EAST syndrome

What it is

From: Orphanet

A rare genetic disease characterized by the association of epilepsy, ataxia, sensorineural hearing impairment, and renal tubulopathy. Patients present in infancy with generalized seizures, cerebellar dysfunction (including gait ataxia, intention tremor, and dysdiadochokinesis), and variable developmental delay and sensorineural hearing loss. Laboratory studies show persistent hypokalemic metabolic acidosis with hypomagnesemia. Additional reported neurologic features include brisk deep tendon reflexes, ankle clonus, extensor plantar responses, or nystagmus.

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 urinary electrolyte concentration · Very frequent (99-80%)

An abnormality in the concentration of electrolytes in the urine.

Ataxia · Very frequent (99-80%)

Ataxia refers to impaired coordination of voluntary muscle movement. Cerebellar ataxia refers to ataxia due to dysfunction of the cerebellum. This causes a variety of elementary neurological deficits including asynergy (lack of coordination between muscles, limbs and joints), dysmetria (lack of ability to judge distances that can lead to under- or overshoot in grasping movements), and dysdiadochokinesia (inability to perform rapid movements requiring antagonizing muscle groups to be switched on and off repeatedly).

Generalized-onset seizure · Very frequent (99-80%)

A generalized-onset seizure is a type of seizure originating at some point within, and rapidly engaging, bilaterally distributed networks. The networks may include cortical and subcortical structures but not necessarily the entire cortex.

Global developmental delay · Very frequent (99-80%)

A delay in the achievement of motor or mental milestones in the domains of development of a child, including motor skills, speech and language, cognitive skills, and social and emotional skills. This term should only be used to describe children younger than five years of age.

Hypokalemia · Very frequent (99-80%)

The concentration of potassium(1+) in the blood circulation is below the lower limit of normal.

Hypomagnesemia · Very frequent (99-80%)

The concentration of magnesium in the blood circulation is below the lower limit of normal.

Increased circulating aldosterone concentration · Very frequent (99-80%)

Overproduction of the mineralocorticoid aldosterone by the adrenal cortex.

Increased circulating renin level · Very frequent (99-80%)

An increased level of renin in the blood.

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.

Metabolic alkalosis · Very frequent (99-80%)

Metabolic alkalosis is defined as a disease state where the pH is elevated to greater than 7.45 secondary to some metabolic process.

Renal magnesium wasting · Very frequent (99-80%)

High urine magnesium in the presence of hypomagnesemia.

Renal salt wasting · Very frequent (99-80%)

A high concentration of one or more electrolytes in the urine in the presence of low serum concentrations of the electrolyte(s).

Renal sodium wasting · Very frequent (99-80%)

An abnormally increased sodium concentration in the urine in the presence of hyponatremia.

Salt craving · Very frequent (99-80%)

Hypersalivation, also known as salt craving, refers to an excessive desire to consume salt (sodium chloride) or salty foods.

Other findings in the same source

From: Orphanet

Additional reported features include Seizure (Very frequent (99-80%)); Sensorineural hearing impairment (Very frequent (99-80%)); Action tremor (Frequent (79-30%)); Enuresis (Frequent (79-30%)); Polydipsia (Frequent (79-30%)); Absent speech (Occasional (29-5%)); Cerebellar atrophy (Occasional (29-5%)); Gait disturbance (Occasional (29-5%)); Inability to walk (Occasional (29-5%)); Lower limb muscle weakness (Occasional (29-5%)). This is a selected summary, not a complete description of the condition.

When it may begin

From: Orphanet

Infancy; Neonatal

Inheritance in the source

From: Orphanet

Autosomal recessive

Frequency and the population described

From: Orphanet

Reported case(s): 26.0; Worldwide. This is a published case count, not prevalence. Point prevalence: <1 / 1 000 000; Worldwide; Class only.

Understanding the inheritance label

From: MedlinePlus Genetics

An autosomal recessive pattern usually involves disease-causing changes in both copies of a gene. Parents may each carry one altered copy without having the condition themselves. A genetic counsellor can explain carrier testing and reproductive implications using the actual laboratory findings, rather than the condition name alone.

Which doctor should you see?

The suggested department for discussing EAST 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 EAST 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.