 400–500 Means in Rett Syndrome: https://pinnacleblooms.org/ask/what-does-an-abilityscore-of-400-500-mean-for-a-child-with-rett-syndrome
- What does an AbilityScore of 500–600 mean for a child with Rett Syndrome?: https://pinnacleblooms.org/ask/what-does-an-abilityscore-of-500-600-mean-for-a-child-with-rett-syndrome
- What does an AbilityScore of 600–700 mean for a child with Rett Syndrome?: https://pinnacleblooms.org/ask/what-does-an-abilityscore-of-600-700-mean-for-a-child-with-rett-syndrome
- What an AbilityScore of 700–800 Means for a Child with Rett Syndrome: https://pinnacleblooms.org/ask/what-does-an-abilityscore-of-700-800-mean-for-a-child-with-rett-syndrome
- What an AbilityScore of 800–900 Means for a Child with Rett Syndrome: https://pinnacleblooms.org/ask/what-does-an-abilityscore-of-800-900-mean-for-a-child-with-rett-syndrome

### Explore therapy & support
- How is Rett Syndrome diagnosed in a child?: https://pinnacleblooms.org/ask/how-is-rett-syndrome-diagnosed-in-a-child
- How Common Is Rett Syndrome in Children?: https://pinnacleblooms.org/ask/how-common-is-rett-syndrome-in-children
- Can a Child with Rett Syndrome Attend a Mainstream School?: https://pinnacleblooms.org/ask/can-a-child-with-rett-syndrome-attend-a-mainstream-school
- Can a Child with Rett Syndrome Attend a Regular School?: https://pinnacleblooms.org/ask/can-a-child-with-rett-syndrome-attend-a-regular-school
- Can a Child with Rett Syndrome Live Independently?: https://pinnacleblooms.org/ask/can-a-child-with-rett-syndrome-grow-up-to-live-independently
- How is Rett Syndrome supported through therapy?: https://pinnacleblooms.org/ask/how-is-rett-syndrome-supported-through-therapy
- Rett Syndrome AbilityScore®: What to Do Next: https://pinnacleblooms.org/ask/my-child-with-rett-syndrome-has-an-abilityscore-of-0-100-what-should-we-do-next
- Rett Syndrome with an AbilityScore of 100–200: your next step: https://pinnacleblooms.org/ask/my-child-with-rett-syndrome-has-an-abilityscore-of-100-200-what-should-we-do-next
- Rett Syndrome: AbilityScore 200–300 — what to do next: https://pinnacleblooms.org/ask/my-child-with-rett-syndrome-has-an-abilityscore-of-200-300-what-should-we-do-next
- Rett Syndrome: AbilityScore 300–400 — what to do next: https://pinnacleblooms.org/ask/my-child-with-rett-syndrome-has-an-abilityscore-of-300-400-what-should-we-do-next
- Rett Syndrome with an AbilityScore of 400–500: what to do next: https://pinnacleblooms.org/ask/my-child-with-rett-syndrome-has-an-abilityscore-of-400-500-what-should-we-do-next
- Rett Syndrome and an AbilityScore of 500–600: What To Do Next: https://pinnacleblooms.org/ask/my-child-with-rett-syndrome-has-an-abilityscore-of-500-600-what-should-we-do-next

### At home & in everyday life
- How can I support my child with Rett Syndrome at home?: https://pinnacleblooms.org/ask/how-can-i-support-my-child-with-rett-syndrome-at-home