Familial hypodontia in bronze age Northwest China (1046–771BC)

Objective

This research aimed to report hypodontia cases in a Middle Bronze Age high-tier cemetery in China and test the possible hereditary behind hypodontia by performing kinship tests on those individuals.

Design

In this study, dental anomalies were observed on a human skeletal sample (n = 45) uncovered from Yaoheyuan, China. Ancient DNA analysis was subsequently employed on a subsample of the Yaoheyuan individuals (n = 15), including individuals observed hypodontia and individuals randomly sampled from the cemetery for preliminary investigation on the cemetery demography. Kinship estimation tests (READ, TKGWV2, KIN, and F3 test) were subsequently employed.

Results

The Yaoheyuan elite population had a prevalence (n = 7, 15 %) of tooth agenesis in either the maxilla or mandible, with one to two teeth missing. All missing teeth were incisors, except for one individual missing maxillary second molar. Preliminary ancient DNA results indicate that several kinship groups existed among interred individuals, including those with hypodontia, indicating the hereditary origin of these cases.

Conclusions

The prevalence of hypodontia observed on site is high compared to that in both modern East Asian populations and archaeological samples in the Chinese population. The preliminary kinship analysis suggests a case of familial hypodontia. Ancient DNA analysis should be thoroughly conducted in future studies to understand the genetic markers contributing to those hypodontia cases among the Yaoheyuan individuals.