Although the failure of some permanent teeth to develop is a common genetic anomaly, an orthodontic resident from the University of Texas–Houston Dental Branch, heeding a professor's directive to look for patterns of missing teeth in patients, found a 12-year-old boy missing 14 of his pearly whites. This astute clinical observation set in motion a research effort by investigators at the University of Texas–Houston and Baylor College of Medicine and funded by the National Institute of Dental and Craniofacial Research that ultimately led to the cause: a mutation in a gene called PAX9 (Nat Genet. 2000;24:18-19).
Stephenson J. The Case of the Missing Molars. JAMA. 2000;283(7):875. doi:10.1001/jama.283.7.875