OBJECTIVETo analyze the correlation between the phenotype and genotype of tooth agenesis using the tooth agenesis code (TAC) and the traditional descriptor for missing teeth.

METHODSPatients with isolated hypodontia caused by PAX9 or MSX1 mutation reported before May 2007 were enrolled. The teeth missing rate and TAC code were recorded. The missing teeth patterns caused by the two mutations were compared.

RESULTSThe teeth missing rates in each teeth positions were significantly different between maxillary and mandibular except maxillary central incisor, lateral incisor and mandibular canine, first molar (P<0.05, P<0.001). MSX1 gene mutation often led to the loss of maxillary first premolar, maxillary second premolar, and mandibular second premolar, while PAX9 gene mutation often led to the loss of the first, second, and third molars. The results were similar when analyzed either by TAC code analysis or by traditional descriptor.

CONCLUSIONSPAX9 and MSX1 gene mutation can cause different phenotypes of tooth agenesis. The TAC code can be used in the analysis of the correlation between phenotype and genotype of the missing teeth patients.

Anodontia ; genetics ; Genotype ; Humans ; MSX1 Transcription Factor ; genetics ; Mutation ; PAX9 Transcription Factor ; genetics ; Phenotype

The goal of this study was to identify MSX1 gene variants in multiple Chinese families with nonsyndromic oligodontia and analyse the functional influence of these variants. Whole-exome sequencing (WES) and Sanger sequencing were performed to identify the causal gene variants in five families with nonsyndromic oligodontia, and a series of bioinformatics databases were used for variant confirmation and functional prediction. Phenotypic characterization of the members of these families was described, and an in vitro analysis was performed for functional evaluation. Five novel MSX1 heterozygous variants were identified: three missense variants [c.662A>C (p.Q221P), c.670C>T (p.R224C), and c.809C>T (p.S270L)], one nonsense variant [c.364G>T (p.G122*)], and one frameshift variant [c.277delG (p.A93Rfs*67)]. Preliminary in vitro studies demonstrated that the subcellular localization of MSX1 was abnormal with the p.Q221P, p.R224C, p.G122*, and p.A93Rfs*67 variants compared to the wild type. Three variants (p.Q221P, p.G122*, and p.A93Rfs*67) were classified as pathogenic or likely pathogenic, while p.S270L and p.R224C were of uncertain significance in the current data. Moreover, we summarized and analysed the MSX1-related tooth agenesis positions and found that the type and variant locus were not related to the severity of tooth loss. Our results expand the variant spectrum of nonsyndromic oligodontia and provide valuable information for genetic counselling.
Anodontia/genetics* ; Humans ; MSX1 Transcription Factor/genetics* ; Pedigree ; Whole Exome Sequencing

OBJECTIVETo investigate the relationship between muscle segment homeobox gene-1 (MSX1) and the genetic susceptibility of nonsyndromic cleft lip and palate (NSCLP) in Hunan Hans.

METHODSOne microsatellite DNA marker CA repeat in MSX1 intron region was used as genetic marker. The genotypes of 387 members in 129 NSCLP nuclear family trios were analyzed by polymerase chain reaction (PCR) and denaturing polyacrylamide gel electrophoresis. Then transmission disequilibrium test (TDT) and Logistic regression analysis were used to conduct association analysis.

RESULTSTDT analysis confirmed that CA4 allele in CL/P and CPO groups preferentially transmitted to the affected offspring (P = 0.018, P = 0.041). Logistic regression analysis indicated that the recessive model of inheritance was supported, and CA4 itself or CA4 acting as a marker for a disease allele or haplotype was inherited in a recessive fashion (P = 0.009).

CONCLUSIONSMSX1 gene is associated with NSCLP, and MSX1 gene may be directly involved either in the etiology of NSCLP or in linkage disequilibrium with disease-predisposing sites.

Asian Continental Ancestry Group ; Cleft Lip ; genetics ; Cleft Palate ; genetics ; Genetic Markers ; genetics ; Genotype ; Humans ; Linkage Disequilibrium ; Logistic Models ; MSX1 Transcription Factor ; genetics ; Microsatellite Repeats ; genetics ; Pedigree

OBJECTIVETo observe the expression of homeobox gene Msx-1, Msx-2 and Dlx-2 during murine mandibular first molar development.

METHODSThe murine heads or mandibles on embryonic days 11-18 (E11-18) and postnatal day 1-3 (P1-3) were removed, fixed and embedded, 5 micro m serial sections were cut in the coronal plane. Msx-1, Msx-2 and Dlx-2 RNA probes were synthesized by in vitro transcription and labeled with digoxigenin. Msx-1, Msx-2 and Dlx-2 mRNA expression was observed after in situ hybridization.

RESULTSDuring molar development Msx-1 transcripts appeared only in mesenchymal cells, not in epithelial cells. Msx-2 and Dlx-2 both expressed in the epithelial and mesenchymal cells. At the initiation stage of the molar development Msx-2 and Dlx-2 had similar expression. At the bud stage (E13-14) Msx-2 mRNA signaling was intensive in the enamel organ and slight in the dental mesenchyme; Dlx-2 signaling was stronger in the dental papilla. At cap stage (E15-16) Msx-2 showed prominent mRNA signaling in enamel knot and Dlx-2 was maximal in the dental papilla. At the late bell stage (P2-3) Msx-2 transcripts were observed in odontoblasts but not labeled in ameloblasts, and Dlx-2 transcripts appeared in ameloblasts but no labeling was seen in odontoblasts.

CONCLUSIONSMsx-1, Msx-2 and Dlx-2 are expressed in various patterns during murine mandibular first molar development, suggesting they possibly play a role in the interaction between the epithelium and mesenchyme during the molar development.

Animals ; DNA-Binding Proteins ; genetics ; Female ; Gene Expression Regulation, Developmental ; Genes, Homeobox ; Homeodomain Proteins ; genetics ; MSX1 Transcription Factor ; Male ; Mandible ; embryology ; Mice ; Molar ; embryology ; RNA, Messenger ; analysis ; Transcription Factors ; genetics

OBJECTIVETo investigate muscle segment homeobox 1 (MSX1) microsatellite marker distribution and the relationship between MSX1 gene and the genetic susceptibility of nonsyndromic cleft lip and palate (NSCLP) in Hunan Hans.

METHODSOne microsatellite DNA marker CA repeat in MSX1 intron region was used as genetic markers. The genotypes of 129 patients with NSCLP and 108 controls were analyzed by the techniques of polymerase chain reaction (PCR) and denaturing polyacrylamide gel electrophoresis (PAGE). Then case-control study was used to conduct association analysis.

RESULTSThe allele frequencies of the CA repeat microsatellite DNA in Hunan Han normal population were in good agreement with Hardy-Weinberg equilibrium. The polymorphism information content and heterozygosity of CA repeat microsatellite DNA were 0.50 and 0.50 respectively. The allele CA4 frequency in CL/P and CPO group was significantly higher than that of normal controls (P<0.05). The genotype CA4,4 frequency was significantly higher in CL/P and CPO group than that in normal controls (P<0.05).

CONCLUSIONThe microsatellite DNA marker CA repeat in MSX1 is a good genetic marker. MSX1 gene is significantly associated with NSCLP in Hunan Hans.

Base Sequence ; China ; ethnology ; Cleft Lip ; genetics ; Cleft Palate ; genetics ; Ethnic Groups ; genetics ; Gene Frequency ; Genetic Markers ; genetics ; Genetic Predisposition to Disease ; Genotype ; Humans ; MSX1 Transcription Factor ; genetics ; Microsatellite Repeats ; genetics ; Polymorphism, Genetic

The purpose of this study was to investigate the contribution of MSX1 gene to the risk of nonsyndromic cleft lip with or without cleft palate (NS-CL +/- P) in the Korean population. The samples consisted of 142 NS-CL +/- P families (9 with cleft lip, 26 with cleft lip and alveolus, and 107 with cleft lip and palate; 76 trios and 66 dyads). Three single nucleotide polymorphisms (SNPs: rs3821949, rs12532, and rs4464513) were tested for association with NS-CL +/- P case-parent trios using transmission disequilibrium test (TDT) and conditional logistic regression models (CLRMs). Minor allele frequency, heterozygosity, chi2 test for Hardy-Weinberg equilibrium, and pairwise linkage disequilibrium (LD) at each SNP were computed. The family- and haplotype-based association test programs were used to perform allelic and genotypic TDTs for individual SNPs and to fabricate sliding windows of haplotypes. Genotypic odds ratios (GORs) were obtained from CLRMs using R software. Although the family-based TDT indicated a meaningful association for rs3821949 (P = 0.028), the haplotype analysis did not reveal any significant association with rs3821949, rs12532, or rs4464513. The A allele at rs3821949 had a significant increased risk of NS-CL +/- P (GOR, 1.64; 95% confidence interval,1.03-2.63; P = 0.038, additive model). A positive association is suggested between MSX1 rs3821949 and NS-CL +/- P in the Korean population.
Alleles ; Asian Continental Ancestry Group/*genetics ; Cleft Lip/*genetics ; Cleft Palate/*genetics ; Female ; Gene Frequency ; Genotype ; Haplotypes ; Humans ; Linkage Disequilibrium ; Logistic Models ; MSX1 Transcription Factor/*genetics ; Male ; Odds Ratio ; *Polymorphism, Single Nucleotide ; Republic of Korea ; Risk Factors ; Software

OBJECTIVETo detect the MSX1 gene mutation in a Chinese family with oligodontia.

METHODSBlood samples were obtained from seven affected and seven unaffected individuals in the pedigree. All exons and flanking intronic boundaries of the MSX1 gene were amplified with polymerase chain reaction technique and then directly sequenced. The website of bioinformatics was used to predict the effect of the mutation on the function.

RESULTSA splicing mutation (IVS1-2A > G) was found at position -2 near the 3' end of the IVS1 of MSX1, which made a change of the intron 1 splice acceptor site. None of the mutation was found in normal individuals of the family and in 100 unrelated healthy matched control individuals.

CONCLUSIONSIVS1-2A > G was a novel splicing mutation identified in the MSX-1 gene and it might be responsible for nonsyndromic oligodontia in this family.

Adolescent ; Adult ; Asian Continental Ancestry Group ; genetics ; Case-Control Studies ; Child ; Female ; Humans ; MSX1 Transcription Factor ; genetics ; Male ; Middle Aged ; Molecular Sequence Data ; Mutation ; Pedigree ; Tooth Abnormalities ; genetics ; Young Adult

OBJECTIVETo study the relationships between single nucleotide polymorphisms (SNP) of gene msh homebox-1 (MSX-1) (rs3821949, rs12532) and sporadic tooth agenesis by filtering the susceptibility genes in a Jiangsu province population.

METHODSDNA samples were extracted from 198 patients with sporadic tooth agenesis and 207 control subjects. Two MSX-1 gene polymorphisms were genotyped using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) assay. The association between the genetic polymorphism and risk of sporadic tooth agenesis was estimated by chi(2) and logistic regression. The Phase was used to determine the Hardy-Weinberg equilibrium and haplotype association.

RESULTSIn the population, the allele frequency and genotype rates of the SNP rs3821949 were significant different between the patients with sporadic tooth agenesis and normal controls: the A allele frequency in the patients (43.2%) was significantly higher than that in the normal controls (31.4%, P = 0.008), and the AA genotype rate of the patients (14.7%) was significantly higher than that of the controls (12.6%, P = 0.030). However, There were no significant differences in the allele frequency and genotype rates of the SNP rs12532 between the patients with sporadic tooth agenesis and normal controls. Similar results were obtained between the mandibular incisor agenesis cases and controls. The haplotype frequencies of GA (27.9%) were significantly lower in non-mandibular incisor agenesis cases group than that in the control group (37.0%, P = 0.03, OR = 0.51).

CONCLUSIONSThe results show that SNP rs3821949, which is located at 5';near region of the MSX-1 gene, is likely to have an influence on the transcriptional activity of this gene and be associated with sporadic tooth agenesis. The haplotypes constructed with these 2 SNP sites may be linked with the susceptibility gene of non-mandibular incisor agenesis.

Adolescent ; Adult ; Anodontia ; genetics ; Case-Control Studies ; Child ; China ; Female ; Gene Frequency ; Genetic Predisposition to Disease ; Genotype ; Haplotypes ; Humans ; Incisor ; abnormalities ; MSX1 Transcription Factor ; genetics ; Male ; Polymerase Chain Reaction ; Polymorphism, Restriction Fragment Length ; Polymorphism, Single Nucleotide ; Young Adult

OBJECTIVETo investigate the effect of cyclic-tension force on the expression of osteogenesis genes in human periodontal ligament cells (HPDLC).

METHODSHPDLC were cultured on flexible-bottomed plates and subjected to 12% elongation by strain unit at 6 cycles/min (i.e.5-s elongation and 5-s relaxation) for 48 hours in the experimental groups. GEArray Q series Human Osteogenesis Gene Array was used to identify the genes expressed in HPDLC, including growth factors and associated molecules, extracellular matrix and its associated proteins, cell adhesion molecules and housekeeping genes. The changes in the expression of 96 representative transcripts were determined by arrayed cDNA hybridization.

RESULTSAfter application of tension force, 21 genes were significantly upregulated, including 10 growth factors and associated molecules, 10 extracellular matrix and its associated protein and 1 cell adhesion molecules. Two genes were significantly downregulated, including 1 growth factors and associated molecules and 1 cell adhesion molecules.

CONCLUSIONSThe HPDLC can differentiate into osteoblast-like cells by mechanical stretch induction through the activation of some osteogenesis genes.

Cell Adhesion Molecules ; genetics ; metabolism ; Cell Differentiation ; genetics ; Cells, Cultured ; Child ; Gene Expression Profiling ; Gene Expression Regulation ; Humans ; MSX1 Transcription Factor ; genetics ; metabolism ; Male ; Oligonucleotide Array Sequence Analysis ; Osteoblasts ; cytology ; metabolism ; Periodontal Ligament ; cytology ; metabolism ; Receptor, Epidermal Growth Factor ; genetics ; metabolism ; Stress, Mechanical

This study aimed to compare epithelial cells derived from human embryonic stem cells (hESCs) to human ameloblast-lineage cells (ALCs), as a way to determine their potential use as a cell source for ameloblast regeneration. Induced by various concentrations of bone morphogenetic protein 4 (BMP4), retinoic acid (RA) and lithium chloride (LiCl) for 7 days, hESCs adopted cobble-stone epithelial phenotype (hESC-derived epithelial cells (ES-ECs)) and expressed cytokeratin 14. Compared with ALCs and oral epithelial cells (OE), ES-ECs expressed amelogenesis-associated genes similar to ALCs. ES-ECs were compared with human fetal skin epithelium, human fetal oral buccal mucosal epithelial cells and human ALCs for their expression pattern of cytokeratins as well. ALCs had relatively high expression levels of cytokeratin 76, which was also found to be upregulated in ES-ECs. Based on the present study, with the similarity of gene expression with ALCs, ES-ECs are a promising potential cell source for regeneration, which are not available in erupted human teeth for regeneration of enamel.
Ameloblasts ; physiology ; Amelogenesis ; genetics ; Amelogenin ; analysis ; Bone Morphogenetic Protein 4 ; pharmacology ; Cell Culture Techniques ; Cell Differentiation ; drug effects ; Cell Line ; Cell Lineage ; Embryonic Stem Cells ; drug effects ; physiology ; Epithelial Cells ; drug effects ; physiology ; Fibroblast Growth Factor 8 ; analysis ; Hedgehog Proteins ; analysis ; Homeodomain Proteins ; analysis ; Humans ; Keratins ; analysis ; classification ; Lithium Chloride ; pharmacology ; MSX1 Transcription Factor ; analysis ; Mouth Mucosa ; cytology ; Phenotype ; Regeneration ; physiology ; Skin ; cytology ; Transcription Factors ; analysis ; Tretinoin ; pharmacology