Decrease in Prevalence of Cleft lip, Alveolus and Palate After Nationwide Introduction of the Second-Trimester Anomaly Scan in the Netherlands.

OBJECTIVE: Some studies have suggested that introducing a second-trimester anomaly scan (SAS) leads to increased rates of termination of pregnancy (TOP) in fetuses with orofacial clefts (OFCs). The aim of this study was to evaluate the impact of a nationwide introduction of SAS on the prevalence of live births with OFCs in the Netherlands. DESIGN: Retrospective cohort study. SETTING: Tertiary setting. POPULATION: Included in the study were all patients diagnosed with OFCs as recorded in the "Dutch Association for Cleft Palate Anomalies" database between 1997 and 2019. INTERVENTIONS: Patients were divided into three categories: cleft lip with or without alveolus (CL/A), cleft lip, alveolus and palate (CLAP) and cleft palate (CP) based on anatomical landmarks at the first consultation. MAIN OUTCOME MEASURES: Prevalence rates of OFCs before and after the nationwide introduction of the SAS on January 1, 2007 were compared. RESULTS: Overall, 1899 patients were diagnosed with CL/A, 2586 with CLAP and 2927 with CP. The prevalence of clefts before and after introduction of the SAS did not differ (P = 0.85). The prevalence of CL/A decreased (P = 0.04), and that of CLAP decreased (P = 0.01) and that of CP increased (P = 0.02). CONCLUSIONS: This study demonstrates a significant decrease in the prevalence of CL/A and CLAP after introduction of the SAS. However, due to an increase in CP, the prevalence of all patients born with OFCs has not changed in the Netherlands between 1997 and 2019.

Seasonal Influence on the Numbers of Gender-Related Orofacial Cleft Conceptions in the Netherlands.

BACKGROUND: In the multifactorial etiology of orofacial clefts (OFCs), environmental factors play an important role. To trace the influence of these factors, the timing of the cell biological mechanisms that occur during embryological development of the primary and secondary palates must be taken into account. That is, the fusion process of the facial and palatal processes, respectively, followed by their differentiation into bone and musculature, which take place during the first trimester of pregnancy. During this period, harmful seasonal influences such as viral infections and vitamin deficiencies could induce OFC in the embryo. AIMS: The aim of this study is to find out whether a seasonal conception period with an increased risk of OFC development exists, particularly gender related. METHODS: This was a retrospective cross-sectional study on children with OFC born in the Netherlands from 2006 to 2016. Total conception rates of live births in the Netherlands were used as a control group. χ2 tests were performed to analyze monthly and seasonal differences. Males and females, positive and negative family history and subphenotype groups based on fusion and/or differentiation (F- and/or D-) defects, and their timing in embryogenesis were analyzed separately. RESULTS: In total, 1653 children with OFC, 1041 males and 612 females, were analyzed. Only males with FD-defects showed a significant seasonal variation with an increase in conceptions during spring, most often in May. CONCLUSIONS: Males with FD-defects showed a significant seasonal variation with an increase in conceptions during spring. No other seasonal trends could be demonstrated.

Embryologically Based Classification Specifies Gender Differences in the Prevalence of Orofacial Cleft Subphenotypes.

BACKGROUND: A recently published validated classification system divides all orofacial cleft (OFC) subphenotypes into groups based on underlying developmental mechanisms, that is, fusion and differentiation, and their timing, that is, early and late periods, in embryogenesis of the primary and secondary palates. AIMS: The aim of our study was to define gender differences in prevalence for all subphenotypes in newborns with OFC in the Netherlands. METHODS: This was a retrospective cross-sectional study on children with OFC born from 2006 to 2016. Clefts were classified in early (E-), late (L-), and early/late (EL-) embryonic periods, in primary (P-), secondary (S-), and primary/secondary (PS-) palates, and further divided into fusion (F-), differentiation (D-), and fusion/differentiation (FD-) defects, respectively. RESULTS: A total of 2089 OFC children were analyzed (1311 males and 778 females). Orofacial cleft subphenotypes in females occurred significantly more frequent in the L-period compared to males (66% vs 55%, P = .000), whereas clefts in males occurred significantly more in the EL-periods (40% vs 27%, P = .000). Females had significantly more S-palatal clefts (42% vs 23%, P = .000), while males had significantly more PS-palatal clefts (44% vs 30%, P = .000). Furthermore, the clefts in females were significantly more frequent the result of an F-defect (60% vs 52%, P = .000). CONCLUSIONS: Orofacial cleft in females mainly occur in the L-period are mostly S-palatal clefts, and are usually the result of an F-defect. Orofacial cleft in males more commonly occur in the EL-periods, are therefore more often combined PS-palatal clefts, and are more frequent D- and FD-defects.

Subphenotyping and Classification of Cleft Lip and Alveolus in Adult Unoperated Patients: A New Embryological Approach.

OBJECTIVE: Previously, a new embryological classification was introduced subdividing oral clefts into fusion and/or differentiation defects. This subdivision was used to classify all subphenotypes of cleft lip with or without alveolus (CL±A). Subsequently, it was investigated whether further morphological grading of incomplete CLs is clinically relevant, and which alveolar part is deficient in fusion/differentiation defects. DESIGN: Observational cohort study. SETTING: Three hundred fifty adult unoperated Indonesian cleft patients presented themselves for operation. Cephalograms, dental casts, and intraoral and extraoral photographs-eligible for the present study-were used to determine morphological severity of CL±A. PATIENTS: Patients with unilateral or bilateral clefts of the primary palate only were included. MAIN OUTCOME MEASURES: Clefts were classified-according to developmental mechanisms and timing in embryogenesis-as fusion and/or differentiation defects. Grades of incomplete CLs were related to the severity of alveolar clefts (CAs) and hypoplasia, and permanent dentition was used to investigate which alveolar part is deficient in fusion/differentiation defects. RESULTS: One hundred eight adult patients were included. All subphenotypes-96 unilateral and 12 bilateral clefts-could be classified into differentiation (79%), fusion (17%), fusion-differentiation (2%), or fusion and differentiation (2%) defects. The various grades of incomplete CLs were related to associated CAs and hypoplasia, and all alveolar deformities were located in the premaxillae. CONCLUSIONS: This study showed that all CL±A including the Simonart bands can be classified, that further morphological grading of incomplete CLs is clinically relevant, and that the premaxilla forms the deficient part in alveolar deformities.

Classifying common oral clefts: a new approach after descriptive registration.

OBJECTIVE: Using the Dutch Oral Cleft Registration, which records the morphology and topography of common oral clefts, a new classification based on the (patho)embryology of the primary and secondary palates was tested. DESIGN: Prospective observational study. SETTING: The fifteen cleft palate teams in the Netherlands register patients to the national registry. PATIENTS: All unoperated patients with common oral clefts reported between 1997 and 2006 inclusive were included. MAIN OUTCOME MEASURES: The classification is based on the pathoembryological events that ultimately result in various subphenotypes of common oral clefts. PATIENTS within the three categories cleft lip/alveolus (CL/A), cleft lip/alveolus and palate (CL/AP), and cleft palate (CP) were divided into three subgroups: fusion defects, differentiation defects, and fusion and differentiation defects. A timetable was constructed to relate the type of clefting to the time of derailment during embryonic development. RESULTS: 3512 patients were included. PATIENTS with CL/A showed 22% fusion defects, 75% differentiation defects, and 3% fusion and differentiation defects. CL/AP patients and CP patients mostly showed fusion defects (70% and 89%, respectively). We were able to relate almost all (over 90%) cleft subphenotypes to specific weeks in embryonic development. CONCLUSIONS: This classification provides new cleft subgroups that may be used for clinical and fundamental research. The subphenotypes of these subgroups originate from different time frames during embryonic development and different cell biological mechanisms, thereby enabling more accurate data for, e.g., gene identification and/or environmental factors.

Periconceptional folic acid associated with an increased risk of oral clefts relative to non-folate related malformations in the Northern Netherlands: a population based case-control study.

Periconceptional folic acid has been associated with a reduced risk of neural tube defects, but findings on its effect in oral clefts are largely inconclusive. This case-control study assesses the effects of periconceptional folic acid on cleft risk, using complementary data from the Dutch Oral Cleft Registry and a population-based birth defects registry (Eurocat) of children and foetuses born in the Northern Netherlands between 1997 and 2009. Cases were live-born infants with non-syndromic clefts (n = 367) and controls were infants or foetuses with chromosomal/syndromal (n = 924) or non-folate related anomalies (n = 2,021). We analyzed type/timing/duration of supplement use related to traditional cleft categories as well as to their timing (early/late embryonic periods) and underlying embryological processes (fusion/differentiation defects). Consistent supplement use during the aetiologically relevant period (weeks 0-12 postconception) was associated with an increased risk of clefts (adjusted odds ratio 1.72, 95% confidence interval 1.19-2.49), especially of cleft lip/alveolus (3.16, 1.69-5.91). Further analysis systematically showed twofold to threefold increased risks for late differentiation defects-mainly clefts of the lip/alveolus-with no significant associations for early/late fusion defects. Effects were attributable to folic acid and not to other multivitamin components, and inclusion of partial use (not covering the complete aetiologically relevant period) generally weakened associations. In conclusion, this study presents several lines of evidence indicating that periconceptional folic acid in the Northern Netherlands is associated with an increased risk of clefts, in particular of cleft lip/alveolus. This association is strengthened by the specificity, consistency, systematic pattern, and duration of exposure-response relationship of our findings, underlining the need to evaluate public health strategies regarding folic acid and to further investigate potential adverse effects.

A systematic review of associated structural and chromosomal defects in oral clefts: when is prenatal genetic analysis indicated?

BACKGROUND: Oral clefts-comprising cleft lip (CL), cleft lip with cleft palate (CLP), and cleft palate (CP)-are being diagnosed prenatally more frequently. Consequently, the need for accurate information on the risk of associated anomalies and chromosomal defects to aid in prenatal counselling is rising. This systematic review was conducted to investigate the prenatal and postnatal prevalence of associated anomalies and chromosomal defects related to cleft category, thereby providing a basis for prenatal counselling and prenatal invasive diagnostics. METHODS: Online databases were searched for prenatal and postnatal studies on associated anomalies and chromosomal defects in clefts. Data from the literature were complemented with national validated data from the Dutch Oral Cleft Registry. RESULTS: Twenty studies were included: three providing prenatal data, 13 providing postnatal data, and four providing both. Data from prenatal and postnatal studies showed that the prevalence of associated anomalies was lowest in CL (0-20.0% and 7.6-41.4%, respectively). For CLP, higher frequencies were found both prenatally (39.1-66.0%) and postnatally (21.1-61.2%). Although CP was barely detectable by ultrasound, it was the category most frequently associated with accompanying defects in postnatal studies (22.2-78.3%). Chromosomal abnormalities were most frequently seen in association with additional anomalies. In the absence of associated anomalies, chromosomal defects were found prenatally in CLP (3.9%) and postnatally in CL (1.8%, 22q11.2 deletions only), CLP (1.0%) and CP (1.6%). CONCLUSIONS: Prenatal counselling regarding prognosis and risk of chromosomal defects should be tailored to cleft category, and more importantly to the presence/absence of associated anomalies. Irrespective of cleft category, clinicians should advise invasive genetic testing if associated anomalies are seen prenatally. In the absence of associated anomalies, prenatal conventional karyotyping is not recommended in CL, although array comparative genomic hybridisation should be considered. In presumed isolated CLP or CP, prenatal invasive testing, preferably by array based methods, is recommended.

Regional variation in prevalence of oral cleft live births in the Netherlands 1997-2007: time-trend analysis of data from three Dutch registries.

The Eurocat registry Northern Netherlands (NNL) has been used in regional context, as well as in national/international context, to describe the epidemiology of oral clefts (OC). However, the region NNL seems to have prevalence data different from Dutch national registries and certain other European areas. This may be due to differences in registration methods or geographical variation. To investigate whether the prevalence of OC live births varies regionally in the Netherlands, we established time trends for NNL and the rest of the Netherlands over 1997-2007 using data from two national registries (the OC Registry and The Netherlands Perinatal Registry) and a regional registry (Eurocat NNL). We found that the overall live-birth prevalence-comprising cleft lip/alveolus ± cleft palate and cleft palate only-was significantly higher in NNL (15.1-21.4 per 10,000) than in the rest of the Netherlands (13.2-16.1 per 10,000). None of the registries showed significant trends for NNL, whereas both national registries showed that the live-birth prevalence of cleft lip/alveolus ± cleft palate decreased significantly in the rest of the Netherlands. Despite some differences in prevalence between the registries, they showed similar regional variation in prevalence and trends. In conclusion, the prevalence of OC live births varies significantly in the Netherlands, not only between but also within registries. This underlines that extrapolation of regional cleft data should be done with caution. To further investigate OC etiology and evaluate preventive strategies, future studies should consider geographical differences-between and within countries-regarding the various cleft sub-phenotypes among live births, stillbirths, and pregnancy terminations.

Validation of the Dutch registry of common oral clefts: quality of recording specific oral cleft features.

OBJECTIVE: Since 1997, common oral clefts in the Netherlands have been recorded in the national oral cleft registry using a unique descriptive recording system. This study validates data on the topographic-anatomical structure, morphology, and side of individual anomalies of the primary palate and secondary palate that form the oral cleft. DESIGN: Validation study. SETTING: All 15 Dutch cleft palate teams reporting presurgery oral cleft patients to the national registry. PATIENTS: A random sample of 250 cases registered in the national database with oral clefts from 1997 through 2003; of these, 13 cases were excluded. MAIN OUTCOME MEASURES: By linking registry data with clinical data, we identified differential recording rates by comparing the prevalence, and we measured the degree of agreement by computing validity and reliability statistics. RESULTS: The topographic-anatomical structures (lip, alveolus, and hard and soft palates) of the anomalies had near-perfect interdatabase agreement with a sensitivity of 88% to 99%. However, when analyzing the individual anomalies in detail (morphology and side), validity decreased and depended on morphological severity. This association was most evident for anomalies of the secondary palate. For example, sensitivity was higher for "complete cleft hard palate" (92%) than for "submucous cleft hard/soft palate" (69%). CONCLUSIONS: Overall, the validity of Dutch registry data on oral clefts is good, supporting the feasibility of this unique recording system. However, when analyzing oral cleft data in detail, the quality appears to be related to anatomical location and morphological severity. This might have implications for etiologic research based on registry data and for guidelines on neonatal examination.

Ten years recording common oral clefts with a new descriptive system.

OBJECTIVE: After introducing a new descriptive recording system for congenital craniofacial abnormalities in The Netherlands, common oral clefts are highlighted. DESIGN: Prospective observational study. SETTING: Fifteen cleft palate teams, united in the Dutch Association for Cleft Palate and Craniofacial Anomalies, registered patients from 1997 to 2006. PATIENTS: All unoperated patients with a common oral cleft were included. MAIN OUTCOME MEASURES: Detailed information and birth prevalence rates of cleft lip/alveolus, cleft lip/alveolus and palate, and cleft palate were provided, relating referral age, gender, family history, additional congenital abnormalities, and syndrome diagnoses to these three categories. RESULTS: This study included 3512 patients, resulting in an overall prevalence of 16.6 per 10,000 live births. Patients showed a cleft lip/alveolus (28%), a cleft lip/alveolus and palate (39%), or a cleft palate (33%). The three categories exhibited very heterogeneous cleft types. Mean referral age was 5.8 months (median 3 weeks). Birth weight was the lowest in cleft palate patients (3238 g; p < .001 to .009). Cleft palate patients showed less positive family history concerning congenital anomalies (23%, p < .001 to .013), but more syndrome diagnoses were established in this category (24%, p < .001). Ten percent of all cleft patients showed additional abnormalities of the head and neck area, and 13% displayed congenital anomalies of other systems. CONCLUSIONS: This new recording method allows adequate description of common oral clefts. Many cleft types exist within these three categories and should be differentiated, because they originate from different time frames and/or cell biological mechanisms during embryogenesis.

Clinical Practice Guidelines on the Treatment of Patients with Cleft Lip, Alveolus, and Palate: An Executive Summary.

Significant treatment variation exists in the Netherlands between teams treating patients with cleft lip, alveolus, and/or palate, resulting in a confusing and undesirable situation for patients, parents, and practitioners. Therefore, to optimize cleft care, clinical practice guidelines (CPGs) were developed. The aim of this report is to describe CPG development, share the main recommendations, and indicate knowledge gaps regarding cleft care. Together with patients and parents, a multidisciplinary working group of representatives from all relevant disciplines assisted by two experienced epidemiologists identified the topics to be addressed in the CPGs. Searching the Medline, Embase, and Cochrane Library databases identified 5157 articles, 60 of which remained after applying inclusion and exclusion criteria. We rated the quality of the evidence from moderate to very low. The working group formulated 71 recommendations regarding genetic testing, feeding, lip and palate closure, hearing, hypernasality, bone grafting, orthodontics, psychosocial guidance, dentistry, osteotomy versus distraction, and rhinoplasty. The final CPGs were obtained after review by all stakeholders and allow cleft teams to base their treatment on current knowledge. With high-quality evidence lacking, the need for additional high-quality studies has become apparent.

Validation of the NVSCA registry for common oral clefts: study design and first results.

OBJECTIVE: Since 1997 the Dutch Association for Cleft Palate and Craniofacial Anomalies (NVSCA) has maintained a national registry of congenital craniofacial anomalies. This study validates data on three common oral cleft categories (cleft lip/alveolus = CL/A; cleft lip/alveolus and palate = CL/AP; and cleft palate = CP) and general items. DESIGN: Retrospective observational study. SETTING: All 15 Dutch cleft palate teams registered presurgery patients with common oral clefts (n = 2553) from 1997 to 2003. PATIENTS: A random sample of 250 cases was used; 13 cases were excluded. MAIN OUTCOME MEASURES: The corresponding medical data were reviewed; these medical data served to validate the NVSCA registry data. Prevalence comparisons, 2 x 2 tables and validity measures were performed. RESULTS: The cleft categories most accurately recorded were CL/A and CP. Both categories had an observed agreement of 98%, kappa of 0.94, and a sensitivity and specificity of 97%. Cleft lip/alveolus and palate had an observed agreement of 95%, kappa of 0.89, a sensitivity of 90%, and a specificity of 99%. Regarding the general items, observed agreement and kappa were highest for adoption/foster child (99%; 0.76) and lowest for remarks about pregnancy (63%; 0.20). Sensitivity ranged from 25% (consanguinity) to 97% (white mother) and specificity was high for all items (>93%) except for white father and mother (approximately 35%). CONCLUSIONS: The NVSCA registry is a valuable tool for quality improvement and research because validity on all three common oral cleft categories is very good. Validity on the general items is reasonable to satisfying and appears to be related to the type of information.

Insight into the Pathophysiologic Mechanisms behind Cognitive Dysfunction in Trigonocephaly.

BACKGROUND: The relationship between trigonocephaly and cognitive problems might be explained by: secondary mechanical factors related to growth restriction of the skull, and primary structural defects caused by a shared mechanism related to brain developmental disorder(s) and skull malformation. However, because the exact pathophysiology remains unknown, we examined the pathophysiologic mechanisms behind cognitive dysfunction in patients with trigonocephaly, with an aim of providing a model for cognitive dysfunction based on routinely available variables. METHODS: Included were 72 patients with trigonocephaly who were operated on. Postoperatively, intelligence was assessed prospectively. The two independent variables, secondary mechanical and primary brain developmental mechanisms, were evaluated retrospectively. Computed tomographic imaging was used to assess skull volume and severity of the frontal stenosis (secondary mechanical factors), width of the central part of the lateral ventricles, and other structural brain anomalies (primary brain developmental factors). Extracranial congenital anomalies were also taken into account. RESULTS: No association was found between secondary mechanical factors and postoperative IQ score. Width of the central part of the lateral ventricles, and an interaction effect between this width and additional extracranial anomalies, showed a significant negative association with postoperative IQ. CONCLUSIONS: Primary brain developmental disorders seem to play an important role in the development of cognitive problems in trigonocephaly. Assessment of width of the central part of the lateral ventricle scores and additional extracranial congenital anomalies for the early prediction of cognitive problems in patients with trigonocephaly could be clinically valuable and can be performed using routinely available tools.

Nutrition and genes in the development of orofacial clefting.

Clefts of the lip, alveolus, and/or palate, which are called orofacial clefts (OFC), occur in 0.5 to 3 per 1000 live and stillbirths. The pathogenesis of these congenital malformations remains largely unknown, but evidence is increasing that both nutritional and genetic factors are involved. Unlike genetic factors, nutritional causes can be corrected and may therefore contribute to the prevention of OFC. The goal of this review is to summarize the embryogenesis and genes involved in OFC, and to give an overview of the nutrients and related genes in humans. Improving our knowledge of the role of nutrition, genes, and their interactions in the pathogenesis of OFC may stimulate the development of nutritional interventions for OFC prevention in the future.

Decreasing prevalence of oral cleft live births in the Netherlands, 1997-2006.

OBJECTIVES: The number of new oral cleft patients has fallen in the Netherlands. This may be explained by two hypotheses: (1) greater prenatal detection of congenital anomalies has led to more pregnancy terminations and (2) increased folic acid use has reduced the oral cleft risk. Both hypotheses would mainly apply to the category cleft lip/alveolus ± cleft palate (CL±P), since, unlike cleft palate only (CP), CL±P can be detected prenatally by two-dimensional (2D) ultrasound and develops during the period recommended for folic acid use. The authors aimed to determine trends in prevalence over 1997-2006 and to evaluate the hypotheses by stratifying trends by cleft category. METHODS: This study was a time-trend analysis of infants born alive with oral clefts in the Netherlands during 1997-2006 and registered in the national oral cleft registry. The authors calculated prevalence rates and the estimated annual percentage change (EAPC) for all oral clefts and the two categories. RESULTS: In 1997-2006, 3308 infants out of 1 970 872 live births had oral clefts, an overall prevalence per 10 000 live births of 16.8 (CL±P: 11.3; CP: 5.5). Time-trend analysis showed that the prevalence of all oral clefts decreased (EAPC -1.8%; 95% CI: -3.0% to -0.6%), as did the CL±P prevalence (EAPC -2.3%; 95% CI: -3.8% to -0.9%). No significant trends were found for the CP prevalence. CONCLUSIONS: Because the live-birth prevalence of CL±P decreased, that of all oral clefts decreased. These findings are in line with both hypotheses and may therefore have implications for prenatal counselling and folic acid policy.

The frontosphenoidal suture: fetal development and phenotype of its synostosis.

BACKGROUND: Isolated synostosis of the frontosphenoidal suture is very rare and difficult to diagnose. Little has been reported on the clinical presentation and fetal development of this suture. OBJECTIVE: To understand the development of the frontosphenoidal suture and the outcome of its synostosis. MATERIALS AND METHODS: We studied the normal fetal development of the frontosphenoidal suture in dry human skulls and the clinical features of four patients with isolated synostosis of the frontosphenoidal suture. RESULTS: The frontosphenoidal suture develops relatively late during the second trimester of pregnancy, which explains the mild phenotype when there is synostosis. This rare craniosynostosis results in a deformity that causes recession of the lateral part of the frontal bone and supraorbital rim, with minimal facial asymmetry. Three-dimensional CT is the best examination to confirm the diagnosis. CONCLUSION: Isolated frontosphenoidal synostosis should be considered in patients with unilateral flattening of the forehead at birth that does not improve within the first few months of life.

Clinical and genetic analysis of patients with Saethre-Chotzen syndrome.

BACKGROUND: Saethre-Chotzen syndrome is a craniosynostosis syndrome further characterized by distinctive facial and limb abnormalities. It shows complete penetrance and variable expressivity and has been linked to the TWIST gene on chromosome 7p21; more than 80 different intragenic mutations and, recently, large deletions have been detected in Saethre-Chotzen patients. The aim of this study was to genetically and phenotypically characterize patients with a clinical diagnosis of Saethre-Chotzen syndrome. METHODS: Patients with a clinical diagnosis as well as those with a genetic diagnosis of Saethre-Chotzen syndrome (n = 34) were included in the study. RESULTS: The study showed that the important features of Saethre-Chotzen syndrome are brachycephaly (occurring in 74 percent of patients), a broad, depressed nasal bridge (65 percent), a high forehead (56 percent), ptosis (53 percent), and prominent auricular crura (56 percent). Furthermore, using different molecular techniques, pathogenic mutations in the TWIST gene were identified in 71 percent of patients. CONCLUSIONS: Patients with deletions of the TWIST gene did not differ from those with intragenic TWIST mutations in frequency or severity of craniofacial abnormalities. However, they did distinguish themselves by the presence of many additional anomalies and diseases and--most importantly--the high frequency of mental retardation, which was borderline significant. The authors conclude that when using stringent inclusion criteria for studies of Saethre-Chotzen syndrome, patients who have a pathogenic mutation of the TWIST gene should be excluded.

Crouzon syndrome: phenotypic signs and symptoms of the postnatally expressed subtype.

In a retrospective study, the characteristics of a group of patients (n = 9) with a postnatally expressed Crouzon syndrome were described. Although they do not always display the physical signs of craniosynostosis, such patients are highly at risk of developing symptoms secondary to multiple suture synostosis. By reviewing the hospital files, radiographs, and three-dimensional computed tomography scans of these patients, it was possible to describe the pattern of suture obliteration chronologically. Furthermore, certain phenotypic signs and symptoms such as skull shape and development of digital impressions, a bulge at the bregma, and intracranial hypertension were inventoried as well as patients' genotypes. Interestingly, ossification started at the lambdoid sutures in at least four patients and most likely in three additional ones. The coronal sutures were the last to ossify in at least three of the patients. Various skull shapes were encountered. Furthermore, all nine patients developed digital impressions, starting occipitally in eight of them. Seven patients developed a bulge at the bregma, and four of them exhibited intracranial hypertension. The genotype varied in our patients. To recognize patients with postnatal Crouzon syndrome as soon as possible, special attention must be paid to 1) occipital development of digital impressions and/or ossification of sutures, 2) development of a prominent bregma, 3) development of intracranial hypertension, and/or 4) progressive characteristic "crouzonoid" features. Such patients can be considered as representing a subtype of Crouzon syndrome. To prevent or treat intracranial hypertension and/or loss of vision, surgical intervention should be performed at the onset of progressive craniosynostosis between 1 and 2 years of age.

Parietal bone agenesis and associated multiple congenital anomalies.

Congenital defects of the calvaria in general and the parietal bones in particular are rare diseases. The latter are of three kinds: 1) cranioschisis, 2) craniodysostosis, and 3) foramina parietalia permagna (FPP). Here, we describe an exceptional anomaly, namely, complete absence of one parietal bone and dysplasia of the other. Agenesis has been reported twice before in the literature. In these cases, the calvarial defect was the only congenital anomaly. In contrast, the patient described in this article exhibited many other congenital deformities, namely, iris coloboma, facial dysmorphism, a large ventricular septal defect of the heart, and a horseshoe kidney. Some of these deformities are associated with neural crest development. Chromosomal analysis was normal in both blood and fibroblasts, and fluorescent in situ hybridization analysis failed to demonstrate a 22q11 deletion as seen in DiGeorge syndrome, a neural crest-related disease complex. Since 2000, the third group of congenital defects of the parietal bones, FPP, has been associated with mutations of the MSX-2 gene. In our case, a genetic analysis of this gene was performed, but no mutations or deletions of MSX-2 were detected.

Postnatal onset of craniosynostosis in a case of Saethre-Chotzen syndrome.

Saethre-Chotzen syndrome is a craniosynostosis syndrome characterized by facial and limb abnormalities. It is caused by mutations in the TWIST gene on chromosome 7p21. To date, more than 80 different mutations in TWIST have been reported in the literature.Recently, large deletions of chromosome 7p, encompassing the TWIST locus, have been detected in patients with clinical features of Saethre-Chotzen syndrome. Strikingly, all these patients were severely mentally retarded, which is otherwise a rare finding in Saethre-Chotzen syndrome. The authors report a patient with a large TWIST/7p deletion but with normal development. Furthermore, craniosynostosis was not present at birth or at the age of 4 months. However, skull radiographs taken at the age of 14 months showed stenosis of both coronal sutures, as well as of part of the sagittal suture. Reports on postnatal onset of craniosynostosis have been made in Crouzon syndrome but, to the authors' knowledge, never in Saethre-Chotzen syndrome.