What Is Cleidocranial Dysplasia?

Cleidocranial dysplasia (CCD) is a rare genetic disorder that affects the development of the bones, skull, and teeth.
Cleidocranial dysplasia (CCD) is a rare genetic disorder that affects the development of the bones, skull, and teeth.

Cleidocranial dysplasia (CCD) is a rare genetic disorder that affects the development of the bones, skull, and teeth. The bones in people with CCD might be formed differently or maybe more fragile than usual. In some cases, the collar bone may be absent.

Cleido refers to the collar bone, and cranial refers to the skull; thus, cleidocranial refers to skull abnormalities. Some typical features of this condition in different areas include:

Skull and face:

  • Delayed maturation of the skull
  • Soft spots on the head that don’t harden
  • Delayed closing of growth lines where the bones of the skull meet
  • Flat feet
  • Scoliosis (abnormal curvature of the spine)
  • Brachycephaly (wide and short skull)
  • Prominent forehead
  • Wide-set eyes
  • Flat nose
  • Small upper jaw
  • Short shoulder blades
  • Depressed bridge of the nose
  • Wormian bones (an extra bone that can occur within a joint of the skull)
  • High-arched hard palate
  • Hearing loss
  • Recurrent sinus and ear infections

Teeth:

  • Delayed loss of the baby teeth
  • Delayed appearance of adult teeth
  • Unusually shaped teeth
  • Misalignment of the teeth and jaws
  • Abnormal tooth enamel
  • Crowded teeth
  • Supernumerary (extra) teeth
  • Thin tooth enamel leading to cavities

Other features:

  • Recurrent fractures
  • Sleep apnea (snoring)
  • Average intelligence
  • Narrow chest
  • Breathing difficulties
  • Hunch back
  • Poor fingernail or toenail formation
  • Extra or missing ribs
  • Shorter than average
  • Short, tapered fingers and broad thumb
  • Knock knees (a condition in which the knee bend inward towards the center of the body)
  • Deformities in pelvic bones complicating conception
  • Osteopenia (decreased bone density)
  • Narrow and sloping shoulder
  • Slow development of motor skills, such as crawling and walking
  • Fluid-filled cyst in the spinal cord

What causes cleidocranial dysplasia?

Cleidocranial dysplasia is caused due to mutations in the RUNX2 gene. This gene is responsible for the production of a protein that is involved in the development of the skeletal system. The RUNX2 gene mutations interfere with the development of bone, teeth, and cartilage. The condition is autosomal dominant. There is a 50% chance that the child will suffer from the disease if one parent has the disease. Sometimes, there may be a spontaneous mutation and the child may show signs of the disease though parents are normal.

What is the treatment for cleidocranial dysplasia?

Treatment depends on the individual’s symptoms. The individual has to undergo numerous reconstructive surgery and dental procedures for functional well-being. Treatment includes:

  • Facial reconstructive surgery to reshape the forehead and cheekbones in children
  • Spinal fusion procedures to strengthen the spinal cord
  • Surgical repair of fractures due to weak bones
  • Surgical removal of small collar bone pieces affecting the network of nerves (brachial plexus). This can relieve the pain in the arm and nerve disorders due to compression.
  • Surgery to correct knock knees
  • Ear tubes to treat ear infection
  • Calcium and Vitamin D supplements to strengthen the bone
  • Oral surgery to correct extra teeth
  • Jaw surgery to correct jaws

As a precaution, wear a helmet while playing sports to prevent the head injury.

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References
https://medlineplus.gov/genetics/condition/cleidocranial-dysplasia/#inheritance

https://rarediseases.info.nih.gov/diseases/6118/cleidocranial-dysplasia

https://www.hopkinsmedicine.org/health/conditions-and-diseases/cleidocranial-dysplasia-ccd