Dentinogenesis Imperfecta

What is dentinogenesis imperfecta?

Dentinogenesis imperfecta is a disorder of tooth development. This condition causes teeth to be discoloured (most often a blue-gray or yellow-brown colour) and translucent. Teeth are also weaker than normal, making them prone to rapid wear, breakage, and loss. These problems can affect both primary (baby) teeth and permanent teeth.

Researchers have described three types of dentinogenesis imperfecta with similar dental abnormalities. Type I occurs in people who have osteogenesis imperfecta, a genetic condition in which bones are brittle and easily broken. Dentinogenesis imperfecta type II and type III usually occur in people without other inherited disorders. A few families with type II have progressive hearing loss in addition to dental abnormalities. Type III dentinogenesis imperfecta was first identified in a population from Brandywine, Maryland. Researchers now believe that type II and type III may be the same disorder.

How common is dentinogenesis imperfecta?

Dentinogenesis imperfecta affects an estimated 1 in 6,000 to 8,000 people.

What genes are related to dentinogenesis imperfecta?

Mutations in the DSPP gene cause dentinogenesis imperfecta.

Mutations in the DSPP gene have been identified in people with type II and type III dentinogenesis imperfecta. Type I occurs as part of osteogenesis imperfecta, which is caused by mutations in one of several other genes.

The DSPP gene provides instructions for making three proteins that are essential for normal tooth development. These proteins are involved in the formation of dentin, which is a bone-like substance that makes up the protective middle layer of each tooth. Mutations in the DSPP gene may affect the proteins made by the gene, leading to the production of abnormally soft dentin. Teeth with defective dentin are discoloured, weak, and more likely to decay and break. It remains unclear how DSPP mutations lead to hearing loss in some families with dentinogenesis type II.

How do people inherit dentinogenesis imperfecta?

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 most cases, an affected person has one parent with the condition.

What other names do people use for dentinogenesis imperfecta?

  • DGI
  • Hereditary Opalescent Dentin

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