ABSTRACT
OBJECTIVE@#To explore whether WNT signaling pathway genes were associated with non-syndromic oral clefts (NSOC) based on haplotypes analyses among 1 008 Chinese NSOC case-parent trios.@*METHODS@#The genome-wide association study (GWAS) data of 806 Chinese non-syndromic cleft lip with or without cleft palate (NSCL/P) trios and 202 Chinese non-syndromic cleft palate (NSCP) case-parent trios were drawn from the International Consortium to Identify Genes and Interactions Controlling Oral Clefts (ICOCs) study GWAS data set, whose Chinese study population were recruited from four provinces in China, namely Taiwan, Shandong, Hubei, and Sichuan provinces. The process of DNA genotyping was conducted by the Center for Inherited Disease Research in the Johns Hopkins University, using Illumina Human610-Quad v.1_B Bead Chip. The method of sliding windows was used to determine the haplotypes for analyses, including 2 SNPs haplotypes and 3 SNPs haplotypes. Haplotypes with a frequency lower than 1% were excluded for further analyses. To further assess the association between haplotypes and NSOC risks, and the transmission disequilibrium test (TDT) was performed. The Bonferroni method was adopted to correct multiple tests in the study, with which the threshold of statistical significance level was set as P < 0.05 divided by the number of tests, e.g P < 3.47×10-4 in the current stu-dy. All the statistical analyses were performed by using plink (v1.07).@*RESULTS@#After quality control, a total of 144 single nucleotide polymorphisms (SNPs) mapped in seven genes in WNT signaling pathway were included for the analyses among the 806 Chinese NSCL/P trios and 202 Chinese NSCP trios. A total of 1 042 haplotypes with frequency higher than 1% were included for NSCL/P analyses and another 1 057 haplotypes with frequency higher than 1% were included for NSCP analyses. Results from the TDT analyses showed that a total of 69 haplotypes were nominally associated with the NSCL/P risk among Chinese (P < 0.05). Another 34 haplotypes showed nominal significant association with the NSCP risk among Chinese (P < 0.05). However, none of these haplotypes reached pre-defined statistical significance level after Bonferroni correction (P>3.47×10-4).@*CONCLUSION@#This study failed to observe any statistically significant associations between haplotypes of seven WNT signaling pathway genes and the risk of NSOC among Chinese. Further studies are warranted to replicate the findings here.
Subject(s)
Humans , Cleft Lip/genetics , Cleft Palate/genetics , Genetic Predisposition to Disease , Genome-Wide Association Study , Genotype , Haplotypes , Polymorphism, Single Nucleotide , Wnt Signaling Pathway/geneticsABSTRACT
Objective: The objective of the study is to determine the association between nonsyndromic oral clefts (OC) in children and ABO, Rh blood groups, lip, and dermatoglyphic patterns of their unaffected parents. Methods: This case–control study was conducted at a tertiary cleft center in Chennai, India, among 240 individuals comprising 80 units (40 cases and controls, respectively). Each unit (triad) was constituted by a child (0–12 years of age) either born with nonsyndromic OC (cases) or with no diagnosed congenital anomaly (control) and their unaffected parents (mother and father). ABO and Rh blood groups, specific lip print, fingerprint pattern, and palmar asymmetry were recorded for each individual. Strength of association of related factors was assessed by multivariable logistic regression reported as adjusted odds ratios and 95% confidence interval. Results: A1-positive blood group was found to be considerably higher among case mothers (14.39 [1.57–32.27]). A higher odds of OCs were observed among case mothers with whorl lip pattern (1.51 [1.16–3.17]) and radial loop pattern in fingers (1.44 [1.09–2.31]) relative to controls. In addition, palmar asymmetry was distinctively higher among case parents compared to controls (P < 0.01). Conclusion: Findings indicate that A1-positive blood group, higher frequency of whorl lip, and radial loop finger patterns in mothers and higher ulnar loop pattern in fathers and palmar asymmetry in both parents increases odds of occurrence of OC among their offspring. These identifiable traits offer potential scope for better service planning among resource-constrained disadvantaged communities in India.
ABSTRACT
OBJECTIVE@#In this study, we used genome-wide association study (GWAS) data to explore whether WNT pathway genes were associated with non-syndromic oral clefts (NSOC) considering gene-gene interaction and gene-environment interaction.@*METHODS@#We conducted the analysis using 806 non-syndromic cleft lip with or without cleft palate (NSCL/P) case-parent trios and 202 non-syndromic cleft palate (NSCP) case-parent trios among Chinese populations selected from an international consortium established for a GWAS of non-syndromic oral clefts. Genotype data and maternal environmental exposures were collected through DNA samples and questionnaires. Conditional Logistic regression models were adopted to explore gene-gene interaction and gene-environment in teraction using trio package in R software. The threshold of significance level was set as 3.47×10-4 using Bonferroni correction.@*RESULTS@#A total of 144 single nucleotide polymorphisms (SNPs) in seven genes passed the quality control process in NSCL/P trios and NSCP trios, respectively. Totally six pairs of SNPs interactions showed statistically significant SNP-SNP interaction (P < 3.47×10-4) after Bonferroni correction, which were rs7618735 (WNT5A) and rs10848543 (WNT5B), rs631948 (WNT11) and rs556874 (WNT5A), and rs631948 (WNT11) and rs472631 (WNT5A) among NSCL/P trios; rs589149 (WNT11) and rs4765834 (WNT5B), rs1402704 (WNT11) and rs358792 (WNT5A), and rs1402704 (WNT11) and rs358793 (WNT5A) among NSCP trios, respectively. In addition, no significant result was found for gene-environment interaction analysis in both of the NSCL/P trios and NSCP trios.@*CONCLUSION@#Though this study failed to detect significant association based on gene-environment interactions of seven WNT pathway genes and the risk of NSOC, WNT pathway genes may influence the risk of NSOC through potential gene-gene interaction.
Subject(s)
Humans , Asian People/genetics , Cleft Lip/genetics , Cleft Palate/genetics , Genome-Wide Association Study , Wnt Signaling Pathway/geneticsABSTRACT
Objective@#Non-syndromic cleft lip with or without cleft palate (NSCL/P) is a common birth defect with its genetic evidence widely explored. This study explored the potential the parent-of-origin (PoO) effect of WNT pathway on the risks of NSCL/P, using a case-parent trio design.@*Methods@#Data on the single nucleotide polymorphism (SNP) of WNT genes were selected from a genome-wide association study (GWAS). A total of 806 Chinese non-syndromic cleft lip patients, with or without cleft palate (NSCL/P) case-parent trios, were gathered from an international consortium. PoO effect of WNT pathway genes and its haplotypes were explored by log-linear models. Additional Wald tests were performed to assess: a) the heterogeneity of PoO effect between different maternal exposures, b) the interaction between PoO effect, c) maternal exposure to environmental tobacco smoke (ETS), and d) multivitamin supplementation during pregnancy. The threshold for statistical significance was adjusted as 3.47×10-4, according to Bonferroni correction.@*Results@#After quality control, a total of 144 SNPs within seven genes were included for analyses, among which 8 SNPs were of potential PoO effect (P<0.05). However, none of them achieved the statistical significance after Bonferroni correction. The haplotype rs4074668-rs12725747 (T-A) on WNT9A showed significant PoO effect, based on the haplotype test for PoO (P=2.74×10-4). In addition, no statistically significant interaction was found in further exploration of this haplotype under environmental exposures as ETS or multivitamin supplementation.@*Conclusions@#Genes in the WNT pathway may influence the NSCL/P risks through the potential PoO effect. Particularly, the haplotype rs4074668-rs12725747 (T-A) on WNT9A presented significant PoO effect on NSCL/P, statistically. From this current study, findings on WNT pathway related risks among the NSCL/P, need to be further validated by independent samples in the future.
ABSTRACT
Non-syndromic oral clefts (NSOC) are among the most common birth defects.The prevalence of NSOC is 1.13-1.30 per 1 000 live births in China,which is higher than those in other major ethnic groups.The etiology of NSOC is complex and heterogeneous,which involves both genetic and environmental risk factors.Although genome-wide association studies have identified a number of risk loci,these loci can only account for a small proportion of the heritability of NSOC.The next-generation sequencing research provides new ideas for further exploring the genetic risk factors of NSOC.This paper summaries the progress in the next-generation sequencing research of NSOC.
ABSTRACT
Non-syndromic oral clefts (NSOC) are among the most common birth defects.The prevalence of NSOC is 1.13-1.30 per 1 000 live births in China,which is higher than those in other major ethnic groups.The etiology of NSOC is complex and heterogeneous,which involves both genetic and environmental risk factors.Although genome-wide association studies have identified a number of risk loci,these loci can only account for a small proportion of the heritability of NSOC.The next-generation sequencing research provides new ideas for further exploring the genetic risk factors of NSOC.This paper summaries the progress in the next-generation sequencing research of NSOC.
ABSTRACT
AbstractNonsyndromic oral clefts are considered a problem of public health in Brazil, presenting a multifactorial etiology that involves genetic and environmental components, such as maternal alcohol consumption. Several candidate genes have been investigated to identify some association with nonsyndromic clefts risk. The epidermal growth factor (EGF) gene is implicated in the normal craniofacial development and its functional +61 A>G polymorphism has been related to cancer susceptibility. It has been suggested that cancer and oral clefts may share the same molecular pathways.Objective Our goal was to evaluate the association between the EGF+61 A>G polymorphism and nonsyndromic oral clefts susceptibility.Material and Methods The case-control study included 218 cleft cases and 253 controls from Brazil. The control group was comprised of individuals without congenital malformations, dental anomalies and family history of clefts. The cleft phenotypes and subphenotypes were determined based on clinical examination. Genomic DNA was extracted from oral mucosa cells obtained by mouthwash. The EGF+61 A>G polymorphism genotype was determined by polymerase chain reaction-restriction fragment length polymorphism.Results We noticed the association between maternal alcohol consumption during pregnancy and cleft occurrence. The A allele and AA genotype were over-represented in cleft cases compared with control group when we considered the bilateral cleft lip with or without cleft palate (CL±P) cases, cleft cases with tooth agenesis and cleft cases presenting family history of cleft, but the differences were not statistically significant. Contradictorily, the G allele was higher in cleft palate only (CP) cases than in control group, showing a borderline p value. Comparing the different cleft phenotypes, we observed statistical differences between CP and CL±P cases. Our data suggest the EGF+61 A>G polymorphism was not related with nonsyndromic oral clefts susceptibility in a Brazilian population, but supported the different genetic background between CL±P and CP. Moreover, we confirmed the potential effect of maternal alcohol intake on cleft risk in our population.
Subject(s)
Humans , Male , Female , Pregnancy , Child , Adolescent , Adult , Young Adult , Cleft Lip/genetics , Cleft Palate/genetics , Epidermal Growth Factor/genetics , Genetic Association Studies , Polymorphism, Restriction Fragment Length , Alcohol Drinking/adverse effects , Brazil , Case-Control Studies , Gene Frequency , Genotype , Polymerase Chain Reaction , Risk Factors , Sex Factors , Smoking/adverse effectsABSTRACT
Nonsyndromic oral clefts (NSOC) are the most common craniofacial birth defects in humans. The etiology of NSOC is complex, involving both genetic and environmental factors. Several genes that play a role in cellular proliferation, differentiation, and apoptosis have been associated with clefting. For example, variations in the homeobox gene family member MSX1, including a CA repeat located within its single intron, may play a role in clefting. The aim of this study was to investigate the association between MSX1 CA repeat polymorphism and NSOC in a Southern Brazilian population using a case-parent triad design. We studied 182 nuclear families with NSOC recruited from the Hospital de Clínicas de Porto Alegre in Southern Brazil. The polymorphic region was amplified by the polymerase chain reaction and analyzed by using an automated sequencer. Among the 182 families studied, four different alleles were observed, at frequencies of 0.057 (175 bp), 0.169 (173 bp), 0.096 (171 bp) and 0.67 (169 bp). A transmission disequilibrium test with a family-based association test (FBAT) software program was used for analysis. FBAT analysis showed overtransmission of the 169 bp allele in NSOC (P=0.0005). These results suggest that the CA repeat polymorphism of the MSX1 gene may play a role in risk of NSOC in populations from Southern Brazil.
Subject(s)
Female , Humans , Male , Cleft Lip/genetics , Cleft Palate/genetics , MSX1 Transcription Factor/genetics , Polymorphism, Genetic/genetics , Alleles , Brazil/epidemiology , Cleft Lip/epidemiology , Cleft Palate/epidemiology , Family , Genes, Homeobox/genetics , Genetic Association Studies/methods , Genetic Predisposition to Disease/epidemiology , Linkage Disequilibrium/genetics , Pedigree , Polymerase Chain Reaction , Risk FactorsABSTRACT
In this report, we have reanalyzed genotyping data in a collection of families from South America based on maternal origin. Genotyping analysis was performed at the Craniofacial Anomalies Research Center at the University of Iowa. These genotypes were derived from genomic DNA samples obtained from blood spots from children born with isolated orofacial clefts in 45 hospitals located in eight countries (Argentina, Bolivia, Brazil, Chile, Ecuador, Paraguay, Uruguay, and Venezuela) collaborating with ECLAMC (Latin American Collaborative Studies of Congenital Malformations) between January 1998 and December 1999. Dried blood samples were sent by regular mail to the Laboratory of Congenital Malformations, Federal University of Rio de Janeiro. Previous findings suggested that mitochondrial haplotype D is more commonly found among cleft cases born in South America. We hypothesized that association of certain genes may depend upon the ethnic origin, as defined by population-specific markers. Therefore, we tested if markers in MTHFR (5,10-methylenetetrahydrofolate reductase) and RFC1 (reduced folate carrier 1) were associated with oral clefts, depending on the maternal origin defined by the mitochondrial haplotype. Transmission distortion of alleles in MTHFR C677T and RFC1 G80A polymorphic variants was tested in 200 mother/affected child pairs taking into consideration maternal origin. RFC1 variation was over-transmitted to children born with cleft lip only (P = 0.017) carrying mitochondrial DNA haplotypes other than haplotype D. Our results provide a new indication that variation in RFC1 may contribute to cleft lip only. Future studies should investigate the association between oral clefts and RFC1 based on more discrete phenotypes.