X-linked female restricted facial dysmorphism-short stature-choanal atresia-intellectual disability

What it is

From: Orphanet

A rare genetic multiple congenital anomalies/dysmorphic syndrome characterized by global developmental delay, intellectual disability, and dysmorphic facial features (such as facial asymmetry, prominent forehead, short palpebral fissures, low nasal bridge, smooth and long philtrum, thin upper lip, and low-set, posteriorly rotated, dysplastic ears), exclusively affecting females. Additional reported manifestations include short stature, choanal atresia, scoliosis, congenital ocular, dental, cardiac, and urogenital anomalies, as well as hypotonia, seizures, and structural brain abnormalities, among others.

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.

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.

Intellectual disability, moderate · Very frequent (99-80%)

Moderate intellectual disability (ID) is defined as a type of ID characterized by moderately sub-average adaptive functioning and intellectual functioning, with an intelligence quotient (IQ) the range of 35-49.

Abnormal cortical gyration · Frequent (79-30%)

An abnormality of the gyri (i.e., the ridges) of the cerebral cortex of the brain.

Abnormality of the eye · Frequent (79-30%)

Any abnormality of the eye, including location, spacing, and intraocular abnormalities.

Abnormality of the genitourinary system · Frequent (79-30%)

The presence of any abnormality of the genitourinary system.

Anal atresia · Frequent (79-30%)

Congenital absence of the anus, i.e., the opening at the bottom end of the intestinal tract.

Choanal atresia · Frequent (79-30%)

Absence or abnormal closure of the choana (the posterior nasal aperture). Most embryologists believe that posterior choanal atresia results from a failure of rupture between the 35th and 38th day of fetal life of the partition which separates the bucconasal or buccopharyngeal membranes. The resultant choanal atresia may be unilateral or bilateral, bony or membranous, complete or incomplete. In over 90 per cent of cases the obstruction is bony, while in the remainder it is membranous. The bony type of atresia is commonly located 1-2 mm. anterior to the posterior edge of the hard palate, and the osseous septum varies in thickness from 1 to 10 mm. In the membranous form of choanal atresia the obstruction usually occurs further posteriorly. In approximately one third of cases the atresia is bilateral.

Dandy-Walker malformation · Frequent (79-30%)

A congenital brain malformation typically characterized by incomplete formation of the cerebellar vermis, dilation of the fourth ventricle, and enlargement of the posterior fossa. In layman's terms, Dandy Walker malformation is a cyst in the cerebellum (typically symmetrical) that is involved with the fourth ventricle. This may interfere with the ability to drain cerebrospinal fluid from the brain, resulting in hydrocephalus. Dandy Walker cysts are formed during early embryonic development, while the brain forms. The cyst in the cerebellum typically has several blood vessels running through it connecting to the brain, thereby prohibiting surgical removal.

Floppy infant · Frequent (79-30%)

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).

Hypoplasia of the corpus callosum · Frequent (79-30%)

Underdevelopment of the corpus callosum.

Postaxial polydactyly · Frequent (79-30%)

A form of polydactyly in which the extra digit or digits are localized on the side of the fifth finger or fifth toe.

Short stature · Frequent (79-30%)

A height below that which is expected according to age and gender norms. Although there is no universally accepted definition of short stature, many refer to "short stature" as height more than 2 standard deviations below the mean for age and gender (or below the 3rd percentile for age and gender dependent norms).

Depigmentation/hyperpigmentation of skin · Frequent (79-30%)

Abnormal thyroid hormone level · Occasional (29-5%)

Any deviation from the normal range of the hormones produced by the thyroid gland.

Other findings in the same source

From: Orphanet

Additional reported features include Abnormality of the abdominal wall (Occasional (29-5%)); Abnormality of the dentition (Occasional (29-5%)); Abnormality of the periodontium (Occasional (29-5%)); Astigmatism (Occasional (29-5%)); Atrial septal defect (Occasional (29-5%)); Brachycephaly (Occasional (29-5%)); Brain atrophy (Occasional (29-5%)); Cardiomyopathy (Occasional (29-5%)); Cataract (Occasional (29-5%)); Cerebellar hypoplasia (Occasional (29-5%)). This is a selected summary, not a complete description of the condition.

When it may begin

From: Orphanet

Antenatal; Infancy; Neonatal

Inheritance in the source

From: Orphanet

X-linked dominant

Frequency and the population described

From: Orphanet

Reported case(s): 17.0; 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 dominant pattern involves a gene on the X chromosome. Expression can differ between individuals and between sexes. Family counselling requires the actual genetic finding and a clear family history; a general description cannot calculate the risk or severity for a particular child.

Which doctor should you see?

The suggested department for discussing X-linked female restricted facial dysmorphism-short stature-choanal atresia-intellectual disability 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 female restricted facial dysmorphism-short stature-choanal atresia-intellectual disability. 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.