Cherubism

A rare genetic disorder affecting the jaw and facial bones

Cherubism is a rare genetic disorder characterized by abnormal bone tissue in the lower part of the face, particularly the jaw and cheekbones. This condition is named for the "cherubic" appearance it imparts to affected individuals, due to the swelling of the cheeks and jaw.

Presentation

Cherubism typically manifests in early childhood, often between the ages of 2 and 7. The primary feature of cherubism is the painless, symmetrical swelling of the jaw and cheeks. This swelling is due to the replacement of normal bone with fibrous tissue, leading to the characteristic facial appearance.

File:Cherubism face.jpg

A child with cherubism showing characteristic facial swelling.

As the child grows, the swelling may become more pronounced, but it often stabilizes or regresses after puberty. In some cases, the condition can lead to dental abnormalities, such as misalignment of teeth, delayed eruption, or missing teeth.

Genetics

Cherubism is inherited in an autosomal dominant pattern, meaning that a single copy of the altered gene in each cell is sufficient to cause the disorder. The condition is associated with mutations in the SH3BP2 gene, which plays a role in bone remodeling and immune system function.

Pathophysiology

The pathophysiology of cherubism involves the replacement of normal bone with fibrous tissue, leading to the formation of cyst-like lesions in the jaw. These lesions are filled with multinucleated giant cells and fibrous stroma. The exact mechanism by which mutations in the SH3BP2 gene lead to these changes is not fully understood, but it is believed to involve dysregulation of osteoclast activity and inflammatory pathways.

Diagnosis

Diagnosis of cherubism is typically based on clinical examination and radiographic findings. X-rays or CT scans of the jaw reveal characteristic "soap bubble" or multilocular radiolucencies. Genetic testing can confirm the diagnosis by identifying mutations in the SH3BP2 gene.

Management

Management of cherubism is primarily supportive and focuses on monitoring the progression of the condition. In many cases, no treatment is necessary, as the condition often stabilizes or improves after puberty. However, surgical intervention may be considered in severe cases to correct facial deformities or address functional issues such as dental malocclusion.

Prognosis

The prognosis for individuals with cherubism is generally good, as the condition often stabilizes or regresses with age. Most individuals lead normal lives, although they may experience some degree of facial disfigurement or dental issues.

Related pages

• Fibrous dysplasia
• Osteogenesis imperfecta
• Paget's disease of bone