When to Worry About Rett Syndrome in a 2-Year-Old

If your bright, chatty toddler suddenly seems to be slipping backwards — losing words or hand skills she once had — your worry deserves a calm, clear answer.

In short

Rett Syndrome (ICD-11 LD90.0) is a rare genetic condition that affects girls far more often than boys. The single most important sign to act on is regression — a child who was developing typically begins to lose skills she already had, especially purposeful use of her hands and spoken words, usually between about 6 and 18 months. By age two, the key thing that warrants a prompt check is this loss of previously gained abilities, often alongside repetitive hand movements (wringing, washing or mouthing motions) and slowing head growth. These are reasons to seek assessment, not a diagnosis you can make at home.

What to watch for at this age

Most developmental conditions involve a child being slower to gain skills. Rett Syndrome is different — its hallmark is losing skills that were already there. By two years, signs that should prompt a clinical conversation include:

• Loss of purposeful hand use — she no longer reaches, grasps or points as she once did
• Repetitive hand movements — wringing, clapping, washing-like motions, or hand-to-mouth movements that replace useful hand skills
• Loss of spoken words or babble she previously used
• Slowing head growth (your paediatrician may note this on the growth chart)
• Problems with walking or balance, or a stiff, unsteady gait
• Withdrawal of social engagement that had previously been present

A single trait in isolation is rarely cause for alarm — many toddlers go through quiet phases or hand habits. It is the pattern of regression, the loss of established skills, that makes Rett different and worth checking promptly.

When to act

Because Rett Syndrome is genetic and confirmed by a specific gene test (most often MECP2), any clear regression — losing words, losing hand skills, or a noticeable slowing of head growth — is a reason to see your paediatrician without delay rather than waiting. Early identification opens the door to therapy that supports communication, movement and daily living. This is a medical pathway first: your doctor can arrange the right specialist referral and genetic testing.

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 form or a checklist. Once a medical diagnosis is in hand, our therapists build a warm, ability-first plan around your daughter — supporting communication through speech therapy, and hand use, posture and movement through occupational therapy. You can read more about the condition itself on our Rett Syndrome page.

Trusted sources

WHO ICD-11 (LD90.0, Rett Syndrome); American Academy of Pediatrics developmental-surveillance guidance (healthychildren.org); WHO Nurturing Care Framework for early childhood development.

Next step — If your daughter has lost words or hand skills she once had, see your paediatrician promptly, and book a developmental check with a Pinnacle clinician to plan supportive therapy.