Char syndrome

What it is, symptoms and effects

From: MedlinePlus Genetics, National Library of Medicine

Char syndrome is a condition that affects the development of the face, heart, and limbs. It is characterized by a combination of three major features: a distinctive facial appearance, a heart defect called patent ductus arteriosus, and hand abnormalities.

Most people with Char syndrome have a characteristic facial appearance that includes flattened cheek bones and a flat nasal bridge (the area of the nose between the eyes). The tip of the nose is also flat and broad. The eyes are wide-set with droopy eyelids (ptosis) and outside corners that point downward (down-slanting palpebral fissures). Additional facial differences include a shortened distance between the nose and upper lip (a short philtrum), a triangular-shaped mouth, and thick, prominent lips.

Patent ductus arteriosus is a common heart defect in newborns, and it occurs in most babies with Char syndrome. Before birth, the ductus arteriosus forms a connection between two major arteries (the aorta and the pulmonary artery). This connection normally closes shortly after birth, but it remains open in babies with patent ductus arteriosus. If untreated, this heart defect causes infants to breathe rapidly, feed poorly, and gain weight slowly. In severe cases, it can lead to heart failure. People with patent ductus arteriosus also have an increased risk of infection.

Hand abnormalities are another feature of Char syndrome. In most people with this condition, the middle section of the fifth (pinky) finger is shortened or absent. Other abnormalities of the hands and feet have been reported but are less common.

Causes and biological mechanisms

From: MedlinePlus Genetics, National Library of Medicine

Variants (also known as mutations) in the TFAP2B gene cause Char syndrome. This gene provides instructions for making a protein known as transcription factor AP-2β. A transcription factor is a protein that attaches (binds) to specific regions of DNA and helps control the activity of particular genes. Transcription factor AP-2β regulates genes that are involved in development before birth. In particular, this protein appears to play a role in the normal formation of structures in the face, heart, and limbs.

TFAP2B variants alter the structure of transcription factor AP-2β. Some of these variants prevent the protein from binding to DNA, while other variants render it unable to regulate the activity of other genes. A loss of this protein's function disrupts the normal development of several parts of the body before birth, resulting in the major features of Char syndrome.

Inheritance and family implications

From: MedlinePlus Genetics, National Library of Medicine

This condition is inherited in an autosomal dominant pattern, which means one copy of the altered gene in each cell is sufficient to cause the disorder.

In some cases, an affected person inherits the variant from one affected parent. Other cases may result from new variants in the gene and occur in people with no history of the disorder in their family.

How common is it?

From: MedlinePlus Genetics, National Library of Medicine

Char syndrome is rare, although its exact incidence is unknown. Only a few families with this condition have been identified worldwide.

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.

Depressed nasal bridge · Very frequent (99-80%)

Posterior positioning of the nasal root in relation to the overall facial profile for age.

Depressed nasal ridge · Very frequent (99-80%)

Lack of prominence of the nose resulting from a posteriorly-placed nasal ridge.

Downslanted palpebral fissures · Very frequent (99-80%)

The palpebral fissure inclination is more than two standard deviations below the mean.

Everted lower lip vermilion · Very frequent (99-80%)

An abnormal configuration of the lower lip such that it is turned outward i.e., everted, with the Inner aspect of the lower lip vermilion (normally opposing the teeth) being visible in a frontal view.

Hypertelorism · Very frequent (99-80%)

Interpupillary distance more than 2 SD above the mean (alternatively, the appearance of an increased interpupillary distance or widely spaced eyes).

Malar flattening · Very frequent (99-80%)

Underdevelopment of the malar prominence of the jugal bone (zygomatic bone in mammals), appreciated in profile, frontal view, and/or by palpation.

Patent ductus arteriosus · Very frequent (99-80%)

In utero, the ductus arteriosus (DA) serves to divert ventricular output away from the lungs and toward the placenta by connecting the main pulmonary artery to the descending aorta. A patent ductus arteriosus (PDA) in the first 3 days of life is a physiologic shunt in healthy term and preterm newborn infants, and normally is substantially closed within about 24 hours after bith and completely closed after about three weeks. Failure of physiologcal closure is referred to a persistent or patent ductus arteriosus (PDA). Depending on the degree of left-to-right shunting, PDA can have clinical consequences.

Ptosis · Very frequent (99-80%)

The upper eyelid margin is positioned 3 mm or more lower than usual and covers the superior portion of the iris (objective); or, the upper lid margin obscures at least part of the pupil (subjective).

Other findings in the same source

From: Orphanet

Additional reported features include Short philtrum (Very frequent (99-80%)); Thick vermilion border (Very frequent (99-80%)); Triangular mouth (Very frequent (99-80%)); Clinodactyly of the 5th finger (Frequent (79-30%)); Mesoaxial hand polydactyly (Frequent (79-30%)); Short middle phalanx of the 5th finger (Frequent (79-30%)); Agenesis of permanent teeth (Occasional (29-5%)); Global developmental delay (Occasional (29-5%)); Hand polydactyly (Occasional (29-5%)); Hearing impairment (Occasional (29-5%)). This is a selected summary, not a complete description of the condition.

Which doctor should you see?

The suggested department for discussing Char 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

Where the source describes treatments, these are an overview of possible care, not a prescription for an individual. Ask which option applies to the confirmed diagnosis, what benefit is expected, what adverse effects to watch for and how progress will be assessed. Availability, approvals and local practice can differ from the country described in the source.

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.