Candidate genes for nonsyndromic cleft lip and palate and maternal cigarette smoking and alcohol consumption: evaluation of genotype-environment interactions from a population-based case-control study of orofacial clefts

Previous studies suggest that the relationship between genes and nonsyndromic cleft lip +/- cleft palate (CLP) or cleft palate only (CP) may be modified by the environment. Using data from a population-based case-control study, we examined allelic variants for three genes, i.e., transforming growth factor alpha (TGFA), transforming growth factor beta 3 (TGFB3), and Msh (Drosophila) homeobox homolog 1 (MSX1), and their interactions with two exposures during pregnancy (maternal cigarette smoking and alcohol consumption) as risk factors for CLP and CP. For each cleft phenotype, risk estimates associated with most allelic variants tended to be near unity. Risk estimates for maternal smoking (> or = 10 cigarettes/day) were significantly elevated for CP and were most elevated among infants with allelic variants at the TGFB3 or MSX1 sites. By comparison, risk estimates for maternal alcohol consumption (> or = 4 drinks/month) were significantly elevated for CLP and were most elevated among infants with allelic variants at the MSX1 site. Our results suggest that development of CLP and CP may be influenced independently by maternal exposures but more significantly by interaction of such exposures and specific allelic variants.     

Nonsyndromic cleft lip with or without cleft palate: evidence of linkage to BCL3 in 17 multigenerational families

Nonsyndromic cleft lip with or without cleft palate (CL/P) is a common craniofacial developmental defect. Recent segregation analyses have suggested that major genes play a role in the etiology of CL/P. Linkage to 22 candidate genes was tested in 11 multigenerational families with CL/P, and 21 of these candidates were excluded. APOC2, 19q13.1, which is linked to the proto-oncogene BCL3, gave suggestive evidence for linkage to CL/P. The study was expanded to include a total of 39 multigenerational CL/P families. Linkage was tested in all families, using an anonymous marker, D19S178, and intragenic markers in BCL3 and APOC2. Linkage was tested under two models, autosomal dominant with reduced penetrance and affecteds only. Homogeneity testing on the two-point data gave evidence of heterogeneity at APOC2 under the affecteds-only model. Both models showed evidence of heterogeneity, with 43% of families linked at zero recombination to BCL3 when marker data from BCL3 and APOC2 were included. A maximum multipoint LOD score of 7.00 at BCL3 was found among the 17 families that had posterior probabilities > = 50% in favor of linkage. The transmission disequilibrium test provided additional evidence for linkage with the 3 allele of BCL3 more often transmitted to affected children. These results suggest that BCL3, or a nearby gene, plays a role in the etiology of CL/P in some families.     

Nonsyndromic cleft lip and palate: no evidence of linkage to HLA or factor 13A

Nonsyndromic cleft lip with or without cleft palate (CLP) is a common craniofacial anomaly, the etiology of which is not known. Population studies have shown that a large proportion of cases occur sporadically. Recently, segregation analyses applied to CLP families have demonstrated that an autosomal dominant/codominant gene(s) may cause clefting in cases. Associations of autosomal dominant CLP and nonsyndromic cleft palate (CP) with HLA and F13A genes on chromosome 6p have been suggested previously. Linkage to these two areas on chromosome 6p were tested in 12 autosomal dominant families with CLP. With a LOD score of -2 or less for exclusion, no evidence of linkage was found to four chromosome 6p markers. Multipoint analysis showed no evidence of a clefting locus in this region spanning 54 cM on chromosome 6p in these CLP families.     

Review: the Michigan cleft twin study

The combined effects of clefting of the lip and/or palate and of their surgical repair have been examined for a cross-sectional sample of 20 MZ and 25 DZ like-sexed twins discordant for clefting, in the age range of 4 to 17 years. The findings of four studies published since 1975 on that sample are explored for the primary, contiguous and pleiotropic effects of clefting. The primary effects on facial structures of repaired cleft lip appear to be minimal. However, for twins with repaired cleft of the palate (with or without cleft of the lip), the maxilla was both deficient antero-posteriorly and was positioned more posteriorly than in their non-cleft co-twins. The maxillary first molars were usually slightly less erupted in the cleft twins than in the non-cleft twins. The cleft palate only twins had larger cranial base angles than their non-cleft co-twins. A contiguous effect of the posteriorly positioned maxilla was a mandibular rotation downward and backward in the cleft palate and bilateral cleft lip and palate groups but not in the unilateral cleft lip and palate group. The slightly larger cranial base angles found for cleft palate only, although contiguous in location, are more likely pleiotropic effect. The pleiotropic effects include a deficit in height and weight for cleft subjects which appears only after puberty. Although the teeth of the cleft twins tended to be smaller than those of the non-cleft twins, the amount was not clinically significant.     

Genetic survey of a group of children with clefting: implications for genetic counseling

A cleft lip, cleft palate, or both are associated with a high frequency of other anomalies. This study gives an inventory of associated anomalies in a consecutive group of children (n = 36) with clefts, referred to a local multidisciplinary cleft team in the Netherlands. In 47.2% of cleft patients associated anomalies were found, allowing diagnosis of provisionally unique syndromes or known entities. In 17 patients family history was positive for clefting; in five patients (13.9%) this influenced the occurrence risks for siblings. Both findings had an effect on genetic counseling of the parents of these children. Additional evidence is provided that all children with clefting should be carefully evaluated by a trained clinician for additional anomalies, including dysmorphic features.     

Evaluation of bone turnover in type I osteoporosis using biochemical markers specific for both bone formation and bone resorption

Multivariate analysis was used to determine which characteristics: sex of the proband, sibling sex, severity of the proband's defect or family history, are the best predictors of recurrence risk among siblings of individuals with non-syndromic cleft lip with or without cleft palate (CL +/- P). Sibling recurrence risks are not significantly related to the sex of the proband. Severity of the proband's defect, classified by the extent of the lip defect (unilateral versus bilateral), was found to be a significant predictor of sibling recurrence, whereas involvement of the palate in the proband's defect was not. A positive family history of clefting (i.e. at least one affected first-degree relative in addition to the proband) and the sex of the sibling were also found to be significant predictors of sibling recurrence. The associations between sibling risk and family history, and sibling risk and bilaterality of the proband's defect appear to be mildly confounded. After adjusting for the effects of family history, the risk to siblings of probands with bilateral lip defects is twice the risk to siblings of probands with unilateral defects (O.R. = 2.00; 95% C.I. 1.25-3.19). A positive family history of clefting increases the risk to siblings by greater than 4-fold (O.R. = 4.49; 95% C.I. 2.74-7.35), after adjusting for the extent of the proband's lip defect. These results provide a rational strategy for identifying subsets of the 'at risk' population which have markedly different recurrence risks. This information is important for genetic counseling, since it allows for more precise estimation of sibling recurrence risks in individual cases.(ABSTRACT TRUNCATED AT 250 WORDS)     

The major locus for multifactorial nonsyndromic cleft lip maps to mouse chromosome 11

Cleft lip with or without cleft palate, CL(P), a common human birth defect, has a genetically complex etiology. An animal model with a similarly complex genetic basis is established in the A/WySn mouse strain, in which 20% of newborns have CL(P). Using a newly created congenic strain, AEJ.A, and SSLP markers, we have mapped a major CL(P)-causing gene derived from the A/WySn strain. This locus, here named clf1 (cleft lip) maps to Chromosome (Chr) 11 to a region having linkage homology with human 17q21-24, supporting reports of association of human CL(P) with the retinoic acid receptor alpha (RARA) locus.     

Complex segregation analysis in a sample of consecutive newborns with cleft lip with or without cleft palate in Italy

The mode of inheritance of cleft lip with or without cleft palate (CL/P) has been extensively investigated, but the results are controversial. We report results of complex segregation analysis performed in the families of 636 consecutive newborns with CL/P registered in the northeast Italy and Emilia Romagna congenital malformation registries to test hypotheses regarding CL/P inheritance. The programs POINTER and COMDS have been used. POINTER could not distinguish between alternative genetic models, and only the hypothesis of no familial transmission could be rejected. COMDS results, after inclusion of the severity parameter, rejected the hypotheses of a single major locus and were consistent with the two-locus model with a major dominant locus and at least one modifier locus.     

Rigid external distraction: its application in cleft maxillary deformities

Patients with severe maxillary hypoplasia secondary to congenital facial clefting present numerous challenging problems for the reconstructive surgeon. Traditional surgical/orthodontic approaches for these patients often fall short of expectations, especially for achieving normal facial aesthetics and proportions. The purpose of this paper is to present our clinical experience and cephalometric results with the use of rigid external distraction for the treatment of patients with severe maxillary deficiency. Eighteen consecutive orofacial cleft patients with severe maxillary hypoplasia were treated with maxillary distraction osteogenesis. Criteria for patient selection included severe maxillary hypoplasia with negative overjet of 8 mm or greater, patients with normal mandibular morphology, and patients with full primary dentition or older. There were 10 unilateral cleft lip and palate patients, 6 bilateral cleft lip and palate patients, and 2 patients with severe congenital facial clefting. A maxillary splint was prepared for each patient, and all patients underwent a high Le Fort I maxillary osteotomy. All surgery was performed on either an outpatient or a 23-hour admission basis. No patient required blood transfusions or intermaxillary fixation. Two types of mechanical distraction were utilized in this series. In group 1 (n = 14), the patients underwent rigid external distraction with an external distraction device. In group 2 (n = 4), patients underwent face mask distraction with elastics. There was no surgical morbidity in any of the patients. For the patients in the rigid external distraction group, the mean effective horizontal advancement of the maxilla was 11.7 mm. All of these patients had correction of their negative overjet. For patients in the face mask distraction group, the results were disappointing. The mean effective advancement of the maxilla in this group was only 5.2 mm. In all face mask distraction patients, the initial maxillary hypoplasia was undercorrected. Maxillary distraction osteogenesis with rigid external distraction permits full correction of the midfacial deficiency, including both the skeletal and soft-tissue deficiencies. Rigid external distraction in patients with severe maxillary hypoplasia allows full correction of the deformity through treatment of the affected region only. It offers the distinct advantage of correcting these severe deformities through a minimal procedure. Rigid external distraction has dramatically improved our treatment results for patients with severe cleft maxillary hypoplasia.     

Development of the residual cleft in the hard palate after velar repair in a 2-stage palatal repair regimen

Delayed closure of the hard palate is believed to improve maxillary growth and facial appearance in cleft lip and palate patients. However, the cleft opening in the hard palate after velar closure might impair speech development. The aim of this investigation was to study the development of the residual cleft in the hard palate after 2-stage palatal repair (TSPR) in children born with complete cleft lip and palate (bilateral [BCLP]; n = 7 or unilateral [UCLP]; n = 22) or isolated cleft palate (CP; n = 9). Moreover, we aimed to investigate whether any morphologic factors before surgery might predict development of the residual cleft. Dental casts obtained prior to velar repair (mean age 7 months) and postoperatively at 1 1/2, 3, 4, 5 and 7 years were analyzed with a Reflex Microscope regarding the width, length and area of the cleft in the hard palate. The palatal cleft varied in size both pre- and postoperatively in all 3 types of cleft patients. The width of the cleft in the UCLP subgroup showed a marked reduction immediately after velar repair, but then, on average, remained stable until final surgical closure of the hard palate. In the BCLP subgroup the initially rather narrow width of the clefts remained unchanged postoperatively. Clefts in the CP subgroup, especially in those with a complete cleft, remained large after veloplasty. In 4 of the UCLP and 2 of the BCLP patients, the cleft width increased gradually. In some other subjects, both in the UCLP and BCLP subgroups, the residual cleft closed functionally with time, but this development could not be foreseen.     

Deficient and delayed primary palatal fusion and mesenchymal bridge formation in cleft lip-liable strains of mice

During mammalian primary palate formation, the facial prominences enlarge around the nasal pit, fuse and then merge to give rise to the tissue of the upper lip and premaxillary region. The mechanisms involved in successful primary palate formation and how they are affected in the cleft lip genotype remain poorly understood. The purpose of this study was to compare morphometrically internal development and growth of the primary palate in five different strains of mice. Two of the strains, BALB/cByJ, and C57BL/6J, have normal primary palate development, and three of the strains, A/J, A/WySn, and CL/Fr, have stable frequencies of cleft lip associated with genotype. In the present study, frequencies of 4, 23, and 24%, respectively, were observed on day 13. For palatal growth analysis, embryos were collected on days 10 and 11, staged by number of tail somites (TS), and the heads were photographed and serially sectioned for measurement of primary palate components. The heights of the epithelial seam and the mesenchyme bridge between the facial prominences were measured on serial sections and areas of contact were calculated. The position or depth of the maxillary prominence was determined from the number of frontal sections from its tip to the rostral end of the nasal fin. Analysis of measurements showed that in cleft lip strains enlargement of the epithelial seam and replacement of epithelia by a mesenchymal bridge were both delayed relative to somite stages. Measurements from day 11 embryos with complete failure of contact were excluded from the growth analyses. The mesenchymal bridge formed at 12--13 TS in noncleft strains, 14 TS in the A/J strains with higher cleft lip frequency, and 15--17 TS in A/WySn and CL/Fr strains with higher cleft lip frequency. Forward growth of the maxillary prominence was highly correlated with the primary palate measurements and mesenchymal bridge formation in all strains. In both cleft and noncleft strains, the primitive choanae open at 18--20 TS and the medial nasal region narrows with advancing embryonic development. As a result, cleft lip-liable strains have a narrower window in development in which a robust mesenchymal bridge must form, thus increasing the liability to cleft lip.     

Age-related decline in female fertility is not due to diminished capacity of the uterus to sustain embryo implantation

Rapp-Hodgkin syndrome and AEC syndrome are two disorders in which ectodermal dysplasia and clefting are associated. Rapp-Hodgkin syndrome is an autosomal dominant condition characterized by cleft lip and palate, peculiar craniofacial features, and ectodermal dysplasia, consisting of abnormalities of teeth, hair, nails and sweating. AEC syndrome manifests the same defects plus ankyloblepharon and a higher frequency of scalp dermatitis. A child affected by ectodermal dysplasia associated with clefting, ankyloblepharon, severe scalp dermatitis, and the characteristic Rapp-Hodgkin facies is reported. The overlap between Rapp-Hodgkin syndrome and AEC syndrome is discussed. Critical review of both disorders suggest that AEC syndrome and Rapp-Hodgkin syndrome represent the same entity.     

Oro-nasal fistula development and velopharyngeal insufficiency following primary cleft palate surgery—an audit of 148 children born between 1985 and 1997

We present an audit of primary cleft palate surgery in our unit including rates of two important post-operative complications.Multidisciplinary audit clinics ran from March 1998 to April 2002 to follow up all local patients with a cleft lip or palate who had undergone primary palatal surgery in our unit. One hundred and forty eight patients were studied. Patient ages at follow-up ranged from 3 years and 10 months to 17 years and 4 months. Two surgeons performed the primary surgery. One hundred and twenty eight Wardill-Kilner and 20 Von Langenbeck repairs were performed.We found a 4.7% rate of oro-nasal fistula development requiring surgical closure, and a 26.4% rate of velopharyngeal insufficiency (VPI) requiring subsequent pharyngoplasty. We noted that the type of cleft involved affected the rate of VPI, 16% of patients with unilateral cleft lip and palate versus 29.2% of patients with a solitary cleft palate requiring secondary surgery.Outcome of surgery was determined by a ‘Cleft Audit Protocol for Speech’ (CAPS) speech therapy assessment at follow-up clinics. Only 14.9% of all patients assessed demonstrated any degree of hypernasality.Our results compare favourably with other recent studies including the Clinical Standards Advisory Group (CSAG) report into treatment of children with cleft lip and palate.     

Plasma integrated concentration of growth hormone after recombinant human growth hormone injection. Implications for determining an optimal dose

The length of the cervical spine in a series of 206 adult males with cleft lip and/or palate and 50 normal controls was measured. The patients were divided into five subgroups according to the type and extent of the cleft. The shortening of the spine was most marked in bilateral cleft lip and palate patients (complete), less marked in unilateral cleft lip and palate patients, and was slight in isolated cleft palate patients. Complete isolated cleft palate and cleft lip was not associated with a shortening of the spine. A shortening of the cervical spine in less extensive types of isolated cleft palate was suggestive of the participation of the spine in their development, while in cleft lip and palate a simultaneous exposure to a teratogenic agent or any other developmental error during early stages of embryogenesis could explain the concomitant occurrence of spine anomalies. Patients with cleft lip and palate associated with a short spine also had a shorter mandibular ramus, which could be suggestive of simultaneous damage to both structures during morphogenesis. This relationship was not demonstrated in isolated cleft palate that developed in later stages of embryogenesis. In these cases a short spine itself could not have impaired the growth potential of the mandible, yet it could have mechanically induced the development of cleft palate. These observations are in agreement with the present state of knowledge on the development of orofacial clefts as shown in experimental animals.     

Two patients with multiple facial clefts including cleft lip and palate

Report of 2 patients with cleft lip and palate and multiple facial clefts are described using the anatomical classification of Tessier. The first patient was severely polymalformed, with heart, vertebral, and facial malformations. He was examined clinically and with an experimental three-dimensional computer reconstruction that identified an association of a classic cleft lip and palate with cleft nos. 4 and 11 on the right side and cleft nos. 3 and 11 on the left. The second patient, a partial form, with cleft lip and palate and cleft nos. 3 and 11 on the right side, also presented with bilateral cleft no. 7, preauricular tags, and an important microgenia. This second patient was operated for the cleft lip using the principles of Millard and Onizuka with a supplementary Z plasty. We comment on the difficulties of delimitation and treatment when the clefts are very close together and the difference in "quality" of the tissues compared with classic cleft lip and palate.     

Trichuris ovis and Trichuris globulosa: morphological, biometrical, and genetic studies

We report a 2-year-old girl with a combination of the ectodermal dysplasia, ectrodactyly, cleft lip/palate (EEC) syndrome, distinctive hair abnormalities, scalp dermatitis and atopic disease. To our knowledge, this is the first report of scalp dermatitis in the EEC syndrome. Distinctive structural hair abnormalities shared by the syndromes of ectodermal dysplasia and clefting are helicotrichia, pili torti et canaliculi, and cuticle defects, all of which were observed in the present case. A high incidence of atopic disease in certain subsets of ectodermal dysplasia has been reported. In our patient this manifested as food-induced exacerbation of atopic dermatitis, associated with positive prick tests and significant levels of circulating specific IgE.     

The effect of dam strain on the craniofacial morphogenesis of CL/Fr mouse fetuses

The embryo transfer technique and cephalometry were used to investigate the effect of dam strain in intrauterine craniofacial growth and the severity of cleft lip and palate (CLP) in a CLP-susceptible CL/Fr strain of embryos. The CL/Fr strain of embryos at early blastocyst stage was transferred to the same dam strain and to the CLP-resistant C57BL dam strain. On the 18th gestational day, each dam was laparotomized to take out the fetuses. The spontaneous incidence of CLP in the fetuses was checked and a cephalometric observation of the craniofacial complex of each fetus was done just after laparotomy. The dorsoventral craniofacial size of the unaffected fetuses and the severity of CLP i the affected ones were compared between both dam strains. The following results were obtained: 1) The overall craniofacial sizes of the unaffected fetuses observed in the CL/Fr dam strain were significantly smaller than those seen in the C57/BL dam strain. Those of the affected fetuses observed in the CL/Fr dam strain were smaller than those seen in the C57BL dam strain although the interstrain difference was not significant. 20 The dam strain had a highly significant effect on the craniofacial size of the unaffected fetuses. 3) The CLP frequency in the CL/Fr dam strain was significantly higher than that in the C57BL dam strain. 4) The severity of CLP in the affected fetuses observed in the CL/Fr dam strain was significantly more serious than that seen in the C57BL dam strain. These results indicated that the CLP-susceptible CL/Fr dam strain retarded the intrauterine craniofacial growth of the fetuses and that the cleft condition in the affected fetuses observed in the CL/Fr dam strain was more seriously affected than that seen in the CLP-resistant C57BL dam strain. Thus, it can be concluded that the effect of the dam strain played an important role in the craniofacial morphogenesis of the CL/Fr strain of mouse fetuses that developed from the embryo transferred to the CL/Fr and C57BL dam strains along with the genotype of embryos.     

Levator veli palatini muscle activity in relation to intraoral air pressure variation in cleft palate subjects

A comparison of the ranges of levator veli palatini EMG activity for speech versus a nonspeech task for subjects with cleft palate was the focus of this study. EMG values are also compared with subjects without cleft palate obtained in a previous study. Hooked-wire electrodes were inserted into the levator muscle of five adult subjects with cleft palate exhibiting mild hypernasality. Intraoral air pressure was measured concurrently. A blowing task was used to determine the subject's operating range for the levator muscle. Both the nonspeech and speech tasks were designed to sample the widest possible ranges of levator EMG activity. It was found that the subjects with cleft palate used a relatively high activation level for the levator muscle during speech, in relation to their total activation range, compared with the subjects without cleft palate. Implications are discussed in relation to possible anatomic and physiologic differences for cleft palate subjects compared to normal.