MSX1 gene polymorphisms and non-syndromic cleft lip with or without palate (NSCL/P): A meta-analysis

Association of MSX1 gene polymorphisms and maxillary lateral incisor agenesis in Non-syndromic cleft lip and/or palate individuals

Background

To investigate the association between MSX1 gene polymorphisms and maxillary lateral incisor agenesis with and without Non Syndromic Cleft lip and palate (NSCL/P) in a South Indian population.

Methods

The study sample was divided into four groups: Group I: Twenty five Cleft lip and palate (NSCL/P) subjects with unilateral/bilateral congenitally missing maxillary lateral incisors, without agenesis of any other permanent teeth, Group II: Twenty five individuals with NSCL/P and a full complement of teeth, Group III: Twenty five non-cleft individuals with unilateral/bilateral congenitally missing maxillary lateral incisors and Control group: Twenty five healthy individuals with normal teeth development and without orofacial defects. MSX1 gene polymorphisms rs12532, rs1042484 and rs11726039 were genotyped by Sanger sequencing method with pre designed primer using ABI 3730 DNA sequencer. Associations were tested using Pearson Chi-square analysis.

Results

The three SNPs, rs12532, rs1042484 and rs11726039 of MSX1 gene exhibited polymorphism. rs12532 was associated with reduced risk of maxillary lateral incisor agenesis in NSCL/P subjects. rs1042484 had significant association with the NSCL/P without maxillary lateral incisor agenesis (full complement of teeth) subjects. rs11726039 showed significant association with NSCL/P with or without maxillary lateral incisor agenesis.

Conclusion

The present study on a South Indian population revealed a significant association between the MSX1 gene polymorphisms and tooth agenesis in NSCL/P subjects. Keywords: MSX1, non syndromic cleft lip and palate, lateral incisor agenesis.

A TAF11 variant contributes to non-syndromic cleft lip only through modulating neural crest cell migration

The NC_000006.12: g.34887814C>G variant in TAF11 was identified as a potential functional variant in a Chinese pedigree including two non-syndromic cleft lip only (NSCLO) cases. Applying Chromatin Immunoprecipitation (ChIP), Electrophoretic mobility shift and super-shift assays, we found that the mutant G allele recruited more STAT1 and STAT3, and increased the expression of TAF11. RNA sequencing, GO and KEGG pathway enrichment, ChIP and dual-luciferase reporter assays revealed that TAF11 downregulated CDH1 and CTNND1 in the cell adhesion pathway by binding to their promoter regions and inhibiting transcriptional activities. Alcian blue staining, time-lapse photography, whole-mount in situ hybridization, phospho-Histone H3 immunofluorescence and TUNEL assays indicated that TAF11 and taf11 overexpression (TAF11OE and taf11OE, respectively) contributed to disturbed migration of cranial neural crest cells and abnormal craniofacial development, as well as increased death and deformity rates in zebrafish. In conclusion, a functionally relevant TAF11 variant, affecting cell migration via modulating CDH1 and CTNND1, was associated with etiology of NSCLO.

Association of rs8670 Polymorphism in the MSX1 Gene With Non-Syndromic Cleft Lip With or Without Cleft Palate in Malay Population

OBJECTIVE

This study aimed to investigate the association between variants present in the MSX1 gene and the risk of developing non-syndromic cleft lip with or without cleft palate (NSCL±P) among individuals of Malay ethnicity in Malaysia.

MATERIALS AND METHODS

This case-control study involved 89 patients with NSCL±P and 100 healthy control subjects. Polymerase chain reaction (PCR) was performed on both exon 1 and exon 2 of the MSX1 gene using four pairs of primers. The amplification products were then subjected to denaturing high-pressure liquid chromatography for initial screening, and the presence of a heteroduplex peak was validated using direct sequencing analysis to detect the single-nucleotide polymorphism.

RESULTS

Five previously known variations (c.-36G>A, p.Ala30Ala, p.Ala34Gly, p.Gly110Gly, and rs8670: C>T) were detected within the MSX1 gene in both NSCL±P patients and controls.A significant association was found between the rs8670: C>T variant and NSCL±P (p = 0.017; OR: 0.368; 95% CI: 0.152 - 0.893), with this particular single-nucleotide polymorphism present in 20% (20) among controls and 7.9% (7) of the NSCL±P cases.

CONCLUSIONS

Our data showed a lower incidence of the rs8670: C>T polymorphism among NSCL±P cases compared to control in this Malay population. However, since this variant is located in the 3'UTR, it could potentially impact the stability of MSX1 mRNA.

Orodental malformations associated with human MSX1 sequence variants

BACKGROUND

MSX1 sequence variants have been known to cause human tooth agenesis (TA) with or without orofacial clefts. However, their roles during the whole processes of tooth development are not fully understood. This study aimed to characterize a 4-membered family with TA carrying a novel MSX1 pathogenic variant and investigate the disease mechanism.

METHODS

The authors conducted whole exome analysis to define the disease-causing sequence variant. They performed microcomputed tomography, morphometric analyses, transcriptome profiling, and molecular characterization to study the affected teeth and the gene variant.

RESULTS

The authors identified an MSX1 pathogenic variant, p.Glu232∗, in affected family members with TA and concomitant orodental anomalies, namely, prominent maxillary labial frenum, central incisor diastema, median maxillary anterior alveolar cleft, tooth fusion, mandibular molar dysmorphology, thin dentin layer, and slender dental roots. MSX1-defective teeth were not apparently microdontic but had thin dentin layers. The mandibular molars showed a homeotic transformation to maxillary counterparts. Genes involved in extracellular matrix organization and dentinogenesis, such as DMP1 and MMP20, were downregulated in dental pulp tissues of MSX1-defective teeth. The p.Glu232∗-truncated MSX1 properly localized to the nucleus but partially lost its transactivation ability. Analyzing reported cases indicated that truncation sequence variants within the homeobox domain of MSX1 caused a more severe TA phenotype than those outside of the homeobox domain, probably due to dominant negativity compared with haploinsufficiency.

CONCLUSIONS

This study provides in vivo evidence that MSX1 contributes to developmental processes of various orodental tissues in humans.

PRACTICAL IMPLICATIONS

Clinically, hypertrophic labial frenum, incisor diastema, and median maxillary anterior alveolar cleft might be considered diagnostic for MSX1-associated TA.

Rs28446116 in PTCH1 is associated with non-syndromic cleft lip with or without palate in the Ningxia population, China

OBJECTIVES

To investigate the association between PTCH1 single nucleotide polymorphism(SNP) and non-syndromic cleft lip with or without palate (NSCL/P) in the Ningxia Hui Autonomous region and predict the function of single nucleotide polymorphism through bioinformatics analysis.

DESIGN

A case-control analysis of 31 single nucleotide polymorphism locus alleles on PTCH1 gene (504 cases and 455 controls) was performed to explore the association between PTCH1 gene polymorphisms and non-syndromic cleft lip with or without palate in Ningxia region. Transcription factors, 3D single nucleotide polymorphism and other related information of single nucleotide polymorphism loci with statistical significance were screened by the case-control experiments, and then analyzed the corresponding transcription factors through the NCBI database.

RESULTS

The case-control study showed that 5 of the 31 single nucleotide polymorphism loci rs357564 (P = 0.0233), rs1805155 (P = 0.0371), rs28446116 (P = 0.0408), rs2282041 (P = 0.0439), rs56119276 (P = 0.0256) had statistically significant differences in allele frequencies between the case and control groups. Bioinformatics analysis revealed that EP300 and RUNX3, among the transcription factors associated with rs28446116, may be associated with the development of non-syndromic cleft lip with or without palate.

CONCLUSION

PTCH1 gene may be associated with the occurrence of non-syndromic cleft lip with or without palate in the Ningxia region, which may be related to the role of EP300 and RUNX3 in the development of cleft lip and palate.

The genetic factors contributing to the risk of cleft lip-cleft palate and their clinical utility

Cleft lip and cleft palate (CL/P) are among the most common congenital malformations in neonates and have syndromic or nonsyndromic forms. Nonsyndromic forms of malformation are being reported to be associated with chromosomal DNA modification by teratogenic exposure and to complex genetic contributions of multiple genes. Syndromic forms are shown to be related to chromosomal aberrations or monogenic diseases. There is a growing body of data illustrating the association of several genes with risk of developing this malformation, including genetic defects in T-box transcription factor-22 (TBX22), interferon regulatory factor-6 (IRF6), and poliovirus receptor-like-1 (PVRL1), responsible for X-linked cleft palate, cleft lip/palate-ectodermal dysplasia syndrome, and Van der Woude and popliteal pterygium syndromes, respectively. Genetic variants in MTR, PCYT1A, ASS1, SLC 25A13, GSTM1, GSTT1, SUMO1 BHMT1, and BHMT2 are being reported to be linked with CL/P risk. The etiology of nonsyndromic CLP is still remained to be unknown, although mutations in candidate genes have been found. Here, we provide an overview about the potential variants to be associated with CL/P for identification of the relative risk of CLP with respect to the basis of genetic background and environmental factors (e.g., dietary factors, alcohol use).

Non-syndromic Cleft Palate: An Overview on Human Genetic and Environmental Risk Factors

The epithelial and mesenchymal cells involved in early embryonic facial development are guided by complex regulatory mechanisms. Any factor perturbing the growth, approach and fusion of the frontonasal and maxillary processes could result in orofacial clefts that represent the most common craniofacial malformations in humans. The rarest and, probably for this reason, the least studied form of cleft involves only the secondary palate, which is posterior to the incisive foramen. The etiology of cleft palate only is multifactorial and involves both genetic and environmental risk factors. The intention of this review is to give the reader an overview of the efforts made by researchers to shed light on the underlying causes of this birth defect. Most of the scientific papers suggesting potential environmental and genetic causes of non-syndromic cleft palate are summarized in this review, including genome-wide association and gene–environment interaction studies.