Analysis of the recurrence patterns for nonsyndromic cleft lip with or without cleft palate in the families of 3,073 Danish probands

The identification of several putative susceptibility loci for nonsyndromic cleft lip with or without cleft palate (CL ± P) has sparked a renewed interest in the genetics of this condition. However, prior to undertaking linkage studies for complex traits such as CL ± P it is desirable to have some understanding of the number and nature of the loci involved in disease susceptibility. The ability to obtain valid estimates of these parameters is contingent on the availability of family data which are unbiased by factors that distort the true familial recurrence pattern. In an effort to obtain such data, 2 centralized data repositories (the Danish Central Person Registry and the Danish Facial Cleft Database), were linked and used to estimate the risks to first, second, and third-degree relatives of 3,073 CL ± P probands born in Denmark from 1952 to 1987. Analyses of these data excluded single locus and additive multilocus inheritance of CL ± P, and provided evidence that CL ± P is most likely determined by the effects of multiple interacting loci. Under a multiplicative model, no single locus can account for more than a threefold increase in the risk to first-degree relatives of CL ± P probands. These data provide further evidence that nonparametric linkage methods (ex. affected relative pair studies) are likely to represent a more realistic approach for identifying CL ± P susceptibility loci, than are traditional pedigree-based methods. However, at least 100 and more realistically several hundred (300–500) affected sib pairs are likely to be required to detect linkage to CL ± P susceptibility loci. © 1996 Wiley-Liss, Inc.     

Survey of genetic counselors and clinical geneticists regarding recurrence risks for families with nonsyndromic cleft lip with or without cleft palate

Nonsyndromic cleft lip with or without cleft palate (CL/P) is a common congenital malformation affecting about 1/1,000 caucasian infants. Although the familial clustering of CL/P has been studied thoroughly, estimation of recurrence risk for genetic counseling purposes can be difficult. A survey was mailed to 912 board-certified genetic counselors, 542 non-board-certified genetic counselors, and 776 board-certified clinical geneticists to investigate the recurrence risks they would assign to three example families with CL/P. Responses were received from 155 (17%) board-certified genetic counselors, 36 (6.6%) non-board-certified genetic counselors, and 100 (18.5%) board-certified clinical geneticists. No major differences were found in their responses, suggesting that for these three families, geneticists would provide similar estimates of risk, regardless of their amount of experience with oral clefts patients, where they are currently employed, or their board certification status. Am. J. Med. Genet. 79:184–190, 1998. © 1998 Wiley-Liss, Inc.     

广东人群PVRL1的多态性与NSCL/P的相关性分析

目的: 探讨脊髓灰质炎病毒受体相关基因( PVRL1 )的多态性与广东人群中非综合征型唇腭裂(NSCL/P,MIM 119530)的相关性。方法: 应用聚合酶链式反应和直接测序的方法对71例广东人群NSCL/P患者和100个健康志愿者的 PVRL1 exon 2和exon 5的多态性进行检测;应用基质辅助激光解吸电离飞行时间(MALDI-TOF)质谱分析的方法对100例广东人群NSCL/P患者和100个健康志愿者的 PVRL1 α亚型的334、391、1 183位点和β亚型的1082位点进行突变检测。结果: PVRL1 的exon 2和exon 5未发现有突变位点;质谱分析没有发现 PVRL1 α亚型的334、391、1 183位点和β亚型的1 082位点相关的S112A、T131A、G361V、V395M突变。结论: PVRL1 的exon 2、exon 5,α亚型334T>A、391A>T、1 183G>A,及β亚型1 082G>T的突变并不参与所研究的广东人群非综合征型唇腭裂的发生。     

Accumulation of rare coding variants in genes implicated in risk of human cleft lip with or without cleft palate

Cleft lip with/without cleft palate (CLP) is a common craniofacial malformation with complex etiologies, reflecting both genetic and environmental factors. Most of the suspected genetic risk for CLP has yet to be identified. To further classify risk loci and estimate the contribution of rare variants, we sequenced the exons in 49 candidate genes in 323 CLP cases and 211 nonmalformed controls. Our findings indicated that rare, protein‐altering variants displayed markedly higher burdens in CLP cases at relevant loci. First, putative loss‐of‐function mutations (nonsense, frameshift) were significantly enriched among cases: 13 of 323 cases (~4%) harbored such alleles within these 49 genes, versus one such change in controls (p = 0.01). Second, in gene‐level analyses, the burden of rare alleles showed greater case‐association for several genes previously implicated in cleft risk. For example, BHMT displayed a 10‐fold increase in protein‐altering variants in CLP cases (p = .03), including multiple case occurrences of a rare frameshift mutation (K400 fs). Other loci with greater rare, coding allele burdens in cases were in signaling pathways relevant to craniofacial development (WNT9B, BMP4, BMPR1B) as well as the methionine cycle (MTRR). We conclude that rare coding variants may confer risk for isolated CLP.     

山东地区非综合征性唇腭裂患者MTHFR基因C677T的多态性研究

目的探讨山东地区亚甲基四氢叶酸还原酶（MTHFR）基因C677T的多态性与非综合征性唇腭裂（NSCL/P）的关系。方法运用聚合酶链反应-限制性内切酶片段长度多态性分析技术（PCR-RFLP）,对2006年8月至2008年8月曾在齐鲁医院治疗的来自山东地区NSCL/P患儿35例和健康查体的正常儿童51例MTHFR基因的C677T基因型检测分析。结果患者组与对照组的基因型构成比有统计学意义（χ^2=8.770,P=0.0121）。对T分析,计算得到携带T等位基因的儿童患非综合征性唇腭裂的危险性是不携带T等位基因儿童的2.568倍（OR=2.568,95%CI：1.324-4.979）。TT突变纯合子患非综合征性唇腭裂的危险性是非TT纯合子的3.095倍（OR=6.088,95%CI：1.240-7.722）。结论 MTHFRC677T的T等位基因可能是山东地区非综合征性唇腭裂的遗传风险因子。     

山东地区非综合征性唇腭裂患者MTHFR基因C677T的多态性研究

目的探讨山东地区亚甲基四氢叶酸还原酶(MTHFR)基因C677T的多态性与非综合征性唇腭裂(NSCL/P)的关系。方法运用聚合酶链反应-限制性内切酶片段长度多态性分析技术(PCR-RFLP),对2006年8月至2008年8月曾在齐鲁医院治疗的来自山东地区NSCL/P患儿35例和健康查体的正常儿童51例MTHFR基因的C677T基因型检测分析。结果患者组与对照组的基因型构成比有统计学意义(χ2=8.770,P=0.0121)。对T分析,计算得到携带T等位基因的儿童患非综合征性唇腭裂的危险性是不携带T等位基因儿童的2.568倍(OR=2.568,95%CI:1.324-4.979)。TT突变纯合子患非综合征性唇腭裂的危险性是非TT纯合子的3.095倍(OR=6.088,95%CI:1.240-7.722)。结论 MTHFRC677T的T等位基因可能是山东地区非综合征性唇腭裂的遗传风险因子。     

Maternal MTHFR variant forms increase the risk in offspring of isolated nonsyndromic cleft lip with or without cleft palate

The pathogenesis of cleft lip with or without cleft palate (CL/P) is complex; its onset could be due to the interaction of various genetic and environmental factors. Recently MTHFR functional polymorphisms were found to increase the risk of this common malformation; however, this finding is still debated. We investigated 110 sporadic CL/P patients, their parents and 289 unrelated controls for c.665C>T (commonly known as 677C>T; p.Ala222Val) and c.1286A>C (known as 1298A>C; p.Glu429Ala) polymorphism in the MTHFR gene. Transmission disequilibrium test (TDT) showed no distortion in allele transmission. Nevertheless, association studies revealed significant differences in allele frequencies between mothers of CL/P patients and controls. This work supports the hypothesis that a lower MTHFR enzyme activity in pregnant women, mostly related to the c.665C>T variant form, is responsible for a higher risk of having CL/P affected offspring.     

Genetic contribution for non-syndromic cleft lip with or without cleft palate (NS CL/P) in different regions of Brazil and implications for association studies

Non-syndromic cleft lip with or without cleft palate (NS CL/P) is a complex disease in which heritability estimates vary widely depending on the population studied. To evaluate the importance of genetic contribution to NS CL/P in the Brazilian population, we conducted a study with 1,042 families from five different locations (Santarém, Fortaleza, Barbalha, Maceió, and Rio de Janeiro). We also evaluated the role of consanguinity and ethnic background. The proportion of familial cases varied significantly across locations, with the highest values found in Santarém (44%) and the lowest in Maceió (23%). Heritability estimates showed a higher genetic contribution to NS CL/P in Barbalha (85%), followed by Santarém (71%), Rio de Janeiro (70%), Fortaleza (64%), and Maceió (45%). Ancestry was not correlated with the occurrence of NS CL/P or with the variability in heritability. Only in Rio de Janeiro was the coefficient of inbreeding significantly larger in NS CL/P families than in the local population. Recurrence risk for the total sample was approximately 1.5-1.6%, varying according to the location studied (0.6-0.7% in Maceió to 2.2-2.8% in Barbalha). Our findings show that the degree of genetic contribution to NS CL/P varies according to the geographic region studied, and this difference cannot be attributed to consanguinity or ancestry. These findings suggest that Barbalha is a promising region for genetic studies. The data presented here will be useful in interpreting results from molecular analyses and show that care must be taken when pooling samples from different populations for association studies.     

Expression and association data strongly support JARID2 involvement in nonsyndromic cleft lip with or without cleft palate

Nonsyndromic cleft lip with or without cleft palate (CL/P) affects approximately 1 in 1,000 births. Genetic studies have provided evidence for the role of several genes and candidate loci in clefting; however, conflicting results have frequently been obtained and much have to be done to unravel the complex genetics of CL/P. In the present investigation we have focused on the candidate region in 6p23, a region that have been found linked to CL/P in several investigations, in the attempt to find out the susceptibility gene provisionally named OFC1. Gene expression experiments in mice embryo of positional candidate genes revealed that JARID2 was highly and specifically expressed in epithelial cells in merging palatal shelves. A family‐based linkage disequilibrium study confirmed the pivotal role of JARID2 in orofacial development and strongly supports a role for this gene in CL/P etiology (multiallelic haplotype test P=6×10^?5). Understanding the molecular role of JARID2 within facial development may offer additional information to further unravel the complex genetics of CL/P. Hum Mutat 31:1–7, 2010. © 2010 Wiley‐Liss, Inc.     

Maternal reproductive loss and cleft lip with or without cleft palate in human embryos

Recognized spontaneous abortions in previous pregnancies were significantly more frequent in mothers of 87 Japanese embryos with cleft lip with or without cleft plate (CL(P)) than in mothers of normal embryos. The number of prior pregnancies was found to be smaller in mothers of CL(P) embryos with additional defects, suggesting that unrecognized abortions might also occur more frequently in these women. The higher incidence of abortions was associated with more severe forms of CL(P), ie, CL(P) with associated anomalies rather than isolated CL(P), and bilateral rather than unilateral CL. These results are compatible with the “multifactorial two-threshold” model with a lower threshold beyond which the malformation occurs and a higher one beyond which the embryo dies. The present results are in contrast with the reduced spontaneous abortion rates in families of CL(P) probands reported previously. The reduced rates may be due to selection of those families in which CL(P) embryos escaped spontaneous abortion and survived to birth, although the effects of compensatory reproduction or maternal recall bias in postnatal data cannot be ruled out completely.     

Gene/environment causes of cleft lip and/or palate

Craniofacial anomalies, and in particular cleft lip and palate, are major human birth defects with a worldwide frequency of 1 in 700 and substantial clinical impact. A wide range of studies in developmental biology has contributed to a better knowledge of how both genes and environmental exposures impact head organogenesis. Specific causes have now been identified for some forms of cleft lip and palate, and we are at the beginning of a time in which the common nonsyndromic forms may also have specific etiologies identified. Mouse models have an especially important role in disclosing cleft etiologies and providing models for environmental cotriggers or interventions. An overview of the gene-environment contributions to nonsyndromic forms of clefting and their implications for developmental biology and clinical counseling is presented.     

蛋氨酸合酶基因A275 6G位点多态性与非综合征型唇腭裂的关联性研究

Objective To study the association of the A2756G polymorphism of the methionine synthase (MS) gene with nonsyndromie cleft lip with or without cleft palate (NSCL/P) in Chinese. Methods Ninety-seven NSCL/P case-parent triads were selected as the case group. One hundred and four healthy subjects and their biological parents were selected as control group. For all subjects the A2756G polymorphism of the MS gene was examined by PCR-RFLP method. Results There was no statistical difference in genotype and allele frequencies for MS A2756G variants among family members between case group and control group. The GG genotype was not detected in the offsprings and mothers. The odds ratio and confidence interval of genotype AG in offspring, father and mother were 1.78(0.74-4.34), 0.80(0. 36-1.79) and 1.26(0. 54-2.93) respectively. The odds ratio and confidence interval of allele G in offspring, father and mother were 1.70(0.78-3.73), 0. 88(0. 49-1. 75) , and 1.23(0.59-2.60) respectively. The G allele did not increase the risk of NSCL/P. Transmission disequilibrium test (TDT) analysis yielded no evidence of linkage disequilibrium (χ2=0.034,P>0. 05). The results of haplotype-based haplotype relative risk (HHRR) analysis (χ2=0.03,P>0.05) and family-based association tests (FBAT) (Z=0. 186, P> 0.05) failed to show association between the MS A2756G variant and the risk of NSCL/P. Conclusion The A2756G polymorphism of the MS gene was not associated with NSCL/P in Chinese in the present study.     

蛋氨酸合酶基因A275 6G位点多态性与非综合征型唇腭裂的关联性研究

Objective To study the association of the A2756G polymorphism of the methionine synthase (MS) gene with nonsyndromie cleft lip with or without cleft palate (NSCL/P) in Chinese. Methods Ninety-seven NSCL/P case-parent triads were selected as the case group. One hundred and four healthy subjects and their biological parents were selected as control group. For all subjects the A2756G polymorphism of the MS gene was examined by PCR-RFLP method. Results There was no statistical difference in genotype and allele frequencies for MS A2756G variants among family members between case group and control group. The GG genotype was not detected in the offsprings and mothers. The odds ratio and confidence interval of genotype AG in offspring, father and mother were 1.78(0.74-4.34), 0.80(0. 36-1.79) and 1.26(0. 54-2.93) respectively. The odds ratio and confidence interval of allele G in offspring, father and mother were 1.70(0.78-3.73), 0. 88(0. 49-1. 75) , and 1.23(0.59-2.60) respectively. The G allele did not increase the risk of NSCL/P. Transmission disequilibrium test (TDT) analysis yielded no evidence of linkage disequilibrium (χ2=0.034,P>0. 05). The results of haplotype-based haplotype relative risk (HHRR) analysis (χ2=0.03,P>0.05) and family-based association tests (FBAT) (Z=0. 186, P> 0.05) failed to show association between the MS A2756G variant and the risk of NSCL/P. Conclusion The A2756G polymorphism of the MS gene was not associated with NSCL/P in Chinese in the present study.     

蛋氨酸合酶基因A275 6G位点多态性与非综合征型唇腭裂的关联性研究

Objective To study the association of the A2756G polymorphism of the methionine synthase (MS) gene with nonsyndromie cleft lip with or without cleft palate (NSCL/P) in Chinese. Methods Ninety-seven NSCL/P case-parent triads were selected as the case group. One hundred and four healthy subjects and their biological parents were selected as control group. For all subjects the A2756G polymorphism of the MS gene was examined by PCR-RFLP method. Results There was no statistical difference in genotype and allele frequencies for MS A2756G variants among family members between case group and control group. The GG genotype was not detected in the offsprings and mothers. The odds ratio and confidence interval of genotype AG in offspring, father and mother were 1.78(0.74-4.34), 0.80(0. 36-1.79) and 1.26(0. 54-2.93) respectively. The odds ratio and confidence interval of allele G in offspring, father and mother were 1.70(0.78-3.73), 0. 88(0. 49-1. 75) , and 1.23(0.59-2.60) respectively. The G allele did not increase the risk of NSCL/P. Transmission disequilibrium test (TDT) analysis yielded no evidence of linkage disequilibrium (χ2=0.034,P>0. 05). The results of haplotype-based haplotype relative risk (HHRR) analysis (χ2=0.03,P>0.05) and family-based association tests (FBAT) (Z=0. 186, P> 0.05) failed to show association between the MS A2756G variant and the risk of NSCL/P. Conclusion The A2756G polymorphism of the MS gene was not associated with NSCL/P in Chinese in the present study.     

蛋氨酸合酶基因A275 6G位点多态性与非综合征型唇腭裂的关联性研究

Objective To study the association of the A2756G polymorphism of the methionine synthase (MS) gene with nonsyndromie cleft lip with or without cleft palate (NSCL/P) in Chinese. Methods Ninety-seven NSCL/P case-parent triads were selected as the case group. One hundred and four healthy subjects and their biological parents were selected as control group. For all subjects the A2756G polymorphism of the MS gene was examined by PCR-RFLP method. Results There was no statistical difference in genotype and allele frequencies for MS A2756G variants among family members between case group and control group. The GG genotype was not detected in the offsprings and mothers. The odds ratio and confidence interval of genotype AG in offspring, father and mother were 1.78(0.74-4.34), 0.80(0. 36-1.79) and 1.26(0. 54-2.93) respectively. The odds ratio and confidence interval of allele G in offspring, father and mother were 1.70(0.78-3.73), 0. 88(0. 49-1. 75) , and 1.23(0.59-2.60) respectively. The G allele did not increase the risk of NSCL/P. Transmission disequilibrium test (TDT) analysis yielded no evidence of linkage disequilibrium (χ2=0.034,P>0. 05). The results of haplotype-based haplotype relative risk (HHRR) analysis (χ2=0.03,P>0.05) and family-based association tests (FBAT) (Z=0. 186, P> 0.05) failed to show association between the MS A2756G variant and the risk of NSCL/P. Conclusion The A2756G polymorphism of the MS gene was not associated with NSCL/P in Chinese in the present study.