Potential interactions among single nucleotide polymorphisms in bone- and cartilage-related genes in skeletal...

To investigate SNPs in bone- and cartilage-related genes and their interaction in the aetiology of sagittal and vertical skeletal malocclusions.

This study included 143 patients and classified as follows: skeletal class I (n = 77), class II (n = 47) and class III (n = 19); maxillary retrusion (n = 39), protrusion (n = 52) and well-positioned maxilla (n = 52); mandibular retrognathism (n = 50), prognathism (n = 50) and well-positioned mandible (n = 43); normofacial (n = 72), dolichofacial (n = 55) and brachyfacial (n = 16).

Steiner's ANB, SNA, SNB angles and Ricketts' NBa-PtGn angle were measured to determine the skeletal malocclusion and the vertical pattern. Nine SNPs in BMP2, BMP4, SMAD6, RUNX2, WNT3A and WNT11 were genotyped. Chi-squared test was used to compare genotypes among the groups. Multifactor dimensionality reduction (MDR) and binary logistic regression analysis, both using gender and age as co-variables, were also used. We performed Bonferroni correction for multiple testing.

Significant associations at P < .05 were observed for SNPs rs1005464 (P = .042) and rs235768 (P = .021) in BMP2 with mandibular retrognathism and for rs59983488 (RUNX2) with maxillary protrusion (P = .04) as well as for rs708111 (WNT3A) with skeletal class III (P = .02; dominant model), rs1533767 (WNT11) with a brachyfacial skeletal pattern (P = .01, OR = 0.10; dominant model) and for rs3934908 (SMAD6) with prognathism (P = .02; recessive model). After the Bonferroni correction, none of the SNPs remained associated. The MDR predicted some interaction for skeletal class II, dolichofacial and brachyfacial phenotypes.

Our results suggest that SNPs in BMP2, BMP4, SMAD6, RUNX2, WNT3A and WNT11 could be involved in the aetiology of sagittal and vertical malocclusions.