Cherubism

What it is, symptoms and effects

From: MedlinePlus Genetics, National Library of Medicine

Cherubism is a disorder characterized by abnormal bone tissue in the jaw. Beginning in early childhood, both the lower jaw (the mandible) and the upper jaw (the maxilla) become enlarged as bone is replaced with painless, cyst-like growths. These growths give the cheeks a swollen, rounded appearance and often interfere with normal tooth development. In some people the condition is so mild that it may not be noticeable, while other cases are severe enough to cause problems with vision, breathing, speech, and swallowing. Enlargement of the jaw usually continues throughout childhood and stabilizes during puberty. The abnormal growths are gradually replaced with normal bone in early adulthood. As a result, many affected adults have a normal facial appearance.

Most people with cherubism have few, if any, signs and symptoms affecting other parts of the body. Rarely, however, this condition occurs as part of another genetic disorder. For example, abnormal jaw growth, like that in cherubism, can occur in Ramon syndrome, which also involves short stature, intellectual disability, and overgrowth of the gums (gingival fibrosis). Additionally, cherubism-like growths have been reported in rare cases of Noonan syndrome (a developmental disorder characterized by unusual facial characteristics, short stature, and heart defects), fragile X syndrome (a condition primarily affecting males that causes learning disabilities and cognitive impairment), and neurofibromatosis type 1 (a condition primarily characterized by multiple skin tumors).

Causes and biological mechanisms

From: MedlinePlus Genetics, National Library of Medicine

Mutations in the SH3BP2 gene have been identified in about 80 percent of people with cherubism. In most of the remaining cases, the genetic cause of the condition is unknown.

The SH3BP2 gene provides instructions for making a protein that plays a role in relaying chemical signals within cells. the SH3BP2 protein is particularly important for the function of cells involved in the replacement of old bone tissue with new bone (bone remodeling) and certain immune system cells.

Mutations in the SH3BP2 gene lead to production of an abnormal protein that does not get broken down when it is no longer needed. Too much SH3BP2 protein likely increases signaling in certain cells, causing an immune reaction (inflammation) in the jaw bones and also triggering the production of osteoclasts, which are cells that break down bone tissue during bone remodeling. An excess of these bone-destroying cells contributes to the destruction of bone in the upper and lower jaws. A combination of bone loss and inflammation likely underlies the cyst-like growths characteristic of cherubism.

When cyst-like growths in the jaw, like those in cherubism, occur as a feature of a genetic syndrome, they are caused by the genetic alteration involved in the syndrome rather than by an SH3BP2 alteration.

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.

How common is it?

From: MedlinePlus Genetics, National Library of Medicine

The incidence of cherubism is unknown. Nearly 350 cases have been reported 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.

Abnormality of the mandible · Very frequent (99-80%)

Any abnormality of the mandible, the bone of the lower jaw.

Bone cyst · Very frequent (99-80%)

A fluid filled cavity that develops with a bone.

Broad jaw · Very frequent (99-80%)

Bigonial distance (lower facial width) more than 2 SD above the mean (objective); or an apparently increased width of the lower jaw (mandible) when viewed from the front (subjective).

Full cheeks · Very frequent (99-80%)

Increased prominence or roundness of soft tissues between zygomata and mandible.

Abnormal dental morphology · Frequent (79-30%)

An abnormality of the morphology of the tooth.

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

Any abnormality of the teeth.

Oligodontia · Frequent (79-30%)

The absence of six or more teeth from the normal series by a failure to develop.

Feeding difficulties in infancy · Occasional (29-5%)

Impaired feeding performance of an infant as manifested by difficulties such as weak and ineffective sucking, brief bursts of sucking, and falling asleep during sucking. There may be difficulties with chewing or maintaining attention.

Other findings in the same source

From: Orphanet

Additional reported features include Obstructive sleep apnea (Occasional (29-5%)); Optic atrophy (Occasional (29-5%)); Progressive visual loss (Occasional (29-5%)); Proptosis (Occasional (29-5%)); Upper airway obstruction (Occasional (29-5%)); Visual impairment (Occasional (29-5%)); Abnormality of the voice (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 Cherubism is Orthopaedics, with a orthopaedic specialist 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.

• What explains the change in pain, movement or function?
• Which activities need adjustment while the diagnosis is being clarified?
• What are the roles of rehabilitation, observation and surgery in this situation?

Treatment discussions and follow-up

The material gathered for this draft does not provide a complete condition-specific treatment pathway for Cherubism. 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.