The tooth fairy has a new job … in autism research. This year, two autism studies have used baby teeth to produce promising early results.
The first, funded by Autism Speaks, uses fallen baby teeth to track a child’s prenatal and infant exposure to chemicals that may contribute the disorder’s development.
In the second, geneticists at the University of California, San Diego, found they could use baby teeth as a painless source of the DNA they need to search for gene changes associated with autism. As a result, children participating in their studies don’t need to undergo stressful blood draws. Instead, their parents simply mail in a fallen baby tooth.
Trailblazing with the tooth fairy
In 2012, Autism Speaks awarded a Suzanne and Bob Wright Trailblazer research grant to epidemiologist Raymond Palmer, of the University of Texas Health Science Center. Dr. Palmer had already developed the first method for analyzing baby teeth for volatile compounds such as pesticides and other potentially toxic pollutants without destroying the chemicals in the process.
“As a result, we can use teeth like an archeological record,” he says. “The enamel of different types of teeth begins to form at different points during prenatal development. In infancy, the enamel continues to absorb chemicals circulating through the baby’s body.”
Dr. Palmer’s Trailblazer award allowed him to complete a pilot study to further test his novel technique as a way to track prenatal and infant exposure to chemicals suspected of contributing to autism’s development.
In the first phase of his research, Dr. Palmer’s team analyzed baby teeth from 71 children diagnosed with autism, from families participating in the Interactive Autism Network (IAN). The researchers looked for measurable levels of acetaminophen (non-aspirin pain killer), bug sprays, weed killers, mothballs and phthalates. Phthalate fumes are given off by a variety of new construction materials, as well as new carpeting, carpet cleaners, wet paint and wood stains.
The researchers compared their results to mothers’ recollections of using various chemicals or being around sources of these chemicals during pregnancy and their child’s infancy. They also asked the mothers about breast feeding and infant formula use and compared this to tooth levels of essential fatty acids known to be important to early brain development.
Early results – not yet published – show an overall good match between tooth analysis and the mothers’ recollections, Dr. Palmer says.
Tooth fairy research: Part II
Armed with this confirmation of his method’s effectiveness, Dr. Palmer’s team hopes to gain major government funding to look for associations between prenatal and early infant chemical exposures and autism risk.
Such increased risk may not be obvious by simply comparing chemical exposures between children who do or do not have autism, Dr. Palmer says. The greatest insights may come from looking at these exposures against the backdrop of genetic differences that may affect vulnerability to potentially toxic chemicals, he explains.
“It’s not necessarily genes or environment,” he says. “It’s likely to be both.”
Tooth fairy genetics: Part II
Meanwhile, the “tooth fairy” geneticists at UCSD have taken a leap forward in their research as well. The team extracted pulp cells from the baby teeth mailed to them. From these they created stem cells that they induced to become neurons (brain nerve cells). In cell culture, these “autistic” neurons showed identifiable differences from normal neurons. In one case, for example, the neurons had abnormal numbers of synapses, or brain cell connections. The researchers were able to correct this abnormality by identifying and replacing the associated gene. (See video below.)
"Taken together, research on baby teeth will inform us about potential causes of autism and who might be most vulnerable," says Dr. Palmer, who is not directly involved in the UCLA study. His team continues to accept baby teeth for their research. To participate, email Heilbrun@uthscsa.edu or call 210-274-4009 for instructions.
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