Infantile hypotonia-oculomotor anomalies-hyperkinetic movements-developmental delay syndrome

What it is

From: Orphanet

A rare genetic neurological disorder characterized by infantile hypotonia, congenital ophthalmic anomalies (including strabismus, esotropia, nystagmus, and central visual impairment), global developmental delay and intellectual disability, behavioral abnormalities, and movement disorder (such as dystonia, chorea, hyperkinesia, stereotypies). Mild facial dysmorphism and skeletal deformities have also been reported. EEG testing shows marked abnormalities in the absence of overt epileptic seizures.

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.

Absent speech · Very frequent (99-80%)

Complete lack of development of speech and language abilities.

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.

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.

Floppy infant · Very frequent (99-80%)

Floppiness/hypotonia is defined as reduced resistance to passive movement of joints. Physical examination of floppy/hypotonic infants shows head lag, lack of shoulder and elbow muscle contraction on traction response, inability to tighten the shoulder girdle muscles (or slipping through) when held under the axillae, scarf sign (when the arm is pulled to the opposite side, the arm wraps around the neck with the elbow crossing midline), hyperdorsiflexion of the feet, easy apposition of the thumb against the forearm, feet touching the cheek with ease and without discomfort, frog leg position, and inverted U sign on ventral suspension (head, arms, and legs hanging down without elbow or knee flexion and the trunk rounded in a dome shape).

Motor delay · Very frequent (99-80%)

A type of Developmental delay characterized by a delay in acquiring motor skills.

Severe global developmental delay · Very frequent (99-80%)

A severe delay in the achievement of motor or mental milestones in the domains of development of a child.

Abnormal repetitive mannerisms · Frequent (79-30%)

Use of the same abnormal action in response to certain triggers or at random. They may be used as a way to regulate one's internal state but must otherwise have no apparent functional purpose.

Esotropia · Frequent (79-30%)

A form of strabismus with one or both eyes turned inward ('crossed') to a relatively severe degree, usually defined as 10 diopters or more.

Gastroesophageal reflux · Frequent (79-30%)

A condition in which the stomach contents leak backwards from the stomach into the esophagus through the lower esophageal sphincter.

Hyperkinetic movements · Frequent (79-30%)

Motor hyperactivity with excessive movement of muscles of the body as a whole.

Intellectual disability · Frequent (79-30%)

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.

Nystagmus · Frequent (79-30%)

Rhythmic, involuntary oscillations of one or both eyes related to abnormality in fixation, conjugate gaze, or vestibular mechanisms.

Poor visual behavior for age · Frequent (79-30%)

Lack of visual responsiveness or decrease in visual capabilities suggesting a lack of visual responsiveness or decrease in visual capabilities in an infant or young child in which visual behavior fails to meet normal developmental milestones.

Reduced eye contact · Frequent (79-30%)

A reduced frequency or duration of eye contact.

Other findings in the same source

From: Orphanet

Additional reported features include Sleep abnormality (Frequent (79-30%)); Strabismus (Frequent (79-30%)); Vomiting (Frequent (79-30%)); Repetitive compulsive behavior (Frequent (79-30%)); 2-3 toe syndactyly (Occasional (29-5%)); Abnormal location of the eyebrow (Occasional (29-5%)); Agitation (Occasional (29-5%)); Almond-shaped palpebral fissure (Occasional (29-5%)); Anxiety (Occasional (29-5%)); Ataxia (Occasional (29-5%)). This is a selected summary, not a complete description of the condition.

When it may begin

From: Orphanet

Infancy

Inheritance in the source

From: Orphanet

Autosomal dominant

Frequency and the population described

From: Orphanet

Reported case(s): 11.0; 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 dominant pattern means that one altered copy of a relevant gene can be sufficient for the condition. Some affected people inherit the change; others have a new change without an affected parent. The precise finding, family history and condition determine what this means for relatives.

Which doctor should you see?

The suggested department for discussing Infantile hypotonia-oculomotor anomalies-hyperkinetic movements-developmental delay 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 Infantile hypotonia-oculomotor anomalies-hyperkinetic movements-developmental delay 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.