Cleidocranial Dysplasia (cleido = collar bone, + cranial = head, + dysplasia = abnormal forming), also known as Cleidocranial Dysostosis and Marie-Sainton Disease, is a condition characterized by defective development of the cranial bones and by the complete or partial absence of the collar bones (clavicles). Characteristics include:
- Delayed closure (ossification) of the space between the bones of the skull (fontanels)
- Premature closing of the coronal suture
- Protruding jaw (mandible) and protruding brow bone (frontal bossing)
- Wide nasal bridge due to increased space between the eyes (hypertelorism)
- High arched palate or possible cleft palate
- Short stature
- Scoliosis of the spine
Why did this happen?
There is no link between anything the mother did or did not do while she was pregnant and the occurrence of Cleidocranial Dysplasia.
It is transmitted as an autosomal dominant trait. CCD is caused by mutation in the RunX2 gene on Chromosome 6p21.
What are the symptoms and signs of cleidocranial dysplasia?
Signs and symptoms of cleidocranial dysplasia can vary widely in severity, even within the same family.
Individuals with cleidocranial dysplasia usually have underdeveloped or absent collarbones (clavicles). As a result, their shoulders are narrow and sloping, can be brought unusually close together in front of the body, and in some cases the shoulders can be made to meet in the middle of the body.
Delayed closing of the spaces between the bones of the skull (fontanels) is also characteristic of this condition. The fontanels usually close in early childhood, but may remain open into adulthood in people with this disorder.
Affected individuals may be 3 to 6 inches shorter than other members of their family, and may have:
- short, tapered fingers and broad thumbs;
- short forearms;
- flat feet;
- knock knees; and
- an abnormal curvature of the spine (scoliosis).
Characteristic facial features may include:
- a wide, short skull (brachycephaly);
- a prominent forehead;
- wide-set eyes (hypertelorism); a
- flat nose; and a
- small upper jaw.
Individuals with cleidocranial dysplasia may have decreased bone density (osteopenia) and may develop osteoporosis, a condition that makes bones progressively more brittle and prone to fracture, at a relatively early age.
Women with cleidocranial dysplasia have an increased risk of requiring a cesarean section when delivering a baby, due to a narrow pelvis preventing passage of the infant’s head.
Dental abnormalities seen in cleidocranial dysplasia may include:
- delayed loss of the primary (baby) teeth;
- delayed appearance of the secondary (adult) teeth;
- unusually shaped, peg-like teeth;
- misalignment of the teeth and jaws (malocclusion); and
- extra teeth, sometimes accompanied by cysts in the gums.
In addition to skeletal and dental abnormalities, people with cleidocranial dysplasia may have hearing loss and be prone to sinus and ear infections.
Some young children with this condition are mildly delayed in the development of motor skills such as crawling and walking, but intelligence is unaffected.
Will this happen to children I have in the future?
If both parents are unaffected, it is called a spontaneous genetic mutation and the chances of having another child with it are very small.
If one parent is affected, it is called an inherited genetic mutation and there is a 50% chance that a child will have it.
Of all the cases of Cleidocranial Dysplasia, one-third are spontaneous and two-thirds are genetic.
What kinds of problems could my child have?
In addition to the physical characteristics common to Cleidocranial Dysplasia, your child may have the following problems:
- Dental abnormalities – failure to lose the baby teeth (deciduous) at the expected time; slow eruption of secondary teeth; extra teeth; delayed or absent formation of teeth
- Ability to touch the shoulders together in front of the body
- Wide pelvic bone
- Loose joints
- Hearing loss and/or frequent infections
How common is cleidocranial dysplasia?
Cleidocranial dysplasia occurs in approximately 1 per million individuals worldwide.
How do people inherit cleidocranial dysplasia?
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 mutation from one affected parent.
Other cases may result from new mutations in the gene. These cases occur in people with no history of the disorder in their family.
Will my child need surgery?
Due to the fact that the dental problems are the most significant complications, appropriate dental/orthodontic work is vital. Some of the suggested treatment options include the following:
- Apply dentures over the unerupted teeth
- Teeth removal as they erupt, because very little bone structure would be left if the supernumerary, impacted, and unerupted teeth were all extracted at once
- Some doctors suggest that the removal of primary or supernumerary teeth does not promote eruption of unerupted permanent teeth. In addition, permanent teeth may be difficult to extract due to malformed roots.
Where can I find information about treatment for cleidocranial dysplasia?
These resources address the management of cleidocranial dysplasia and may include treatment providers.