唇瘘、腭裂及唇裂综合征两个家系的遗传分析

我们在此报道北京地区没有亲缘关系的两个家庭中属于van der woude综合征的常染色体显性遗传病,其临床症状包括下唇近中线处唇瘘(下唇有先天性向下的瘘管)、腭裂、唇裂(具有或不具有腭裂)。这三个临床症状可以同时发生在一个受累个体身上,或任何两个症状出现在一个个体身上。这种人携带了这种致病基因。在我们所报道的家庭中,先证者每人还具有舌系带过短的体征。     

A novel mutation of the IRF6 gene in an Italian family with Van der Woude syndrome

Van der Woude syndrome (VWS) is the most common type of syndromic orofacial cleft, being characterised by variable association of lower lip pits, cleft lip and cleft palate. VWS is transmitted in an autosomal dominant manner, with high penetrance and variable expressivity, and a gene for this disease has been mapped in 1q32-q41. Very recently, mutations of the interferon regulatory factor 6 (IRF6) gene have been found in VWS patients, suggesting that this gene plays an important role in the orofacial development. We report a novel mutation of the IRF6 in an Italian family with six members affected by VWS with different expression. This mutation, the W217X, produces a stop codon within exon 6 of the IRF6 gene, with loss of the SMIR domain of the IRF6 protein.     

van der Woude syndrome in two families in China

We report on two unrelated families from the Beijing area in which the autosomal dominant gene for van der Woude syndrome (VWS) is segregating. The clinical features include paramedian lower lip pits (fistula labii inferioris congenita), cleft palate, and cleft lip with or without cleft palate. All three of the clinical features may occur together in an affected individual, or any two together, or any one as a single feature of an individual who carries the gene. The probands in each of our families also have ankyloglossia. This is the first report of VWS from China.     

Linkage analysis in a large Brazilian family with van der Woude syndrome suggests the existence of a susceptibility locus for cleft palate at 17p11.2-11.1.

van der Woude syndrome (VWS), which has been mapped to 1q32-41, is characterized by pits and/or sinuses of the lower lip, cleft lip/palate (CL/P), cleft palate (CP), bifid uvula, and hypodontia (H). The expression of VWS, which has incomplete penetrance, is highly variable. Both the occurrence of CL/P and CP within the same genealogy and a recurrence risk <40% for CP among descendants with VWS have suggested that the development of clefts in this syndrome is influenced by modifying genes at other loci. To test this hypothesis, we have conducted linkage analysis in a large Brazilian kindred with VWS, considering as affected the individuals with CP, regardless of whether it is associated with other clinical signs of VWS. Our results suggest that a gene at 17p11.2-11.1, together with the VWS gene at 1p32-41, enhances the probability of CP in an individual carrying the two at-risk genes. If this hypothesis is confirmed in other VWS pedigrees, it will represent one of the first examples of a gene, mapped through linkage analysis, which modifies the expression of a major gene. It will also have important implications for genetic counseling, particularly for more accurately predicting recurrence risks of clefts among the offspring of patients with VWS.     

Genetic analysis in families with van der Woude syndrome

We have brought together information on 864 affected individuals in 164 families (including three new pedigrees) reported in the 137 year period since 1845 when Demarquay first described a family with what was later called van der Woude syndrome (VWS). Both types of oral cleft, cleft palate (CP) and cleft lip with or without CP (CLP), segregate in these families together with lower lip pits or fistulae in an autosomal dominant mode with high penetrance estimated to be K = .89 and .99 by different methods. Cleft types (CLP and CP) occur in VWS in the same proportions as in the general non-VWS population, ie, about twice as many cleft-bearing individuals have CLP as have CP. On the other hand, we do not find the usually observed excess of females with CP and excess of males with CLP; in VWS the sex ratios are more nearly equal. Lip pits also are equally distributed between the sexes. Affected males and females are equally likely to transmit VWS. However, there is an excess of less severely affected individuals among transmitters and a deficiency of more severely affected, brought about by a proband bias and differential fecundity. The expression of VWS is significantly modified by the genetic background: More extreme phenotypes in parents tend to produce more extreme expression in their children. For a VWS gene carrier the relative risk of transmitting a cleft is 26.45%; that of transmitting lower lip pits is 23.55%. Three pedigrees of lip pits in the literature show no clefts among a significant number of affected individuals. Control of gene expression in VWS in the three target tissues appears to be independent and separately designated. Mutation rate of the VWS gene is calculated to be 1.8 X 10(-5).     

Genetic linkage studies with cleft lip and palate: report of two family studies

Genetic linkage studies are reported on two families with cleft lip +/- cleft palate. For the first family (LP01) the etiology of the clefting is unknown, and the linkage analyses were done assuming both autosomal dominant and autosomal recessive inheritance. Close linkage is rejected with the Duffy blood group under the dominant model and with four loci (Duffy, Kidd, and ABO blood groups and haptoglobin) under the recessive model. The second family (LP02) is a Mexican-American family segregating the van der Woude syndrome with lip pits. The linkage analyses for this autosomal dominant trait excluded close linkage with seven genetic markers, including three on chromosome one. The maximum lod scores were 0.6 with BF (chromosome 6) and 0.4 with the P blood group, which is not yet mapped.     

Novel mutations in the<Emphasis Type="Italic"> IRF6</Emphasis> gene for Van der Woude syndrome

Van der Woude syndrome (VWS, OMIM 119300) is an autosomal dominant craniofacial disorder characterized by pits of the lower lip, hypodontia, and cleft lip and/or cleft palate. It is the most common form of syndromic orofacial clefting and has very high penetrance with varied expressivity. The disease locus for VWS has been mapped to a 1.6-cM region on 1q32–41 between D1S205 and D1S491. Recently, mutations have been found in the interferon regulatory factor 6 (IRF6) gene in patients with VWS and popliteal pterygium syndrome. To identify novel mutations of IRF6 in VWS patients, we screened four Chinese VWS families in all nine exons and their flanking splice junctions by direct sequencing. We identified three missense mutations and one nonsense mutation in IRF6. Our study further confirmed that IRF6 is essential for craniofacial development.X. Wang and J. Liu contributed equally to this work     

Linkage of Van der Woude syndrome (VWS) to REN and exclusion of the candidate gene TGFB2 from the disease locus in a large pedigree

Van der Woude syndrome (VWS) is an autosomal dominant disorder associated with one or more of the following features: clefting of the primary or secondary palate, hypodontia or lower lip pits. It has been estimated to account for 2% of all cases of cleft lip and palate. VWS is one of the rare disorders in which clefting of the primary and secondary palate may be seen to segregate as components associated with the same gene. Because of its autosomal dominant inheritance, VWS is readily accessable to linkage analysis as a preliminary step in the identification of the molecular abnormality underlying the clefting effect in the primary and secondary palate. A reported linkage between REN and VWS has promoted us to use pHRnX3.6 (REN) and several markers surrounding REN for a linkage analysis in a large Swiss family. In a second step, linkage analysis was performed to study restriction fragment length polymorphisms for the candidate gene TGFB2 and other loci recently mapped to the candidate region 1q32–1q41. Evidence for linkage ( = 0.00, lod score = 3.01) between REN and VWS could be confirmed in this pedigree. TGFB2 demonstrated recombination with the disease locus and is unlikely to be causative in VWS. The results of a multipoint linkage analysis showed that VWS was flanked by D1S65 and TGFB2 at a maximum location score of 20.3.     

Strong evidence of linkage disequilibrium between polymorphisms at the IRF6 locus and nonsyndromic cleft lip with or without cleft palate, in an Italian population

Cleft lip with or without cleft palate (CL/P) is one of the most common birth defects, but its etiology is largely unknown. It is very likely that both genetic and environmental factors contribute to this malformation. Mutations in the gene for interferon regulatory factor 6 (IRF6) have been shown to be the cause of Van der Woude syndrome, a dominant disorder that has CL/P as a common feature. Recently, it has been reported that genetic polymorphisms at the IRF6 locus are associated with nonsyndromic CL/P, with stronger association in Asian and South American populations. We investigated four markers spanning the IRF6 locus, using the transmission/disequilibrium test. A sample of 219 Italian triads of patients and their parents were enrolled in the study. Strong evidence of linkage disequilibrium was found between markers and disease in both single-allele (P=.002 at marker rs2235375) and haplotype (P=.0005) analyses. These findings confirm the contribution of IRF6 in the etiology of nonsyndromic CL/P and strongly support its involvement in populations of European ancestry.     

Confirmation of linkage of Van der Woude syndrome to chromosome 1q32: evidence of association with STR alleles suggests possible unique origin of the disease mutation

Van der Woude syndrome (VWS) is an autosomal dominant craniofacial disorder with high penetrance and variable expression. Its clinical features are variably expressed, but include cleft lip and/or cleft palate, lip pits and hypodontia. All VWS families studied to date map the disease gene to a < 2 cM region of chromosome 1q32, with no evidence of locus heterogeneity. The aim of this study is to refine the localization of the VWS gene and to further assess possible heterogeneity. We analyzed four multiplex VWS families. All available members were clinically assessed and genotyped for 19 short tandem repeat markers on chromosome 1 in the VWS candidate gene region. We performed two-point and multipoint limit of detection (LOD) score analyses using a high penetrance autosomal dominant model. All families showed positive LOD scores without any recombination in the candidate region. The largest two-point LOD score was 5.87. Our assay method for short tandem repeat (STR) markers provided highly accurate size estimation of marker allele fragment sizes, and therefore enabled us to determine the specific alleles segregating with the VWS gene in each of our four families. We observed a striking pattern of STR allele sharing at several closely linked loci among our four Caucasian VWS families recruited at three different locations in the US. These results suggest the possibility of a unique origin for a mutation responsible for many or most cases of VWS.     

Linkage of an autosomal dominant clefting syndrome (Van der Woude) to loci on chromosome Iq

Van der Woude syndrome (VWS) is an autosomal dominant disorder in which affected individuals have one or more of the following manifestations: cleft lip, cleft palate, hypodontia, or paramedian lower-lip pits. VWS is a well-characterized example of a single-gene abnormality that disturbs normal craniofacial morphogenesis. As a first step in identifying genes involved in human development, we used a candidate-gene-and-region approach to look for a linkage to VWS. Six families with 3 or more generations of affected individuals were studied. Evidence for linkage (theta = 0.02, lod score = 9.09) was found between the renin (REN) gene on 1q and VWS. Other linked loci included CR1, D1S58, and D1S53. The genes for laminin B2 (LAMB2), a basement-membrane protein, and for decay-accelerating factor (DAF) were studied as possible candidate genes on 1q. Recombinants between VWS and both LAMB2 and DAF excluded these genes from a causal role in the etiology of VWS for the families studied in this report. Multipoint linkage analysis indicated that the VWS locus was flanked by REN and D1S65 at a lod score of 10.83. This tight linkage with renin and other nearby loci provides a first step in identifying the molecular abnormality underlying this disturbance of human development.     

Linkage analysis of 5 novel van der Woude syndrome kindreds to 1q32-q41 markers further supports locus homogeneity of the disease trait.

van der Woude syndrome (vWS, MIM 119300) is a rare autosomal dominant clefting condition with cardinal features of mucous cysts (lower-lip pits) and clefts to the lip and/or palate. The vWS gene has been assigned to a locus in 1q32-q41 by linkage analysis and physical mapping. We have investigated 5 novel vWS families through probands attended for cleft lip and/or palate repair at the Department of Maxillofacial Surgery of H?pital Trousseau, Paris, in order to tentatively refine the genetic map of the vWS region in 1q32-q41 and possibly identify unlinked pedigrees. Linkage analysis was carried out to 6 microsatellite markers (D1S249, D1S425, D1S491, D1S205, D1S414, D1S425), yielding a maximum cumulative LOD score of Z = 3.27 at theta = 0.00 for D1S245. The innermost four markers were found to be tightly linked to one another, with no evidence for recombination. Our results support linkage of vWS within a region of tightly linked markers and do not favour locus heterogeneity of the disease trait.     

Distinct functions for Bmp signaling in lip and palate fusion in mice

Previous work suggested that cleft lip with or without cleft palate (CL/P) is genetically distinct from isolated cleft secondary palate (CP). Mutations in the Bmp target gene Msx1 in families with both forms of orofacial clefting has implicated Bmp signaling in both pathways. To dissect the function of Bmp signaling in orofacial clefting, we conditionally inactivated the type 1 Bmp receptor Bmpr1a in the facial primordia, using the Nestin cre transgenic line. Nestin cre; Bmpr1a mutants had completely penetrant, bilateral CL/P with arrested tooth formation. The cleft secondary palate of Nestin cre; Bmpr1a mutant embryos was associated with diminished cell proliferation in maxillary process mesenchyme and defective anterior posterior patterning. By contrast, we observed elevated apoptosis in the fusing region of the Nestin cre; Bmpr1a mutant medial nasal process. Moreover, conditional inactivation of the Bmp4 gene using the Nestin cre transgenic line resulted in isolated cleft lip. Our data uncover a Bmp4-Bmpr1a genetic pathway that functions in lip fusion, and reveal that Bmp signaling has distinct roles in lip and palate fusion.     

Microsatellite-based fine mapping of the Van der Woude syndrome locus to an interval of 4.1 cM between D1S245 and D1S414.

Van der Woude syndrome (VWS) is an autosomal dominant craniofacial disorder characterized by lip pits, clefting of the primary or secondary palate, and hypodontia. The gene has been localized, by RFLP-based linkage studies, to region 1q32-41 between D1S65-REN and D1S65-TGFB2. In this study we report the linkage analysis of 15 VWS families, using 18 microsatellite markers. Multipoint linkage analysis places the gene, with significant odds of 2,344:1, in a 4.1-cM interval flanked by D1S245 and D1S414. Two-point linkage analysis demonstrates close linkage of VWS with D1S205 (lod score [Z] = 24.41 at theta = .00) and with D1S491 (Z = 21.23 at theta = .00). The results revise the previous assignment of the VWS locus and show in an integrated map of the region 1q32-42 that the VWS gene resides more distally than previously suggested. When information about heterozygosity of the closely linked marker D1S491 in the affected members of the VWS family with a microdeletion is taken into account, the VWS critical region can be further narrowed, to the 3.6-cM interval between D1S491 and D1S414.     

Epidemiological and genetic study of 200 cases of oral cleft in the Emilia Romagna region of northern Italy

Epidemiological and genetic variables in clefts were analyzed during the years 1978-1986 in a case-control study of congenital malformations in the Emilia Romagna region of northern Italy. Among 150,168 newborns, 200 cases of cleft were detected, yielding a prevalence of 1.33 per 1,000. These clefts consisted of 112 (0.075%) cases of cleft lip with or without cleft palate (CL +/- P) and 88 cases (0.058%) of cleft palate (CP). Coexisting abnormalities were found in 32% of cases. The heritability coefficient of CL +/- P was 0.84. No cluster in time or space could be demonstrated. Epilepsy was the only maternal risk factor found to be correlated with clefts. A predominance of males was found among CL +/- P cases.     

Maternal diseases and isolated orofacial clefts in Hungary

BACKGROUND: Isolated orofacial clefts (OFCs) are likely to be caused by gene-environment interaction; therefore, the objective of the current study was to evaluate the possible association between all maternal diseases during pregnancy and isolated cleft lip with or without cleft palate (CL+/-CP) and posterior cleft palate (PCP) in the offspring. METHODS: The database of the large population-based Hungarian Case-Control Surveillance of Congenital Abnormalities, 1980-1996, was evaluated. The database includes 1374 cases with isolated CL+/- CP and 601 with PCP, plus 38,151 matched population controls (without defects) and 20,868 patient controls with other defects. Data collection was based on prospective medical records, retrospective maternal data via a self-reported questionnaire, and home visits of nonresponding families. RESULTS: An increased risk for isolated CL+/- CP was found for children born to mothers with influenza, common cold, orofacial herpes, and gastroenteritis during pregnancy. Risk for isolated PCP was increased in children of mothers with influenza, sinusitis, and bronchitis. Among chronic maternal diseases, epilepsy and angina pectoris showed a higher prevalence in the mothers of children born with isolated OFCs (cases). CONCLUSIONS: Some maternal diseases are risk factors for the pathogenesis of isolated OFCs. It is worth considering the prevention of possible harmful effects of influenza by vaccination during the expected epidemic period.     

Correlation of susceptibility to 6-aminonicotinamide and hydrocortisone-induced cleft palate

Our previous genome-wide Quantitative Trait Locus (QTL) mapping study using mouse A/J by C57BL/6J recombinant inbred (RI) lines suggested several chromosomal regions contain genes influencing susceptibility to phenytoin (PT)-induced cleft lip with or without cleft palate [CL(P)] and 6-aminonicotinamide (6-AN)-induced isolated cleft palate (CP). Importantly, the same chromosomal regions but different RI parental strain alleles were sometimes implicated in susceptibility to these different kinds of orofacial clefting. Here we report the susceptibility to hydrocortisone (HC)-induced CP in these RI lines. We treated pregnant females with HC and studied the incidence of CP in day 17 fetuses. RI lines showed highly correlated responses to HC and 6-AN. The A/J parental line and five RI lines showed very high levels of clefting in response to both of these teratogens. The C57BL/6J parental line and five other RI lines exhibited low incidence of CP for these teratogens. In contrast, there was no significant correlation between incidence of PT-induced CL(P) and HC-induced CP.     

Birth order and oral clefts: a meta analysis

BACKGROUND: There is evidence that late birth order is associated with some complex disorders. For orofacial clefts there is no consensus as to whether increased birth order is associated or not. A meta-analysis of published data on cleft lip or cleft palate (CL/P and CP) was carried out to ascertain whether there is an increased risk for children of high birth order to have an oral cleft. METHODS: All data available with information regarding the frequency of live births and CL/P and CP cases by birth order (1, 2, 3, and 4 or more) were included in the analysis, and the birth order category "1" was considered to be with no risk (OR = 1.0). RESULTS: Children with higher birth order are more likely to have CL/P and CP with odds ratios increasing with birth order to a peak of 3.0 in children birth order "4 or more." Results are not different when isolated and syndromic cases are combined. CONCLUSIONS: CL/P and CP occurrence is correlated with increasing birth order. Further studies, taking into consideration sample size and factors such as income status, race, paternal age, vitamin intake, and social habits, should be done to determine conclusively the association between birth order and oral clefts.     

Anodontia as the sole clinical sign of the ectrodactyly-ectodermal dysplasia-cleft lip (EEC) syndrome

In this report we present another family with oligosymptomatic expression of the EEC syndrome. A mother with complete absence of the permanent teeth had two children with split hand/split foot deformity, as typically seen in the EEC syndrome. Cleft lip/cleft palate was also present in one of them. The great variability in expression of this autosomal dominant syndrome is discussed and the difficulties in genetic counseling are emphasized.     

Epidemiologic Research on Malformations Associated with Cleft Lip and Cleft Palate in Japan

To investigate malformations associated with cleft lip and cleft palate, we conducted surveys at neonatal intensive care units (NICUs) and other non-NICU facilities and to determine whether there are differences among facilities. The regional survey investigated NICU facilities located in Oita Prefecture, including 92 patients with cleft lip and palate (CLP) or cleft palate (CP) that occurred between 2004 and 2013, and the national survey investigated oral surgery, plastic surgery, and obstetrics and gynecology facilities located in Japan, including 16,452 patients with cleft lip (CL), CLP, or CP that occurred since 2000. The incidence per 10,000 births was 4.2, 6.2, and 2.8 for CL, CLP, and CP, respectively, according to the national survey, and 6.3 and 2.9 for CLP and CP, respectively according to the regional survey. These results indicated comparable incidences between the two surveys. In contrast, when the survey results on malformations associated with CLP and CP according to the ICD-10 classification were compared between the national survey conducted at oral surgery or plastic surgery facilities and the regional survey conducted at NICU facilities, the occurrence of associated malformations was 19.8% vs. 41.3% for any types of associated malformation, 6.8% vs. 21.7% for congenital heart disease, and 0.5% vs. 16.3% for chromosomal abnormalities. These results indicated that the incidences of all of these associated malformations were significantly greater in the survey conducted at NICU facilities and similar to the findings from international epidemiological surveys. When comparing the survey conducted at obstetrics facilities vs. NICU facilities, the occurrence of associated malformations was similar results as above. The incidence of CLP and CP was not different between surveys conducted at NICU facilities vs. non-NICU facilities; however, when conducting surveys on associated malformations, it is possible to obtain accurate epidemiological data by investigating NICU facilities where detailed examinations are thoroughly performed.