Unraveling A Genetic Association Between Hypodontia and Epithelial Ovarian Cancer

Objective: Epithelial ovarian cancer (EOC) is difficult to diagnose at early stages due to a lack of effective disease markers.  In a previous study at the University of Kentucky (UK), it was shown that subjects with EOC were 8.1 times more likely to have hypodontia than controls. Mutations in PAX9, MSX1, AXIN2, BARX1 and BARX2 have not explained the genetic association of hypodontia with EOC.  This case control study is designed to investigate whether Single Nucleotide Polymorphisms (SNPs) located within or near the RUNX2 gene are associated with hypodontia. If an association of one or more SNP(s) with hypodontia is identified, the hypodontia-associated SNPs will be  tested in future studies for association with hypodontia and a family history of EOC in young subjects (male and female) or for association of hypodontia and diagnosed EOC in adult women.

Method: Orthodontic patients are currently being recruiting  and classified into two research groups (~80/group): hypodontia patients and controls.  DNA is being collected from patient saliva along with information outlining cancer and dental family histories. RUNX2 SNPs (rs545289, rs1406846, and rs6930053) will be genotyped using Taqman®-based methodology.  A Chi-square analysis will be used to access Hardy-Weinberg equilibrium in the control population and to test for association of each SNP with the two groups (significance at p<0.05).

Result: DNA has been collected from 9 patients with hypodontia and 15 controls. Within this population, hypodontia of maxillary lateral incisors is observed most frequently followed by mandibular 2^nd molars, maxillary 1^st premolars and maxillary 2^nd premolars.  Two hypodontia patients also exhibited one or more pegged-shaped lateral incisors.

Conclusion: The teeth affected by hypodontia in this population are consistent with those previously reported at UK.  Statistical conclusions will be summarized following completion of genotyping.