# Types and Stages of Rett Syndrome

Canonical: https://pinnacleblooms.org/ask/what-are-the-types-or-levels-of-rett-syndrome
Publisher: Pinnacle Blooms Network / Bharath Healthcare Laboratories Private Limited

Rett syndrome isn't graded mild-to-severe. Clinicians describe it by four developmental stages (early onset, rapid regression, plateau, late motor decline) and by type — classic (typical) Rett syndrome and several atypical (variant) forms. A diagnosis is confirmed only by a clinician, with genetic testing.

*When a family first hears "Rett syndrome", one of the earliest questions is whether there are different kinds — and the answer brings real clarity and hope.*

## In short
Rett syndrome isn't sorted into "mild to severe" grades — instead, clinicians describe it in two helpful ways. First, by **stage**: it tends to move through four recognisable phases as a child grows. Second, by **type**: there is **classic (typical) Rett syndrome**, which follows the well-known pattern, and several **atypical (variant) forms** that look a little different. Knowing which picture fits your child guides the right support — and every child's journey is wonderfully individual.

## The four stages
Most children with classic Rett syndrome move through four broad stages, though the timing and intensity vary from child to child:

- **Stage 1 — Early onset (around 6–18 months):** development slows or plateaus; eye contact and play may become less frequent.
- **Stage 2 — Rapid regression (around 1–4 years):** previously gained skills, especially purposeful hand use and spoken words, may fade; characteristic hand movements (wringing, mouthing) often appear.
- **Stage 3 — Plateau (preschool to school years):** things often steady; communication, alertness and social engagement can improve — a meaningful window for therapy.
- **Stage 4 — Late motor decline (school age onward):** mobility may reduce, though cognition and connection often remain stable.

## Classic versus atypical types
**Classic (typical) Rett syndrome** follows the recognised pattern above and is most often linked to changes in the *MECP2* gene. **Atypical (variant) forms** differ in onset or features and include recognised variants such as the early-seizure type, the congenital type, and the preserved-speech (Zappella) variant, where some language is retained. A clinician confirms the picture through developmental assessment alongside genetic testing — never from signs alone.

## The Pinnacle way
A clinical AbilityScore® and any diagnosis are formed only at a Pinnacle Blooms Network centre, under qualified clinician care — never from an online list. Understanding your child's stage and profile lets us shape support that truly fits, through [coordinated therapy](/occupational-therapy) and a clear [understanding of where your child stands today](/ask/what-is-the-abilityscore-and-how-is-it-calculated). Learn more about [Rett syndrome and our approach](/rett-syndrome).

## Trusted sources
World Health Organization ICD-11; American Academy of Pediatrics (healthychildren.org); WHO maternal and child health guidance — all paraphrased for clarity.

**Next step —** Curious where your child stands right now? [A Pinnacle clinician can help you find out](/rett-syndrome).

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

## Sources
- WHO ICD-11: https://icd.who.int
- AAP HealthyChildren — developmental milestones: https://www.healthychildren.org
- WHO — child health and development: 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
- Screen: https://pinnacleblooms.org/ask/lens/lifecycle/screen
- Book Assessment: https://pinnacleblooms.org/ask/lens/route/book-assessment
- Early Clarity: https://pinnacleblooms.org/ask/lens/empowerment/early_clarity

## Related question paths

### Understand the subject
- 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
- What causes Rett syndrome in children?: https://pinnacleblooms.org/ask/what-causes-rett-syndrome-in-children
- What is Rett Syndrome?: https://pinnacleblooms.org/ask/what-is-rett-syndrome
- What is Rett Syndrome, and what does it look like in early childhood?: https://pinnacleblooms.org/ask/what-is-rett-syndrome-and-what-does-it-look-like-in-early-childhood
- 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
- 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: https://pinnacleblooms.org/ask/what-are-the-early-signs-of-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
- Early signs of Rett Syndrome in a 2-year-old boy: https://pinnacleblooms.org/ask/what-are-the-early-signs-of-rett-syndrome-in-a-2-year-old-boy

### Explore causes & influences
- 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 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
- 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
- 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
- Does Rett Syndrome Get Better or Worse?: https://pinnacleblooms.org/ask/does-rett-syndrome-get-better-or-worse-as-a-child-grows
- How Does Rett Syndrome Change as a Child Grows Older?: https://pinnacleblooms.org/ask/how-does-rett-syndrome-change-as-a-child-grows-older
- How is Rett Syndrome diagnosed in a child?: https://pinnacleblooms.org/ask/how-is-rett-syndrome-diagnosed-in-a-child
- What to expect as your child with Rett syndrome grows up: https://pinnacleblooms.org/ask/what-can-i-expect-as-my-child-with-rett-syndrome-grows-up
- 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

### 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