Amelogenesis imperfecta

What causes amelogenesis imperfecta?

Amelogenesis imperfecta is caused by mutations in the AMELX , ENAM , and MMP20 genes. These genes provide instructions for making proteins that are essential for normal tooth development. These proteins are involved in the formation of enamel, which is the hard, calcium-rich material that forms the protective outer layer of each tooth. Mutations in any of these genes alter the structure of these proteins or prevent the genes from making any protein at all. As a result, tooth enamel is abnormally thin or soft and may have a yellow or brown color. Teeth with defective enamel are weak and easily damaged.

In some cases, the genetic cause of amelogenesis imperfecta can not been identified. Researchers are working to find mutations in other genes that are responsible for this disorder.

Click on each gene name to learn more about the role it plays in the development of tooth enamel.

Last updated on 05-01-20

How is amelogenesis imperfecta diagnosed?

A dentist can identify and diagnose amelogenesis imperfecta on the basis of the patient's family history and the signs and symptoms present in the affected individual.

Extraoral X-rays (X-rays taken outside the mouth) can reveal the presence of teeth that never erupted or that were absorbed. Intraoral X-rays (X-rays taken inside the mouth) show contrast between the enamel and dentin in cases in which mineralization is affected.

Genetic testing is available for the genes AMELX, ENAM, _and MMP20_. You can visit the Genetic Testing Registry to locate laboratories performing genetic testing for these genes.

The American Academy of Pediatric Dentistry is a source of information to find a pediatric dentist. The National Dental Association can also assist people in locating a dentist.

Last updated on 05-01-20

How is amelogenesis imperfecta inherited?

The different types of amelogenesis imperfecta can have different types of inheritance according to the gene that is altered:

The following types have autosomal dominant inheritance:

  • IA
  • IB
  • IIIA
  • IIIB
  • IV

The types that are inherited in an autosomal recessive manner are:

  • IC
  • IF
  • IG or enamel-renal syndrome type
  • IH
  • IJ
  • IIA1
  • IIA2
  • IIA3
  • IIA4
  • IIA5
  • IIA6

Type 1E is inherited in a dominant pattern linked to the X chromosome.

In autosomal dominant cases, one copy of the altered gene in each cell is sufficient to cause the disorder. Autosomal recessive inheritance means two copies of the gene in each cell have to be altered for the person to have the disease. A condition is considered X-linked if the mutated gene that causes the disorder is located on the X chromosome, one of the two sex chromosomes. In most cases, males with X-linked amelogenesis imperfecta experience more severe dental abnormalities than females with this form of this condition.

Last updated on 05-01-20

How might amelogenesis imperfecta be treated?

Treatment depends on the type of amelogenesis imperfecta, the age of the affected person, and the type and severity of enamel abnormality. Treatments include preventative measures, various types of crowns, as well as tooth implants or dentures, orthodontic, peirodontal and restorative treatment. The social and emotional impact of this condition should also be addressed.

Detailed information on the treatment of amelogenesis imperfecta is available from the UNC School of Dentistry.

Last updated on 05-01-20

Management Guidelines

Guideline on Dental Management of Heritable Dental Developmental Anomalies

The Guideline on Dental Management of Heritable Dental Developmental Anomalies is intended to address the diagnosis, principles of management, and objectives of therapy of children with heritable dental developmental anomalies rather than provide specific treatment recommendations. We recommend you discuss this information with your health care provider.

Last updated on 04-27-20

Name: Healthy Smiles, Healthy Children 211 E. Chicago Ave., Suite 1700
Chicago, IL, 60611-2637 , United States
Phone: (312) 337-2169 Fax : (312) 337-6329 Email: Url:
Name: American Academy of Pediatric Dentistry AAPD 211 East Chicago Avenue, Suite 1600
Chicago, IL, 60611-2637,
Phone: (312) 337-2169 Fax : (312) 337-6329 Email: Url:
John Timothy Wright, DDS, MS. Developmental Defects of the Teeth. Reference Link Amelogenesis imperfecta Genetics Home Reference (GHR). May 2015; Reference Link

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