We conclude that this frameshift mutation in the homeodomain (which plays an essential role in DNA binding) of MSX1 gene is responsible for tooth agenesis in this family.
Although our results are consistent with a lack of association of MSX1rs12532 and the risk of unilateral NSCLP and tooth agenesis, further studies with additional SNPs and a more diverse ethnic cohort are warranted.
In this study, we sought to determine the association between tooth agenesis and DNA sequence variation in the genes MSX1 and PAX9 in an ethnically diverse human population.
These results suggest that the four PAX9 polymorphisms alone have a non-significant main effect on the risk of tooth agenesis but that the AGGC haplotype may have a protective effect associated with a decreased risk of tooth agenesis.
Only few of the probands but several relatives with heterozygous genotypes of WNT10A or EDAR conformed to the common type of non-syndromic tooth agenesis, incisor-premolar hypodontia.
We also report here a novel Glu78FS MSX1 mutation in one family segregating an autosomal dominant form of severe tooth agenesis as an illustration of an evolving theme, i.e., different mutations in the same gene can result in a spectrum of dentofacial phenotypic severity.
Based on previous in vitro experiments on mutation disrupting function of Msx1 homeodomain, we assume that the heterozygous g.8177G>T nonsense mutation affects the amount and function of Msx1 protein and leads to tooth agenesis.
The aim of this study was to search for mutations in the PAX9 and MSX1 genes and to investigate their potential association with the maxillary lateral incisor agenesis (MLIA) phenotype in 12 Portuguese families, a total of 52 individuals, 12 probands and 40 relatives (eight of which had MLIA).
Considering the discrepancy between the high incidence rate of agenesis and the relatively small number of reported causative mutations in PAX9, MSX1 and AXIN2 genes, the genetic contribution to oligodontia probably is much more heterogeneous than expected so far.
Single-nucleotide polymorphisms (SNPs) in PAX9 (rs2295222, rs4904155, rs2073244, rs12881240 and rs4904210) were genotyped, and third molar agenesis and mesiodistal and buccolingual diameters were measured.