Objectives: To investigate the relationship between dental fluorosis, polymorphisms in the COL1A2 gene, and serum calciotropic hormone levels.
Methods: We conducted a case-control study among children between 8 and 12 years of age with (n = 75) and without (n = 165) dental fluorosis in two counties in Henan Province, China. The PvuII and RsaI polymorphisms in the COL1A2 gene were genotyped using the PCR-RFLP procedure. Calcitonin and osteocalcin levels in the serum were measured using radioimmunassays.
Results: Children carrying the homozygous genotype PP of COL1A2 PvuII had a significantly increased risk of dental fluorosis (OR =4.85, 95% CI: 1.22-19.32) compared to children carrying the homozygous genotype pp in an endemic fluorosis village (EFV). However, the risk (OR = 1.07, 95% CI: 0.45-2.52) was not elevated when the control population was recruited from a non-endemic fluorosis village. Additionally, fluoride levels in urine and osteocalcin levels in serum were found to be significantly lower in controls from non-endemic villages compared to cases. However, the differences in fluoride and osteocalcin levels were not observed when cases were compared to a control population from endemic fluorosis villages.
Conclusions: This study provides the first evidence of an association between polymorphisms in the COL1A2 gene with dental fluorosis in high fluoride exposed populations. Future studies are needed to confirm the association.