IRF6基因rs2235371位点多态性与非综合征性唇裂伴或不伴腭裂的相关性研究

目的 探讨干扰素调节因子6 (interferon regulatory factor 6,IRF6)基因rs2235371位点820G＞A单核苷酸多态性与非综合征性唇裂伴或不伴腭裂(nonsyndromic cleft lip with or without cleft palate,NSCL士P)的相关性.方法 收集106例患者及其父母以及129名对照及其父母的核心家庭标本,用聚合酶链反应-限制性片段长度多态性的方法进行IRF6基因rs2235371位点单核苷酸多态性检测;用人群关联研究、传递不平衡检验(transmission disequilibrium test,TDT)、单倍型相对风险率(haplotype-based haplotype relative risk,HHRR)、家系为基础的关联检验(family-based association tests,FBAT)等方法进行统计分析.结果 病例组与对照组相比,子代的基因型分布差异无统计学意义(P＞0.05),而等位基因频率比较差异有统计学意义(P＜0.05);母亲组基因型分布差异有统计学意义(P＜0.05);按唇腭裂类型分类后,单纯唇裂组子代基因型分布和等位基因的频率与对照组相比差异均有统计学意义(P＜0.05);而唇腭裂组基因型分布和等位基因频率差异均无统计学意义(P＞0.05).传递不平衡检验提示,rs2235371位点的G等位基因在NSCL±P核心家庭中存在传递不平衡(x2=5.56,P=0.024).HHRR检验x2=5.115,P=0.024,OR=1.674,95％CI:1.069～2.621;FBAT检验Z=2.218,P=0.027.结论 在中国北方人群中IRF6基因rs2235371位点突变与非综合征性唇腭裂存在关联.     

Contribution of variants in and near the IRF6 gene to the risk of nonsyndromic cleft lip with or without cleft palate in a Malay population

Several studies have shown evidence for the contribution of interferon regulatory factor 6 (IRF6) variants to the risk of nonsyndromic oral clefts in Asians; however, this has not included the Malay population. The current study attempts to address this research gap using allele and haplotype transmission disequilibrium analyses. The results showed a strong transmission distortion for multiple haplotypes to patients with nonsyndromic cleft lip with or without cleft palate. Haplotypes carrying the 243 bp allele of D1S2136 and common alleles at the rs861019 and rs2235371 were over‐transmitted to patients. By contrast, haplotypes consisting of the 251 bp allele of D1S2136 and the rare allele at rs2235371 were more under‐transmitted. Furthermore, several variants and haplotypes showed excess maternal transmission, but none of them attained statistical significance in maternal relative risk analyses. In contrast, a significant child genotype effect was observed for several haplotypes, indicating fetal genotype could be the major genetic contribution rather than maternal genotype. The present study therefore further supports a role for IRF6 variants in clefting in this Southeast Asian population. Overall, Asian genetic backgrounds are most likely more susceptible to the haploinsufficiency of IRF6 variants. These variants may contribute to the condition either themselves, or they may be in linkage disequilibrium with other casual variants. © 2011 Wiley‐Liss, Inc.     

Genetic evidence for the role of loci at 19q13 in cleft lip and palate

Background

Clefts of the lip and palate are common birth defects, affecting approximately 1 in 700 births worldwide. The aetiology of clefting is complex, with multiple genetic and environmental influences.

Methods

Genotype based linkage disequilibrium analysis was conducted using the family based association test (FBAT) and the likelihood ratio test (LRT). We also carried out direct sequencing of the PVR and PVRL2 candidate genes based on their homology to PVRL1, a gene shown previously to cause Margarita Island clefting. Participants included 434 patients with cleft lip with or without cleft palate or cleft palate only and their mothers from eight countries in South America, 205 nuclear triads (father‐mother‐affected child) from Iowa, 541 nuclear triads from Denmark, and 100 patients with cleft lip and palate from the Philippines.

Results

An allelic variant in the PVR gene showed statistically significant association with both South American and Iowa populations (p = 0.0007 and p = 0.0009, respectively). Direct sequencing of PVR and PVRL2 yielded 26 variants, including two rare amino acid changes, one in each gene, which were not seen in controls.

Conclusions

We found an association between a common variant in a gene at 19q and isolated clefting in two heterogeneous populations. However, it is unclear from our data if rare variants in PVR and PVRL2 are sufficient to cause clefting in isolation.     

Analysis of genomewide association signals for nonsyndromic cleft lip/palate in a Kenya African Cohort

Nonsyndromic cleft lip with or without cleft palate is a common birth defect with a wide range of prevalence among different populations, apparently highest in Asians and Amerindians and lowest in Africans. Recent genomewide association studies of European-derived and Asian populations have identified six confirmed loci for this phenotype: 1p22.1, 1q32.2 (IRF6), 8q24, 10q25.3, 17q22, and 20q12. However, there have thus far been no studies of these loci in African patients with nonsyndromic cleft lip with or without cleft palate. We carried out association analysis of SNPs in these six candidate chromosomal regions in 128 nonsyndromic cleft lip with or without cleft palate cases and 105 controls from the Rift Valley of Kenya. We observed no apparent association of this phenotype with any of these SNPs, though there was strong statistical power only for 8q24. These results indicate that at least the 8q24 locus does not play a major role in the pathogenesis of nonsyndromic cleft lip with or without cleft palate in east Africa, supporting locus heterogeneity for susceptibility to this phenotype among different major populations of the world.     

2p24.2 (rs7552) is a susceptibility locus for nonsyndromic cleft lip with or without cleft palate in the Brazilian population

The population of Brazil is highly admixed, with each individual showing variable levels of Amerindian, European and African ancestry, which may interfere in the genetic susceptibility of known risk loci to nonsyndromic cleft lip with or without cleft palate (NSCL±P). Here, we investigated 5 reported genome‐wide loci for NSCL±P in an ancestry‐structured case‐control study containing 1697 Brazilian participants (831 NSCL±P and 866 healthy controls). SNPs rs7552 in 2q24.2, rs8049367 in 16p13.3, rs1880646, rs7406226, rs9891446 in 17p13, rs1588366 in 17q23.2 and rs73039426 in 19q13.11 were genotyped using TaqMan allelic discrimination assays and genomic ancestry was estimated using a panel of 40 biallelic short insertion/deletion polymorphic markers informative of the Brazilian population. Logistic regression analysis of the single‐markers revealed rs7552 in 2p24.2 as a susceptibility risk marker for NSCL±P, yielding an odds ratio (OR) of 1.71 (95% confidence interval (CI): 1.31‐2.24, P = 9 × 10^?6) in the homozygous state. Several SNP‐SNP interactions containing rs7552 reached significance after adjustment for multiple tests (both Bonferroni assumption and 1000 permutation test), with the most significant interaction involving the 3‐loci among rs7552, rs9891446 and rs73039426 (P = 6.1 × 10^?9 and p_{1000 permutation} = 0.001). Our study is the first to support the association of rs7552 in 2p24.2 with NSCL±P in the highly admixed Brazilian population.     

Genomic screening identifies novel linkages and provides further evidence for a role of MYH9 in nonsyndromic cleft lip and palate

Nonsyndromic cleft lip with or without cleft palate (NSCLP) is a common birth anomaly that requires prolonged multidisciplinary rehabilitation. Although variation in several genes has been identified as contributing to NSCLP, most of the genetic susceptibility loci have yet to be defined. To identify additional contributory genes, a high-throughput genomic scan was performed using the Illumina Linkage IVb Panel platform. We genotyped 6008 SNPs in nine non-Hispanic white NSCLP multiplex families and a single large African-American NSCLP multiplex family. Fourteen chromosomal regions were identified with LOD>1.5, including six regions not previously reported. Analysis of the data from the African-American and non-Hispanic white families revealed two likely chromosomal regions: 8q21.3-24.12 and 22q12.2-12.3 with LOD scores of 2.98 and 2.66, respectively. On the basis of biological function, syndecan 2 (SDC2) and growth differentiation factor 6 (GDF6) in 8q21.3-24.12 and myosin heavy-chain 9, non-muscle (MYH9) in 22q12.2-12.3 were selected as candidate genes. Association analyses from these genes yielded marginally significant P-values for SNPs in SDC2 and GDF6 (0.01相似文献   

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

目的 研究蛋氨酸合酶基因(methionine synthase,MS)A2756G位点多态性与非综合征型唇腭裂(nonsyndromic cleft lip with or without cleft palate,NSCL/P)的关联性.方法 采用PCR-限制性片段长度多态性技术检测97个NSCL/P病例组核心家庭和104个对照家庭的MS基因A2756G位点的多态性;用人群关联研究分析、病例组核心家庭的传递不平衡检测(transmission disequilibrium test,TDT)、单体型的相对危险度分析(haplotype-based haplotype relative risk,HHRR)、家庭为基础的关联研究(family-based association tests,FBAT)等统计分析.结果 子代、父亲、母亲病例组和对照组之间基因型和等位基因的分布差异均无统计学意义(P>0.05);本研究中在子代和母亲组中未检出GG基因型,AG基因型相对于AA基因型的比值比OR和95%CI分别为子代1.78(0.74～4.34)、父亲0.80(0.36～1.79)、母亲1.26(0.54～2.93),G相对于A基因的OR和95%CI分别为子代1.70(0.78～3.73)、父亲0.88(0.49～1.75)、母亲1.23(0.59～2.60),携带有突变基因G并不能增加患NSCL/P的危险.病例组核心家庭分析,TDT分析χ2=0.034,P>0.05;HHRR分析χ2=0.03,P>0.05;FBAT分析Z=0.186,P>0.05.结论 结果未显示出MS基因A2756G位点多态性和NSCL/P发生的相关性,还待进一步研究.     

西北地区人群JAG2基因多态性与非综合征性唇腭裂的相关性研究

目的探讨JAG2基因多态性与西北地区人群非综合征性唇腭裂(nonsyndromic cleft lip with or without cleft palate,NSCLP)的相关性。方法采用病例-对照研究方法,选取NSCLP患者301例,正常对照304人,采用iMLDR™基因分型技术对JAG2基因的3个单核苷酸多态性(single nucleotide polymorphism,SNP)位点[rs741859(T/C)、rs11621316(A/G)以及rs1057744(C/T)]进行分型,比较其等位基因、基因型及所构建的单倍型在两组人群中的分布差异。结果rs741859位点等位基因C和T在NSCLP组和对照组中的分布差异有统计学意义。rs741859位点CT基因型可将NSCLP的患病风险显著降低至65%(P<0.05),将唇裂伴或不伴腭裂(cleft lip with or without cleft palate,CL/P)的患病风险降低至62%(P<0.05);而rs11621316、rs1057744处于同一连锁不平衡(linkage disequilibrium,LD)区域,连锁程度较高(r2>0.8),其基因型、等位基因在两组中的分布差异无统计学意义(P>0.05)。结论JAG2基因rs741859位点CT基因型可能是中国西北人群NSCLP的保护性基因型。     

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.     

一个非综合征型唇腭裂家系的致病基因鉴定

目的对一个非综合征型唇腭裂家系进行分子遗传学研究,探寻其致病原因。方法对该家系成员进行详细的体格检查和既往史调查,排除综合征型唇腭裂。对该家系1例患儿的基因组DNA进行全外显子组测序及生物信息学分析。筛查到候选致病基因突变位点后,采用Sanger测序对该家系成员及100名健康对照个体进行共分离分析和人群验证分析。结果全外显子组测序及疾病共分离分析显示,该家系患者IRF6基因第4外显子存在c.253A>G(p.Cys85Arg)变异,且该突变未在健康对照个体中检出,文献尚未见报道。结论IRF6基因第4外显子c.253A>G错义变异是导致该家系发病的原因。     

Popliteal pterygium syndrome: a clinical study of three families and report of linkage to the Van der Woude syndrome locus on 1q32

Popliteal pterygium syndrome (PPS) is a rare autosomal dominant disorder, thought to occur with an incidence of approximately 1 in 300 000 live births. The main clinical manifestations are popliteal webbing, cleft lip, cleft palate, lower lip pits, syndactyly, and genital and nail anomalies. This report describes the clinical features in two families with PPS and one isolated case, showing the range of anomalies found both within and between the families. PPS has some features in common with Van der Woude syndrome (VWS), also inherited as an autosomal dominant condition, with cleft lip/palate and, more distinctively, lower lip pits. Although the gene for VWS has not yet been identified, it has been localised to within 1.6 cM in the region 1q32-41. To determine whether PPS and VWS represent allelic forms of the same gene, three families were genotyped for markers flanking and within the critical region. A multipoint lod score of 2.7 was obtained, with no evidence of recombination, supporting the hypothesis that these two disorders are allelic.     

MSX1基因微卫星多态性与非综合征性唇腭裂的相关性研究

目的探讨肌肉片段同源盒1基因（muscle segment homeobox1,MSX1）与湖南汉族非综合征性唇腭裂（nonsydromic cleft lip and patate,NSCLP）的相关性。方法以MSX1基因内含子区的（CA）n微卫星作为遗传标记,对湖南汉族129例NSCLP患儿和108名正常儿童采用聚合酶链反应-变性聚丙烯酰胺凝胶基因分型技术进行基因分型,并经测序确定片段长度,应用病例对照研究进行相关性分析。结果湖南汉族人群MSX1基因（CA）n等位基因分布符合Hardy-Weinberg平衡,杂合率及多态信息量均为0.50;CA4等位基因频率在唇裂伴或不伴腭裂组及单纯性腭裂组高于对照组,CA4,4基因型频率在唇裂伴或不伴腭裂组和单纯性腭裂组高于对照组,差异均有统计学意义（均P〈0.05）。结论MSX1基因内（CA）n微卫星是多态性较好的遗传标记;MSX1基因可能与湖南汉族人群NSCLP发病相关。     

经手术和语音康复后非综合征型唇腭裂儿童静息态脑功能改变的磁共振特征

目的：探讨非综合征型唇腭裂（NSCLP）患儿在外科修复术和语音治疗康复后静息状态脑功能模式。方法：选取北京儿童医院和北京口腔医院就诊的28例NSCLP儿童和28例性别和年龄相匹配的健康者（对照组）,进行3DT1和静息态功能性磁共振数据采集。使用DPARSFA软件进行预处理并计算低频振幅（ALFF）和局部一致性（ReHo）,采用双样本t检验评价组间差异（TFCE校正, P<0.05）。对于有显著性差异脑区的静息态脑功能参数与汉语语言清晰度量表（CLCDS）评分进行相关性分析。结果：NSCLP患儿左颞中回、左枕中回、右楔叶、右楔前叶、左中央后回、左顶上小叶ALFF值明显降低。与对照组相比,ReHo值降低脑区包括左侧的中央后回、中央前回、顶上小叶、缘上回和旁中央小叶。异常脑区的ALFF值和ReHo值与CLCDS评分无显著性相关。结论：经外科修复手术和语音治疗康复后的NSCLP患儿静息态自发性神经元活动及其协调性仍未达到正常水平,且以优势半球的语言相关脑区异常为主。     

广东地区口面裂患者IRF6基因编码区序列特点分析

目的探讨广东地区口面裂患者干扰素调节因子6（Interferon regulatory factor 6,IRF6）基因编码区序列的特点。方法收集广东籍口面裂患者及部分双亲血样共47例,包括1个Van der Woude综合征（van der Woude syndrome,VWS）患者核心家庭,NSCL/P患者40例,面横裂3例,正中裂3例;同时采取13例正常人血液样本做为对照,所有样本提取DNA后扩增IRF6基因的编码区,并进行序列测定和分析。结果共检测到3个突变位点。其中459G〉T和820G〉A两种突变在正常对照及未患病双亲中均被检出,NSCL/P组与正常对照组之间无差异（P〉0.05）。1234C〉T仅在VWS综合征患者中检出,与国际已报道的致病性突变一致。结论广东地区口面裂患者IRF6基因编码区存在三个突变,其中IRF6基因外显子9的1234C〉T突变可能是广东地区VWS患者的一个致病因素。     

Nasal asymmetry changes during growth and development in 6- to 12-year-old children with repaired unilateral cleft lip and palate: A 3D computed tomography analysis

Repaired unilateral cleft lip and palate (UCLP) is often accompanied by the deformity and asymmetry of the nasal region. Three-dimensional analysis was performed to investigate the relationship between nasal soft- and hard-tissue asymmetries, as well as the changes in nasal asymmetry with age, among children with repaired UCLP (age: 6–12 years). Forty-seven patients were included in this study. Their computed tomography records were retrieved for analysis of the 3D asymmetry of 10 landmarks of the nasal soft and hard tissues. We observed that asymmetry was more severe in nasal hard tissues than in soft tissues, particularly in the sagittal dimension. Compared with patients aged 6–9 years old, patients aged 10 to 12 years old had significantly increased vertical asymmetry at the base of the alar groove (Gbase, p = 0.027) and the lateral point of the piriform aperture (LPA), (p < 0.001). The correlation between the LPA and the alar region was weak to moderate (r = 0.290 to 0.488). In conclusion, we found no evidence of growth and development in nasal hard-tissue asymmetry among 6- to 12-year-old children with repaired UCLP, except for the vertical dimension. Nasal soft tissue exhibited a more preferable symmetry than hard tissue, and this could be attributed to the compensatory growth of nasal soft tissue, particularly in the vertical and sagittal dimensions. The weak to moderate correlations between nasal soft-tissue asymmetry and hard-tissue asymmetry were observed in the three dimensions. Surgeons should consider these factors when repositioning the nasal alar and controlling the size of the nostrils.     

Genetics of cleft lip and/or cleft palate: Association with other common anomalies

Cleft lip and/or cleft palate (CL/P) collectively are well known as being amongst the most common birth defects but we still have difficulty explaining why the majority of cases occur. In general, sporadic cases with no family history may be more related to environmental risks, while the presence of one or more affected relative in the same family strongly suggests that genetic factors are the main contributor. Orofacial clefts can occur in conjunction with other defects (syndromic CL/P) or as an isolated defect (non-syndromic – NSCL/P). CL/P syndromes have been studied intensively and appear to have a stronger genetic aetiology. Here we report on the relationship between syndromic and NSCL/P as a phenotypic spectrum resulting from coding or non-coding mutations respectively. We review certain abnormalities that are most frequently associated with CL/P, including dental, heart, brain, skin and certain types of cancer and examine some of the genes that are involved. We include the outcome of recent NSCL/P GWAS data and we will discuss how the genes at these loci might contribute towards clarifying the genetics of CL/P.     

Cellular and molecular mechanisms in the development of a cleft lip and/or cleft palate; insights from zebrafish (Danio rerio)

Human cleft lip and/or palate (CLP) are immediately recognizable congenital abnormalities of the face. Lip and palate develop from facial primordia through the coordinated activities of ectodermal epithelium and neural crest cells (NCCs) derived from ectomesenchyme tissue. Subtle changes in the regulatory mechanisms of NCC or ectodermal epithelial cells can result in CLP. Genetic and environmental contributions or a combination of both play a significant role in the progression of CLP. Model organisms provide us with a wealth of information in understanding the pathophysiology and genetic etiology of this complex disease. Small teleost, zebrafish (Danio rerio) is one of the popular model in craniofacial developmental biology. The short generation time and large number of optically transparent, easily manipulated embryos increase the value of zebrafish to identify novel candidate genes and gene regulatory networks underlying craniofacial development. In addition, it is widely used to identify the mechanisms of environmental teratogens and in therapeutic drug screening. Here, we discuss the value of zebrafish as a model to understand epithelial and NCC induced ectomesenchymal cell activities during early palate morphogenesis and robustness of the zebrafish in modern research on identifying the genetic and environmental etiological factors of CLP.