Single Nucleotide Polymorphisms in COL1A2 Gene and Dental Fluorosis Among 4 and 8-Year-Old Nigerian Children

Aim: To determine the association between single nucleotide polymorphisms (SNPs) within the COL1A2 gene and dental fluorosis among 4- and 8-year-old Nigerian children. Methods: A cross-sectional study was undertaken among 125 four and eight-year-old Nigerian children living in naturally fluoridated areas of Ibadan, Nigeria. Drinking and cooking water samples were collected for F analysis. Buccal mucosa swabs were collected from all children and genomic DNA extracted. Presence or absence of the SNP within the COL1A2 gene was identified by PCR and DNA sequencing for 70 of the participants. Results: The median (minimum, maximum) F concentration of drinking and cooking water were 0.05 (<0.1, 3.0) mg/L and 0.01 (<0.1, 4.0) mg/L respectively. The majority of the study participants (52.9%) were heterozygous for the SNP. There was a statistically significant association between F concentration in drinking water and the occurrence of dental fluorosis (p=0.04). F concentration in drinking water was the only statistically significant predictor of dental fluorosis (p=0.03, OR=3.64(CI=1.11-11.94)) after adjusting for F concentration in cooking water and SNPs. The risk of dental fluorosis tended to increase with the presence of SNPs AA and AC (RR > 1) but this association was not statistically significant. Conclusion: The majority of the study participants had the heterozygote SNP AC genotype of COL1A2 gene. F concentration in drinking water was the only statistically significant predictor of dental fluorosis. The risk of dental fluorosis tended to increase with the presence of SNPs AA and AC (RR > 1) but was not statistically significant.