Gene for tooth enamel could prevent decay.
The tooth fairy could soon have less work on her hands now that a gene needed to make tooth enamel has been identified.
Humans cannot restore tooth enamel when it is damaged because the cells that produce it, called ameloblasts, retire once enamel fully covers mature teeth. Consequently, if the surface of our pearly whites becomes compromised through poor diet or inadequate tooth-brushing, cavities form as bacteria attack layers deeper down.
James O'Sullivanat the University of Manchester, UK, and colleagues, scanned the genomes of four people from the same family who shared a genetic disorder called amelogenesis imperfecta (AI) that leads to weak enamel, and five family members without the condition. They then compared the results with 952 DNA samples from unrelated individuals.
Family members with AI had a mutation on both copies of the gene FAM20A. The four unaffected family members had only one copy of the mutated gene. None of the DNA samples from unrelated people had the mutation.
In mice, a normal version of FAM20A was expressed throughout the teeth, and at particularly high rates when ameleoblasts were maturing, adding weight to the idea that the gene plays a key role in the production of enamel.
Tony Phan, an oral biologist at the University of Western Australia in Crawley, suggests that the protein created by FAM20A may boost the production of enamel by binding to ameloblasts. If so, it may be possible to use the protein to reactivate the enamel-producing cells on damaged teeth to prevent decay taking hold, he says.