Rett Syndrome
Should I be worried my child might have Rett Syndrome?
Worry is reasonable, but worry is not a diagnosis. Rett Syndrome (ICD-11 LD90.0) is rare and marked by a loss of skills after a normal start — most commonly loss of hand use and language between 6–18 months. A clear regression deserves prompt review; genetic testing and a clinician confirm it.
When your daughter's development takes an unexpected turn, the worry can be overwhelming — let's bring some calm clarity to what you're seeing.
In short
Rett Syndrome is a rare genetic condition (WHO ICD-11 LD90.0), affecting almost exclusively girls. Its hallmark is a regression — a child who developed typically in early infancy begins, usually between 6 and 18 months, to lose skills she had gained. Worry is reasonable, but worry is not a diagnosis. Most children who develop a little differently do not have Rett Syndrome, and only genetic testing and a qualified clinician can confirm or rule it out.Signs worth attention
The pattern that matters is loss after a normal start, not slowness alone. Watch for:- Loss of purposeful hand use — and the appearance of repetitive hand movements such as wringing, washing or mouthing
- Loss of spoken words or babble she previously had
- Slowing head growth noted on growth charts
- Changes in walking — unsteady, stiff or on tiptoes
- Loss of social engagement during the regression phase
A single delayed milestone is common and often resolves. A clear regression — going backwards — is the real flag and deserves prompt review.
The science, briefly
Most classic Rett Syndrome is linked to changes in the MECP2 gene, confirmed by a genetic test your paediatrician can arrange. Because Rett is rare and other, more common reasons for delay exist, the right first step is a careful developmental check — not panic. Early support meaningfully helps movement, communication and daily comfort.The Pinnacle way
No diagnosis — and no clinical AbilityScore® — is ever made from an online form; both are formed only at a Pinnacle Blooms Network centre under a qualified clinician's care, who will look for other causes first and guide any genetic referral. Where support is needed, our therapy programmes build on your child's own strengths. The aim is always comfort, connection and capability.Trusted sources
WHO ICD-11 (LD90.0); American Academy of Pediatrics and HealthyChildren.org guidance on developmental regression; ASHA on communication support.Next step — The kindest thing to do with worry is to check. Book a developmental assessment with a Pinnacle clinician.
What to watch
Seek a prompt check if your child loses skills she once had — purposeful hand use, words or babble — develops repetitive hand wringing or washing movements, shows slowing head growth, or becomes less socially engaged after a period of typical development.
Try this at home
Keep a simple month-by-month note or short videos of skills your child has gained — words, gestures, hand use. If something she could do clearly disappears, that record gives your clinician the clearest, calmest picture to work from.
Trusted sources
Developed by SETU Consortium · Pinnacle Blooms Network · Last reviewed 2026-06-10
This is general information, not a diagnosis. A clinical AbilityScore® and any diagnosis are formed only at a Pinnacle Blooms Network centre, under qualified clinician care.
Frequently asked
Is Rett Syndrome common?
No. Rett Syndrome is rare and occurs almost exclusively in girls. Most children who develop a little differently do not have it. A careful developmental check helps tell the difference calmly.
What is the single most important sign?
Regression — losing skills your child once had, rather than simply being slow to gain new ones. Loss of purposeful hand use with new repetitive hand movements, usually between 6 and 18 months, is the classic flag.
How is Rett Syndrome confirmed?
Through a genetic test, most often looking at the MECP2 gene, arranged by your paediatrician, alongside clinical assessment. It is never confirmed from an online checklist or form.
Can therapy help my child?
Yes. Whatever the final picture, early, strengths-based support for movement, communication and daily comfort can meaningfully improve quality of life. The first step is a clinician-led assessment.