Do girls show Rett Syndrome differently?

If you have a daughter and the word "Rett" has entered your world, you are likely searching for what this looks like in girls specifically — let's walk through it gently and clearly.

In short

Rett Syndrome is recognised classically in girls, and there's a biological reason for that: it's linked to a gene on the X chromosome. Girls typically develop in a way that looks ordinary for the first 6–18 months, then go through a period where earlier skills — like purposeful hand use and babble — slow or fade, and characteristic hand movements appear. Boys are affected far less often and usually quite differently and more severely, which is why most of what we describe applies to girls. None of this is a diagnosis you can make at home — but knowing the pattern helps you ask the right questions.

What this tends to look like in girls

Because girls have two X chromosomes, the typical Rett picture (ICD-11 LD90.0) tends to unfold in recognisable stages rather than all at once:

• Early months — development often appears typical, which is why early signs are easy to miss
• 6–18 months — a plateau or gentle loss of skills already gained: less babbling, reduced eye engagement, slowing head growth
• Loss of purposeful hand use — replaced by repetitive hand movements such as wringing, washing, mouthing or clapping motions
• Movement and walking changes — unsteady gait, or difficulty starting to walk
• Communication shifts — many girls retain warm, expressive eye gaze even when spoken words are limited, and this becomes a powerful channel for connection

Every girl's path is her own. Some are mildly affected; others need more support. The reassuring thread is that intervention — communication, motor, sensory — meets her where she is.

When to seek advice promptly

If your daughter is losing skills she once had — words, babble, or the ability to use her hands purposefully — or her head growth seems to be slowing, please arrange a developmental review without delay. Loss of established skills always deserves prompt clinical attention, whatever the eventual explanation.

The Pinnacle way

A clinical AbilityScore® and any diagnosis are formed only at a Pinnacle Blooms Network centre, under the care of a qualified clinician — never from an online description or form. Our approach builds on a girl's strengths, especially eye-gaze communication and motor support, through occupational therapy and a coordinated plan tailored to her. Begin here at our [developmental support home](/) to understand the next steps.

Trusted sources

World Health Organization ICD-11 (LD90.0); American Academy of Pediatrics guidance on developmental surveillance; ASHA resources on communication in complex developmental conditions.

Next step — If you've noticed a loss of skills or the hand movements described here, book a developmental assessment with a Pinnacle clinician — early clarity opens the door to early support.

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.