Cleidocranial Dysostosis: What is it? Causes, Symptoms, Complications, Diagnosis and Treatment

It is a hereditary congenital skeletal condition; it is present at birth.

It is characterized by delayed closure of the cranial vault sutures (the junctions between the bones that make up the cranial vault), hypoplastic or absent aplastic clavicles, and multiple dental anomalies.

SchItuthauer independently described it in 1871 and Marie and Sainton in 1897.

Cleidocranial dysostosis is a rare condition that involves dysplasia or abnormal development of specific bones in the body.

Cleidocranial dysostosis is very rare, occurring in about 1 in 1,000,000 people.

The condition is characterized by a large, open fontanel (soft spot on the skull), underdevelopment of the facial bones, abnormal teeth, and hypoplasia (underdevelopment) of the clavicles.

Cleidocranial dysostosis is also known as cleidocranial dysplasia or Marie-Sainton syndrome.

 

Causes of cleidocraneal dysostosis

Cleidocranial dysostosis is caused by a mutation in the RUNX2 gene or a Runt-related transcription factor.

This gene is essential in the differentiation and development of osteoblasts (cells that produce bone) and the skeleton’s story.

Cleidocranial dysostosis is inherited in an autosomal dominant fashion, meaning that only one copy of the gene is needed to develop the disease.

This means that a parent with cleidocranial dysostosis has a 50% chance that their child will have the disease.

Alternatively, the mutation can occur sporadically without inheriting the abnormal gene from a parent.

Symptoms of cleidocranial dysostosis

People with cleidocranial dysostosis usually have an average life expectancy.

Intelligence and development tend to be expected, but many physical characteristics characterize the condition.

Patients can have recurrent sinus infections, and about 1/3 develop hearing loss.

Symptoms can vary greatly, even within the same family.

Patients with cleidocranial dysostosis may have several developmental abnormalities related to hypoplasia of specific bones.

Typically, people with cleidocranial dysostosis exhibit skeletal, facial, and dental abnormalities.

Skeleton

  • Delayed closure of the skull bones (usually in adulthood rather than as a child). The anterior fontanelle (soft spot) in the skull is often large at birth and can remain open even into adulthood.
  • Underdeveloped or absent spines result in narrow, sloping shoulders. The clavicles are frequently hypoplastic, leading to sloping shoulders often touching each other in the midline.
  • Premature closure of the coronal suture.
  • Scoliosis.
  • Short stature (usually 3 to 6 inches shorter than other family members). Patients tend to be faster than their unaffected siblings.
  • Short forearms.
  • Short, tapered fingers and broad thumbs. There may be abnormalities in the hands, such as brachydactyly (short fingers) and fast and overall thumbs.
  • Abnormal shape of the pelvic bone.
  • Flatfoot. Patients can develop other skeletal abnormalities, such as flat feet (flat feet).
  • Knees that come together.

Facial features

The broad nasal bridge leads to a wide, protruding forehead with a persistent bony gap.

The middle face or upper jaw may be hypoplastic or underdeveloped, with a prominent lower jaw. It also causes widely spaced eyes, known as hypertelorism.

Dental abnormalities

Patients often have dental abnormalities, such as the late eruption of secondary or ‘adult’ teeth, lack of primary or milk teeth detachment, malocclusions or crowding (crooked or misaligned teeth), redundant teeth (extra) teeth), deformed teeth, or unusually formed.

Complications associated with cleidocranial dysostosis

The various bone and dental deformities associated with cleidocranial dysostosis can cause complications in people with this condition.

  • Decreased bone density leads to osteoporosis.
  • I heard loss.
  • Recurrent ear and sinus infections.
  • Mild delay in developing motor skills, such as crawling or walking.
  • Very flexible joints.
  • I was chewing and eating problems due to dental abnormalities.
  • High rate of cesarean sections for women due to an abnormally shaped pelvis.

Diagnosis of cleidocraneal dysostosis

The condition can be diagnosed before or after birth.

Before birth

The fetus’ DNA can be taken for testing.

This is usually only done for high-risk pregnancies when one of the parents has cleidocranial dysostosis.

It can also be diagnosed by ultrasound to look for specific characteristics of the disease.

After birth

Cleidocranial dysostosis is diagnosed based on physical examination, supported by genetic testing and radiographic findings such as radiographs, X-rays, and CT scans.

A blood test to specifically examine the DNA of the RUNX2 gene can also confirm the diagnosis.

Treatment for cleidocranial dysostosis

Fortunately, there have been many advances and improvements in treatments for cleidocranial dysostosis.

Children with cleidocranial dysostosis can live whole lives with support and treatment to manage the various symptoms and complications.

Managing the orofacial manifestations of cleidocranial dysostosis can be challenging and requires planning.

The execution must be meticulous and performed by a team of oral and craniofacial surgeons, specialized dentists, and orthodontists.

Successful treatment relies on early detection and intervention but usually continues until growth stops.

Some common treatments include:

  • Dental surgery and orthodontic treatments to improve the appearance and chewing ability.
  • Timely treatment and medication for recurrent ear and sinus infections.
  • Protective helmets to prevent head injuries in children with large openings between the skull bones.
  • Calcium and vitamin D supplements for osteoporosis.
  • Craniofacial surgery for functions such as hypertelorism.

Treatment of patients with cleidocranial dysostosis requires a multidisciplinary approach, with team members including dentists, orthodontists, craniofacial surgeons, otolaryngologists, orthopedic surgeons, and geneticists.

After diagnosis, images (X-rays) of the entire skeleton are taken. The patient is referred to a geneticist for evaluation and counseling.

Patients receive audiological (hearing) evaluations.

During childhood, the patient is treated by dental and orthodontic teams to manage supernumerary teeth (extra) and helps the permanent teeth erupt, grow, and position.

The ENT team regularly evaluates patients, and tympanostomy tubes (ear tubes) are placed when necessary.

Bone density is monitored, and patients are treated with calcium and vitamin D.

Some patients, later in childhood, may benefit from orthognathic (jaw) surgery and treatment of the skull defect.

Due to the underdeveloped upper jaw, patients are monitored for respiratory disorders, mainly when sleeping.