Atypical Rett syndrome

What it is

From: Orphanet

A rare genetic neurological disorder characterized by the presence of two or more of the main criteria for classic Rett syndrome (loss of acquired purposeful hand skills, loss of acquired spoken language, gait abnormalities, stereotypic hand movements), a period of regression followed by recovery or stabilization, and five out of eleven supportive criteria (breathing difficulties, bruxism, impaired sleep pattern, abnormal muscle tone, peripheral vasomotor disturbances, scoliosis/kyphosis, delayed growth, small cold hands and feet, inappropriate laughter or screaming spells, decreased pain sensation, and intense eye communication). Like classic Rett syndrome, it almost exclusively affects girls, while the disease course may be either milder or more severe.

Reported clinical features and what the terms mean

The following findings are associated with this condition in Orphanet. They are not a checklist for diagnosing yourself, and they do not all occur in every affected person. Some are examination, imaging or laboratory findings that cannot be recognised at home.

The frequency labels describe how often a finding was reported among people with the condition in the source. They do not give the chance that a person with that symptom has the condition. Definitions below reproduce HPO terminology; they explain the term, not the likely severity in an individual.

Abnormal pattern of respiration · Very frequent (99-80%)

An anomaly of the rhythm or depth of breathing.

Abnormality of movement · Very frequent (99-80%)

An abnormality of movement with a neurological basis characterized by changes in coordination and speed of voluntary movements.

Agitation · Very frequent (99-80%)

A state of excessive motor activity that is associated with mental distress or a feeling of substantial unease or inner tension. Distinguished from restlessness by the increased level of emotional distress and negative intensity of the experience. Agitation has a significant level of physical activity that is typically threatening to the self or others.

Autistic behavior · Very frequent (99-80%)

Persistent deficits in social interaction and communication and interaction as well as a markedly restricted repertoire of activity and interest as well as repetitive patterns of behavior.

Developmental regression · Very frequent (99-80%)

Loss of developmental skills, as manifested by loss of developmental milestones.

EEG abnormality · Very frequent (99-80%)

Abnormality observed by electroencephalogram (EEG), which is used to record of the brain's spontaneous electrical activity from multiple electrodes placed on the scalp.

Feeding difficulties · Very frequent (99-80%)

Impaired ability to eat related to problems gathering food and getting ready to suck, chew, or swallow it.

Gait disturbance · Very frequent (99-80%)

The term gait disturbance can refer to any disruption of the ability to walk.

Intellectual disability · Very frequent (99-80%)

The term intellectual disability or intellectual developmental disorder is used to describe significantly sub-average intellectual and adaptive functioning based on clinical assessment and as measured by individually administered, appropriately normed, standardized and validated tests of intellectual functioning and adaptive behavior, with onset during the developmental period from infancy through adolescence.

Involuntary movements · Very frequent (99-80%)

Involuntary contractions of muscle leading to involuntary movements of extremities, neck, trunk, or face.

Reduced eye contact · Very frequent (99-80%)

A reduced frequency or duration of eye contact.

Seizure · Very frequent (99-80%)

A seizure is an intermittent abnormality of nervous system physiology characterized by a transient occurrence of signs and/or symptoms due to abnormal excessive or synchronous neuronal activity in the brain.

Sleep abnormality · Very frequent (99-80%)

An abnormal pattern in the quality, quantity, or characteristics of sleep.

Stereotypical hand wringing · Very frequent (99-80%)

Habitual clasping and wringing of the hands in the middle of the body, similar to a hand-washing movement.

Other findings in the same source

From: Orphanet

Additional reported features include Functional motor deficit (Very frequent (99-80%)); Loss of speech (Very frequent (99-80%)); Apraxia (Frequent (79-30%)); Dystonia (Frequent (79-30%)); Episodic tachypnea (Frequent (79-30%)); Functional abnormality of the gastrointestinal tract (Frequent (79-30%)); Gait ataxia (Frequent (79-30%)); Hand apraxia (Frequent (79-30%)); Hypotonia (Frequent (79-30%)); Inability to walk (Frequent (79-30%)). This is a selected summary, not a complete description of the condition.

When it may begin

From: Orphanet

Neonatal

Inheritance in the source

From: Orphanet

Autosomal dominant; X-linked dominant

Frequency and the population described

From: Orphanet

Point prevalence: 1-9 / 100 000; Worldwide; Value and class.

Which doctor should you see?

The suggested department for discussing Atypical Rett syndrome is Neurology, with a neurologist as the relevant type of clinician. General physician / Family Medicine; paediatrician for children. Referral depends on symptoms.

Additional services that may be relevant, depending on the findings, include: Clinical Genetics.

This is an editorial referral starting point. The appropriate clinic depends on the person’s age, symptoms, previous diagnosis and local services. The first clinician can decide whether another specialty or a team is needed; a department label does not confirm the diagnosis.

How to prepare for an assessment

Bring a short timeline of the main symptoms: when they first appeared, whether they are constant or episodic, what seems to change them, and how they affect daily activities. Include previous reports, discharge summaries, current medicines and supplements, allergies, and any relevant family history. A dated record is more useful than trying to match every feature in an online article.

Ask the clinician what is already established and what remains uncertain. If a test is suggested, ask what question it answers, what its limitations are and how the result would change the next step. The information here is not an instruction to arrange every possible test. In children, bring growth, developmental and school information if it is relevant to the concern.

• Which nervous-system findings help explain the symptoms?
• Would an assessment of walking, communication or daily function be helpful?
• Are rehabilitation or other specialist services relevant?

Treatment discussions and follow-up

The material gathered for this draft does not provide a complete condition-specific treatment pathway for Atypical Rett syndrome. That gap does not mean that treatment is unavailable. A clinician needs to establish the diagnosis and review current guidance before recommending medicines, procedures, rehabilitation or other support.

Before leaving the appointment, clarify the next review date, who will communicate results, and whom to contact if the situation changes. Discuss difficulties with sleep, work, school, mobility, eating or emotional wellbeing when these are relevant. Practical support may require coordination between the treating clinician and other services.

The collected references do not establish a complete prevention or long-term outlook section for this entry. Missing information should not be interpreted as proof that prevention is impossible or that a particular outcome is inevitable. Ask what is known for the exact subtype, stage and personal circumstances, and which uncertainties remain.

When to seek emergency help

Severe breathing difficulty, collapse, new stroke-like symptoms, a seizure that is prolonged or repeated without recovery, uncontrolled major bleeding, or an immediate risk of self-harm require emergency help. In India, call 112 or reach the nearest emergency department. This is a general, non-exhaustive warning list; it is not a condition-specific triage tool.