Dental researchers map the gene that causes dentinogenesis imperfecta

Mar 16 2005

Dental researchers at The University of Texas Health Science Center are the first in the world to successfully map the gene that causes dentinogenesis imperfecta (DGI) Type III, a disease that affects tooth density and color and over time can cause teeth to wear to the gum line.

Mary MacDougall, Ph.D., professor of pediatric dentistry, associate dean for research and the President’s Council Chair for Excellence in Dental Research, and her research team have identified a rare compound mutation in the dentin sialophosphoprotein (DSPP) gene in a family with DGI-III. Her team includes Juan Dong, M.D., Ph.D., assistant professor of pediatric dentistry; Ting-Ting Gu, M.D., senior research associate in pediatric dentistry; and Leticia Gutierrez Jeffords, D.D.S., a former fellow in pediatric dentistry at the Health Science Center who is now a local pediatric dentist.

Their findings are in the February 2005 issue of the American Journal of Medical Genetics.

“DGI-III is one of the most prevalent dental genetic diseases,” Dr. MacDougall said. “Although it is more prevalent in some parts of the country, throughout the entire United States all types of DGI have an estimated incidence of somewhere between 1-to-6,000 and 1-to-8,000. By identifying the underlying cause of this disease, we can develop strategies for novel clinical treatments using gene therapy."

In labs at the Health Science Center, researchers cloned and characterized the DSPP gene, determined its structure and identified the alteration in a DGI-III affected family.

They are currently working on gene therapy that can be administered to patients with the disease.

“Effective gene therapy would allow us to transport the corrected gene into the developing teeth and replace the nonfunctional gene, thus eliminating the problem,” Dr. MacDougall said.

Dr. MacDougall has been contacted by researchers from throughout the country and from Australia and Europe who are treating patients with this disease and diseases that similarly alter tooth structure and number. The National Institute of Dental and Craniofacial Research of the National Institutes of Health funded the project for nearly $1 million.