Rett Syndrome
Screening and diagnostic pathway for Rett syndrome under 7
Rett syndrome (ICD-11 LD90.0) is diagnosed clinically using consensus criteria and confirmed by MECP2 (plus CDKL5/FOXG1 for variants) testing. There is no population screen, so developmental surveillance for the regression-and-hand-stereotypy phenotype drives referral, alongside EEG, ECG and scoliosis review.
A girl with normal early months who then plateaus, loses purposeful hand use, and develops hand stereotypies — the pattern that should prompt structured pursuit of Rett syndrome.
In short
Rett syndrome (ICD-11 LD90.0) is a clinical diagnosis confirmed by molecular testing. In a child under 7, the pathway is: recognise the regression-and-stereotypy phenotype, apply the consensus diagnostic criteria, and confirm with MECP2 sequencing and deletion/duplication analysis. Screening is surveillance-based — there is no population newborn screen — so vigilance at routine developmental reviews drives early referral.The pathway, step by step
1. Surveillance and red flags. Suspect classic Rett in a girl with a period of relatively normal development (often to 6–18 months) followed by developmental stagnation, then regression — loss of acquired purposeful hand skills, loss of spoken language, gait/truncal apraxia, and emergence of stereotypic midline hand movements (wringing, washing, mouthing).2. Apply consensus criteria. Use the revised diagnostic criteria (Neul et al.) distinguishing classic (all four main criteria, after a regression-then-recovery/stabilisation period) from atypical variants. Exclusion criteria — e.g. acquired brain injury, storage disease — must be reviewed.
3. Molecular confirmation. Refer for MECP2 testing (sequencing plus MLPA for large deletions/duplications). For atypical phenotypes consider CDKL5 (early-seizure variant) and FOXG1 (congenital variant). Genetic counselling accompanies testing.
4. Co-morbidity screen. Baseline EEG (seizures are common), ECG for QT prolongation, growth/feeding, scoliosis and breathing-pattern review.
A negative gene result does not exclude a clinically definite diagnosis — the criteria remain clinical.
The Pinnacle way
A clinical AbilityScore® and any diagnosis are formed only at a Pinnacle Blooms Network centre, under qualified clinician care — our clinician-administered structured assessment complements, and never replaces, genetic confirmation. We co-manage the functional roadmap — hand function, communication and mobility — through occupational therapy and integrated Rett syndrome support across 70+ centres.Trusted sources
WHO ICD-11 (LD90.0); consensus revised diagnostic criteria for Rett syndrome; AAP developmental surveillance guidance.Next step — Refer a suspected case for co-ordinated genetic and functional work-up: partner with a Pinnacle centre.
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.
What to watch
Developmental stagnation then regression in a girl 6–18 months old, loss of purposeful hand use, midline hand stereotypies, deceleration of head growth, and emerging gait apraxia.
Try this at home
Document the timeline of skill loss precisely — the regression window and sequence are central to applying the consensus criteria and prioritising MECP2 testing.
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 there a newborn screening test for Rett syndrome?
No. There is no population-level newborn screen for Rett syndrome. Detection relies on developmental surveillance — recognising the characteristic stagnation, regression and hand stereotypies — followed by criteria-based clinical diagnosis and MECP2 molecular confirmation.
Does a negative MECP2 result rule out Rett syndrome?
No. Rett syndrome remains a clinical diagnosis based on consensus criteria. A negative MECP2 result does not exclude clinically definite Rett; consider CDKL5 (early-seizure variant) and FOXG1 (congenital variant) testing and review atypical phenotypes.
What co-morbidities should be screened at diagnosis?
Baseline EEG for seizure activity, ECG to assess for QT prolongation, growth and feeding review, scoliosis monitoring, and assessment of disordered breathing patterns are appropriate at diagnosis and on ongoing follow-up.