X-linked intellectual disability-global development delay-facial dysmorphism-sacral caudal remnant syndrome

What it is

From: Orphanet

A rare multiple congenital anomalies/dysmorphic syndrome characterized by global developmental delay, intellectual disability, growth retardation, hearing impairment, characteristic facial dysmorphology (including prominent supraorbital ridges, downslanting palpebral fissures, deep-set eyes, long face, sagging cheeks, anteverted nares, and pointed chin), generalized hypotonia, joint hypermobility, gluteal crease with sacral caudal remnant and sacral dimple, and variable neurological features. Various ophthalmic, cutaneous, musculoskeletal, gastrointestinal, and cardiovascular anomalies have also been described.

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 facial shape · Very frequent (99-80%)

An abnormal morphology (form) of the face or its components.

Abnormal sacral segmentation · Very frequent (99-80%)

An abnormality related to a defect of vertebral separation of sacral vertebrae during development.

Delayed gross motor development · Very frequent (99-80%)

A type of motor delay characterized by a delay in acquiring the ability to control the large muscles of the body for walking, running, sitting, and crawling.

Delayed speech and language development · Very frequent (99-80%)

A degree of language development that is significantly below the norm for a child of a specified age.

Generalized hypotonia · Very frequent (99-80%)

Generalized muscular hypotonia (abnormally low muscle tone).

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.

Hypoplasia of the corpus callosum · Very frequent (99-80%)

Underdevelopment of the corpus callosum.

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.

Low-set ears · Very frequent (99-80%)

Upper insertion of the ear to the scalp below an imaginary horizontal line drawn between the inner canthi of the eye and extending posteriorly to the ear.

Postnatal growth retardation · Very frequent (99-80%)

Slow or limited growth after birth.

Protruding ear · Very frequent (99-80%)

Angle formed by the plane of the ear and the mastoid bone greater than the 97th centile for age (objective); or, outer edge of the helix more than 2 cm from the mastoid at the point of maximum distance (objective).

Severe expressive language delay · Very frequent (99-80%)

A severe delay in the acquisition of the ability to use language to communicate needs, wishes, or thoughts.

Prominent protruding coccyx · Very frequent (99-80%)

Anteverted nares · Frequent (79-30%)

Anteriorly-facing nostrils viewed with the head in the Frankfurt horizontal and the eyes of the observer level with the eyes of the subject. This gives the appearance of an upturned nose (upturned nasal tip).

Other findings in the same source

From: Orphanet

Additional reported features include Autistic behavior (Frequent (79-30%)); Chronic otitis media (Frequent (79-30%)); Downslanted palpebral fissures (Frequent (79-30%)); Hearing impairment (Frequent (79-30%)); High palate (Frequent (79-30%)); Intellectual disability, moderate (Frequent (79-30%)); Joint hypermobility (Frequent (79-30%)); Long face (Frequent (79-30%)); Long philtrum (Frequent (79-30%)); Pointed chin (Frequent (79-30%)). This is a selected summary, not a complete description of the condition.

When it may begin

From: Orphanet

Antenatal; Neonatal

Inheritance in the source

From: Orphanet

X-linked recessive

Frequency and the population described

From: Orphanet

Reported case(s): 14.0; 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 X-linked recessive pattern involves a gene on the X chromosome. The number of X chromosomes and the particular genetic change influence how a condition is expressed. A genetic counsellor should interpret the result and the family history before discussing risks for relatives or future pregnancies.

Which doctor should you see?

The suggested department for discussing X-linked intellectual disability-global development delay-facial dysmorphism-sacral caudal remnant syndrome is Clinical Genetics, with a clinical geneticist as the relevant type of clinician. Paediatrician (children) or physician (adults), with clinical geneticist referral.

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.

• Does the exact genetic or chromosome finding explain the observed features?
• Would a genetic counsellor help the family understand the result?
• Which organ-specific assessments are appropriate for this particular diagnosis?

Treatment discussions and follow-up

The material gathered for this draft does not provide a complete condition-specific treatment pathway for X-linked intellectual disability-global development delay-facial dysmorphism-sacral caudal remnant 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.