Exploring the association between genetic polymorphisms in FGFR2 and children's facial morphology.

BACKGROUND: Studies on animal models and fibroblast growth factor receptor (FGFR2)-associated craniosynostosis syndromes suggest that FGFR2 plays a crucial role in craniofacial development. Therefore, the present exploratory study aims to investigate the relationship between functional genetic polymorphisms of FGFR2 and variations in facial morphology. METHODS: Frontal and lateral photographs of healthy boys (aged 9 to 14 years) and girls (aged 9 to 13 years), taken before the start of orthodontic treatment, were used for the study. Saliva samples from the patients were also analyzed. Patients with syndromes, skull trauma, or cleft lip and palate were excluded from the study. The measurements and determinations of proportions were performed using the Image J image processing program. DNA was extracted from the saliva samples to investigate seven genetic polymorphisms in FGFR2 using real-time PCR (rs2162540, rs2981578, rs10736303, rs1078806, rs11200014, rs1219648, and rs4752566). ANOVA and t-tests were used to investigate the relationship between the genotypes and the horizontal as well as lateral facial proportions. RESULTS: A total of 102 children (60 boys and 42 girls) were included in the analysis. No significant sex-related differences in relative facial dimensions or angles were observed. FGFR2 polymorphisms were significantly associated with distinct facial parameters. The rs10736303 variant was associated with frontal facial proportions related to the eye and midface region, with larger relative dimensions observed in carriers of the AA genotype compared to the AG genotype. The rs2162540 polymorphism was associated with lateral profile measurements, including the relative vermilion height of the lower lip and the mentolabial angle. In addition, rs11200014 showed a significant association with the mentolabial angle, with larger angles observed in AA genotype carriers. CONCLUSION: This exploratory study suggested that FGFR2 polymorphisms may be involved in specific facial parameters, supporting a role of FGFR2 in facial development.