Cleidocranial Dysplasia
Description
Cleidocranial Dysplasia (CCD) is a rare genetic disorder that affects bone development, primarily affecting the skull, clavicles (collarbones), and teeth. Individuals with CCD may experience a range of symptoms, from mild to severe, and the condition can present differently from person to person. This blog provides a comprehensive guide to understanding CCD, including its causes, symptoms, diagnosis, management, and ways individuals with CCD can thrive.
Genes Involved
Genes Involved:
Cleidocranial Dysplasia is primarily caused by mutations in the RUNX2 gene. This gene provides instructions for making a protein that plays a crucial role in bone development. Mutations in RUNX2 can disrupt the normal process of bone formation, leading to the characteristic features of CCD.
Recognizing the Signs and Symptoms
Recognizing the Signs and Symptoms:
- Delayed closure of the fontanelles (soft spots) in the skull: This can lead to a larger head size and a prominent forehead.
- Hypoplastic or absent clavicles: This may allow the shoulders to meet in front of the chest, giving the appearance of hypermobility.
- Delayed or missing teeth: This can include delayed eruption, missing teeth, or abnormal tooth shape.
- Delayed ossification of the skull: This can result in a dome-shaped head with a prominent forehead and a smaller facial appearance.
- Short stature: While not always present, some individuals with CCD may have shorter stature.
- Other skeletal abnormalities: These may include delayed bone development in the hands, feet, and pelvis.
- Hearing loss: CCD can sometimes affect the bones of the middle ear, leading to hearing loss.
Causes
Causes:
Cleidocranial Dysplasia is an inherited disorder. It is caused by mutations in the RUNX2 gene, which is responsible for regulating bone development. These mutations can be passed down from a parent to their child. In some cases, the mutation may be spontaneous, meaning it is not inherited from a parent.
Inheritance/recurrence risk
Inheritance or Recurrence Risk:
CCD is inherited in an autosomal dominant pattern. This means that if one parent has the mutated RUNX2 gene, there is a 50% chance of their child inheriting the condition. If both parents have the mutation, there is a 75% chance of their child inheriting CCD. In some cases, the mutation may occur spontaneously, meaning it is not inherited from a parent. In these cases, the risk of recurrence in future pregnancies is low.
