Dominant frontonasal dysplasia with ectodermal defects results from increased activity of ALX4

Frontonasal dysplasia (FND) refers to a group of rare developmental disorders characterized by abnormal morphology of the craniofacial region. We studied a family manifesting with clinical features typical for FND2 including neurobehavioral abnormalities, hypotrichosis, hypodontia, and facial dysmorphism. Whole-exome sequencing analysis identified a novel heterozygous frameshift insertion in ALX4 (c.985_986insGTGC, p.Pro329Argfs*115), encoding aristaless homeobox 4. This and a previously reported dominant FND2-causing variant are predicted to result in the formation of a similar abnormally elongated protein tail domain. Using a reporter assay, we showed that the elongated ALX4 displays increased activity. ALX4 negatively regulates the Wnt/β-catenin pathway and accordingly, patient keratinocytes showed altered expression of genes associated with the WNT/β-catenin pathway, which in turn may underlie ectodermal manifestations in FND2. In conclusion, dominant FND2 with ectodermal dysplasia results from frameshift variants in ALX4 exerting a gain-of-function effect.

Oculoauriculofrontonasal syndrome: Refining the phenotype through a new case series and literature review

The oculoauriculofrontonasal syndrome (OAFNS) is a rare condition, with unknown etiology, characterized by the association of frontonasal dysplasia (FND) and oculoauriculovertebral spectrum (OAVS). Main clinical findings include widely spaced eyes, epibulbar dermoid, broad nose, mandibular hypoplasia, and preauricular tags. Here, we describe a case series of 32 Brazilian individuals with OAFNS and review the literature ascertaining individuals presenting phenotypes compatible with the diagnosis of OAFNS, aiming to refine the phenotype. This series emphasizes the phenotypic variability of the OAFNS and highlights the occurrence of rare craniofacial clefts as a part of the phenotype. The ectopic nasal bone, a hallmark of OAFNS, was frequent in our series, reinforcing the clinical diagnosis. The absence of recurrence, consanguinity, chromosomal, and genetic abnormalities reinforces the hypothesis of a nontraditional inheritance model. The phenotypic refinement provided by this series contributes to an investigation regarding the etiology of OAFNS.

Case report: Craniofrontonasal syndrome caused by a novel variant in the EFNB1 gene in a Colombian woman

Craniofrontonasal Syndrome is a very rare dominant X-linked genetic disorder characterized by symptoms such as hypertelorism, craniosynostosis, eye alterations, bifid nose tip, and longitudinal ridging and splitting of nails. Heterozygous females are usually the patients severely affected. To date, clinical or genetic data have not been published for these patients in Colombia. Here we report a female proband with coronal craniosynostosis, hypertelorism, strabismus, rotational nystagmus, high-arched palate, dental crowding, scoliosis, severe pectus excavatum, unilateral breast hypoplasia, and brachydactyly; diagnosed with Craniofrontonasal Syndrome with the novel heterozygous variant c.374A>C (p.Glu125Ala) in the EFNB1 gene. So far, she has been treated with physical therapy and surgical correction of the bifid nose and an umbilical hernia. To the best of our knowledge, this is the first report of a patient with this rare genetic disorder in Colombia, expanding its mutational spectrum and highlighting the importance of genetic evaluation of patients with craniosynostosis and facial dysmorphism.

Frontonasal Dysplasia: A Diagnostic Challenge with Fetal MRI in Twin Pregnancy

Callosal agenesis is a complex condition with disruption in the steps such as cellular proliferation, migration, axonal growth, guidance, or glial patterning at the midline. Agenesis of the corpus callosum (AgCC) is associated with diverse midline craniofacial malformations affecting the frontal-cranial and midface skeleton. Diagnosing midline abnormalities prenatally can be challenging, especially in twin pregnancies, due to poor resolution of skull base structures on fetal MRI, basal cephalocele could be mistaken for fluid in the nasopharynx, motion limitation, and fetal positioning. Our case highlights the importance of evaluation for other associated midline anomalies when there is callosal agenesis.

Toward clinical and molecular dissection of frontonasal dysplasia with facial skin polyps: From Pai syndrome to differential diagnosis through a series of 27 patients

Unique or multiple congenital facial skin polyps are features of several rare syndromes, from the most well-known Pai syndrome (PS), to the less recognized oculoauriculofrontonasal syndrome (OAFNS), encephalocraniocutaneous lipomatosis (ECCL), or Sakoda complex (SC). We set up a research project aiming to identify the molecular bases of PS. We reviewed 27 individuals presenting with a syndromic frontonasal polyp and initially referred for PS. Based on strict clinical classification criteria, we could confirm only nine (33%) typical and two (7%) atypical PS individuals. The remaining ones were either OAFNS (11/27-41%) or presenting with an overlapping syndrome (5/27-19%). Because of the phenotypic overlap between these entities, OAFNS, ECCL, and SC can be either considered as differential diagnosis of PS or part of the same spectrum. Exome and/or genome sequencing from blood DNA in 12 patients and from affected tissue in one patient failed to identify any replication in candidate genes. Taken together, our data suggest that conventional approaches routinely utilized for the identification of molecular etiologies responsible for Mendelian disorders are inconclusive. Future studies on affected tissues and multiomics studies will thus be required in order to address either the contribution of mosaic or noncoding variation in these diseases.

Rhinoplasty in a 3 Week Old: Surgical Challenges in the Setting of Severe Congenital Frontonasal Dysplasia

OBJECTIVES

Congenital frontonasal dysplasia (CFND) is a rare heterogeneous collection of facial deformities. Due to the range of complexity, surgical management is not standardized.

METHODS

We present a severe case of CFND and approach to managing multiple defects with a focus on rhinoplasty.

RESULTS

This infant was born full term with a large mass instead of a nose, a bilateral cleft lip and palate, and hypertelorbitism. Our primary concerns initially were to address communication with the intracranial cavity, preserve a nasal lining, and improve nasal appearance and airway function in the short term without interfering with subsequent rhinoplasty and adult nasal appearance.

CONCLUSIONS

This complex case of CFND is more severe than anything we encountered in our literature review and demonstrates the necessity for multidisciplinary approach to multiple craniofacial defects. Future plans for this patient include rhinoplasty with auricular graft, scar revision, and addressing tip support.

Nasal Reconstruction of a Frontonasal Dysplasia via Septal L-Strut Reconstruction Using Costal Cartilage

OBJECTIVE

Frontonasal dysplasia (FND) is a rare congenital condition. Its major features include hypertelorism, a large and bifid nasal tip, and a broad nasal root. We present our technique of septal L-strut reconstruction using costal cartilage.

DESIGN

Retrospective review from June 2008 and August 2017.

METHODS

Under general anesthesia, 6 patients with FND underwent septal reconstruction using costal cartilage via open rhinoplasty. We reconstructed the nasal and septal cartilaginous framework by placing columellar struts and cantilever-type grafts.

RESULTS

The patients ranged in age from 6 to 13 years old. All were female. The follow-up period ranged from 8 months to 2 years; we encountered no postoperative complications (infection, nasal obstruction, or recurrence). All patients were satisfied with their nasal appearance.

CONCLUSIONS

Although the results were not entirely satisfactory from an esthetic point of view, we found that FND can be treated via septal reconstruction with costal cartilage and that the clinical outcomes are reliable and satisfactory. Our approach is a useful option for FND patients.

ALX-Related Frontonasal Dysplasias: Clinical Characteristics and Surgical Management

AIM

The term frontonasal dysplasia (FND) represents a spectrum of anomalies and its genetics have not been well defined. Recently, the critical role of the aristaless-like homeobox (ALX) gene family on the craniofacial development has been discovered. In the present study, we aimed to propose a systematic surgical treatment plan for the ALX-related FNDs according to the genotypic classification as well as demonstrating their clinical characteristics to help surgeons diagnose the underlying pathology accurately.

DESIGN

Single-institution retrospective.

SETTING

Tertiary health care.

PATIENTS AND METHODS

Eighty-nine FND cases were evaluated. Eight of them had ALX1-related FND3, 3 had ALX3-related FND1, and 2 had ALX4-related FND2. Phenotype characteristics of ALX-related FNDs were evaluated, and relevant surgical interventions were assessed.

RESULTS

The ALX1-related FND3 phenotype is striking due to the involvement of the eyes in addition to the presence of hypertelorism, facial clefts, and nasal deformities. A widened philtrum and prominent philtral columns are remarkable features of the ALX3-related FND1, whereas the ALX4-related FND2 has more severe deformities: severe hypertelorism, brachycephaly, large parietal bone defects, broad nasal dorsum, and alopecia. Facial bipartition, box osteotomies, eyelid coloboma repair, cleft lip and palate repair, nasal reconstruction, and fronto-orbital advancement can be performed in ALX-related FNDs based on the characteristics of each subtype.

CONCLUSIONS

This genetic classification system will help surgeon diagnose patients with FND with unique features and draw a roadmap for their treatment with a better surgical perspective.

Prenatal diagnosis of isolated frontonasal dysplasia: A case report

We report a case of mild frontonasal dysplasia, a complex and rare malformation affecting the central portion of the face, especially the eyes, nose, and forehead, which was diagnosed at 20 weeks of gestation. The diagnosis was made by two- and four-dimensional ultrasound and confirmed at autopsy after pregnancy termination. A review of the literature is presented.

Surgical Management of a Mild Case of Frontonasal Dysplasia: A Case Report and Review of Literature

Frontonasal dysplasia (FND) is a rare congenital craniofacial cleft syndrome associated with a spectrum of midline facial bone and soft-tissue malformations. When present, the physical features of FND are often obvious and classified at birth. The resultant facial deformities have the potential to negatively influence psychosocial health and quality of life. Reconstructive surgical intervention in early childhood can serve to restore facial contour and alleviate psychological stress. In this report, a case of a 14-year-old female with previously undiagnosed mild form of FND presented for reconstructive surgery evaluation and underwent several procedures including sliding advanced genioplasty, submucosal resection of the nasal turbinates, open rhinoplasty, and bilateral transnasal medial canthopexies. The patient had subsequent nasal tip recontouring for persistent supratip fullness. The patient achieved an acceptable esthetic outcome and was satisfied with her physical appearance. This case emphasizes the subtle presentation and reconstructive surgical options of a mild case of FND that was diagnosed at a later age, unlike the more severe phenotypes of the syndrome and other common craniofacial anomalies that are usually diagnosed and treated in early childhood. Multidisciplinary craniofacial care teams should be able to correctly diagnose and implement the appropriate surgical interventions in patients with milder forms of FND.

ALX1-related frontonasal dysplasia results from defective neural crest cell development and migration

A pedigree of subjects presented with frontonasal dysplasia (FND). Genome sequencing and analysis identified a p.L165F missense variant in the homeodomain of the transcription factor ALX1 which was imputed to be pathogenic. Induced pluripotent stem cells (iPSC) were derived from the subjects and differentiated to neural crest cells (NCC). NCC derived from ALX1L165F/L165F iPSC were more sensitive to apoptosis, showed an elevated expression of several neural crest progenitor state markers, and exhibited impaired migration compared to wild-type controls. NCC migration was evaluated in vivo using lineage tracing in a zebrafish model, which revealed defective migration of the anterior NCC stream that contributes to the median portion of the anterior neurocranium, phenocopying the clinical presentation. Analysis of human NCC culture media revealed a change in the level of bone morphogenic proteins (BMP), with a low level of BMP2 and a high level of BMP9. Soluble BMP2 and BMP9 antagonist treatments were able to rescue the defective migration phenotype. Taken together, these results demonstrate a mechanistic requirement of ALX1 in NCC development and migration.

Maternal SLE and brachytelephalangic chondrodysplasia punctata in a patient with unrelated de novo RAF1 and SIX2 variants

Our improved tools to identify the aetiologies in patients with multiple abnormalities resulted in the finding that some patients have more than a single genetic condition and that some of the diagnoses made in the past are acquired rather than inherited. However, limited knowledge has been accumulated regarding the phenotypic outcome of the interaction between different genetic conditions identified in the same patients. We report a newborn girl with brachytelephalangic chondrodysplasia punctata (BCDP) as well as frontonasal dysplasia, ptosis, bilateral hearing loss, vertebral anomalies, and pulmonary hypoplasia who was found, by whole exome sequencing, to have a de novo pathogenic variant in RAF1 (c.770C>T, [p.Ser257Leu]) and a likely pathogenic variant in SIX2 (c.760G>A [p.A254T]), as well as maternal systemic lupus erythematosus (SLE). This case shows that BCDP is most probably not a diagnostic entity and can be associated with various conditions associated with CDP including maternal SLE.

A Novel Missense Variant in the ALX4 Gene Underlies Mild to Severe Frontonasal Dysplasia in a Consanguineous Family

Background: Frontonasal dysplasia (FND) is a rare developmental disorder characterized by mild to severe changes in skull and brain structures. It is a phenotypically variable and heterogeneous disorder. This study was designed to provide a clinical and genetic analysis of FND in a consanguineous family of Pakistani origin. Methodology and Results: Affected individuals in the family showed characteristic features of frontonasal dysplasia type-2 (FND2), such as nasal bone hypoplasia, hypertelorism, and alopecia. Skull and brain imaging of affected members revealed ossification defects and various types of brain structural anomalies that created a split-brain. Sanger sequencing of the ALX4 gene revealed a homozygous missense variant [NM_021926.4: c.652C>T; p.(Arg218Trp)] in three affected members who demonstrated severe craniofacial anomalies. Heterozygous carriers in the family showed mild FND2 phenotypes. Conclusion: Clinical and genetic analysis of a family, exhibiting FND2 phenotypes, revealed several previously unreported clinical features and a novel missense variant in the ALX4 gene. These results will facilitate diagnosis and genetic counseling of the FND patients in the Pakistani population.

Identification of a novel homozygous ALX4 mutation in two unrelated patients with frontonasal dysplasia type-2

We report two unrelated boys with frontonasal dysplasias type-2 (FND-2) who shared an identical novel homozygous ALX4 mutation c.291delG (p.Q98Sfs*83). Both patients presented with a large skull defect but one had bilateral parietal meningocele-like cysts that lie along with the bony defect and increased in size with age. Scalp alopecia, hypertelorism, and clefted alae nasi were also detected in both of them. Furthermore, impalpable gonads were noted, being unilateral in one and bilateral in the other. Neuroimaging showed small dysplastic occipital lobes with dysgyria and midline subarachnoid cyst. Additional dysplastic corpus callosum and small cerebellar vermis were observed in one patient. Parietal foramina were noted in the parents of one patient. Our findings highlight the dosage effect of ALX4 and underscore the challenges of prenatal genetic counseling. Further, the indirect role of ALX4 in the development of the occipital lobe and posterior fossa is discussed.

Crucial and Overlapping Roles of Six1 and Six2 in Craniofacial Development

SIX1 and SIX2 encode closely related transcription factors of which disruptions have been associated with distinct craniofacial syndromes, with mutations in SIX1 associated with branchiootic syndrome 3 (BOS3) and heterozygous deletions of SIX2 associated with frontonasal dysplasia defects. Whereas mice deficient in Six1 recapitulated most of the developmental defects associated with BOS3, mice lacking Six2 function had no obvious frontonasal defects. We show that Six1 and Six2 exhibit partly overlapping patterns of expression in the developing mouse embryonic frontonasal, maxillary, and mandibular processes. We found that Six1 ^-/- Six2 ^-/- double-mutant mice were born with severe craniofacial deformity not seen in the Six1 ^-/- or Six2 ^-/- single mutants, including skull bone agenesis, midline facial cleft, and syngnathia. Moreover, whereas Six1 ^-/- mice exhibited partial transformation of maxillary zygomatic bone into a mandibular condyle-like structure, Six1 ^-/-Six2 ^+/- mice exhibit significantly increased penetrance of the maxillary malformation. In addition to ectopic Dlx5 expression at the maxillary-mandibular junction as recently reported in E10.5 Six1 ^-/- embryos, the E10.5 Six1 ^-/- Six2 ^+/- embryos showed ectopic expression of Bmp4, Msx1, and Msx2 messenger RNAs in the maxillary-mandibular junction. Genetically inactivating 1 allele of either Ednra or Bmp4 significantly reduced the penetrance of maxillary malformation in both Six1 ^-/- and Six1 ^-/- Six2 ^+/- embryos, indicating that Six1 and Six2 regulate both endothelin and bone morphogenetic protein-4 signaling pathways to pattern the facial structures. Furthermore, we show that neural crest-specific inactivation of Six1 in Six2 ^-/- embryos resulted in midline facial cleft and frontal bone agenesis. We show that Six1 ^-/- Six2 ^-/- embryos exhibit significantly reduced expression of key frontonasal development genes Alx1 and Alx3 as well as increased apoptosis in the developing frontonasal mesenchyme. Together, these results indicate that Six1 and Six2 function partly redundantly to control multiple craniofacial developmental processes and play a crucial neural crest cell-autonomous role in frontonasal morphogenesis.

The oculoauriculofrontonasal syndrome: Further clinical characterization and additional evidence suggesting a nontraditional mode of inheritance

The oculoauriculofrontonasal syndrome (OAFNS) is a rare disorder characterized by the association of frontonasal dysplasia (widely spaced eyes, facial cleft, and nose abnormalities) and oculo-auriculo-vertebral spectrum (OAVS)-associated features, such as preauricular ear tags, ear dysplasia, mandibular asymmetry, epibulbar dermoids, eyelid coloboma, and costovertebral anomalies. The etiology is unknown so far. This work aimed to identify molecular bases for the OAFNS. Among a cohort of 130 patients with frontonasal dysplasia, accurate phenotyping identified 18 individuals with OAFNS. We describe their clinical spectrum, including the report of new features (micro/anophtalmia, cataract, thyroid agenesis, polymicrogyria, olfactory bulb hypoplasia, and mandibular cleft), and emphasize the high frequency of nasal polyps in OAFNS (56%). We report the negative results of ALX1, ALX3, and ALX4 genes sequencing and next-generation sequencing strategy performed on blood-derived DNA from respectively, four and four individuals. Exome sequencing was performed in four individuals, genome sequencing in one patient with negative exome sequencing result. Based on the data from this series and the literature, diverse hypotheses can be raised regarding the etiology of OAFNS: mosaic mutation, epigenetic anomaly, oligogenism, or nongenetic cause. In conclusion, this series represents further clinical delineation work of the rare OAFNS, and paves the way toward the identification of the causing mechanism.

Clinical delineation of a subtype of frontonasal dysplasia with creased nasal ridge and upper limb anomalies: Report of six unrelated patients

Frontonasal dysplasias are rare congenital malformations of frontonasal process-derived structures, characterized by median cleft, nasal anomalies, widely spaced eyes, and cranium bifidum occultum. Several entities of syndromic frontonasal dysplasia have been described, among which, to date, only a few have identified molecular bases. We clinically ascertained a cohort of 124 individuals referred for frontonasal dysplasia. We identified six individuals with a similar phenotype, including one discordant monozygous twin. Facial features were remarkable by nasal deformity with creased ridge and depressed or absent tip, widely spaced eyes, almond-shaped palpebral fissures, and downturned corners of the mouth. All had apparently normal psychomotor development. In addition, upper limb anomalies, frontonasal encephalocele, corpus callosum agenesis, choanal atresia, and congenital heart defect were observed. We identified five reports in the literature of patients presenting with the same phenotype. Exome sequencing was performed on DNA extracted from blood of two individuals, no candidate gene was identified. In conclusion, we report six novel simplex individuals presenting with a specific frontonasal dysplasia entity associating recognizable facial features, limb and visceral malformations, and apparently normal development. The identification of discordant monozygotic twins supports the hypothesis of a mosaic disorder. Although previous patients have been reported, this is the first series, allowing delineation of a clinical subtype of frontonasal dysplasia, paving the way toward the identification of its molecular etiology.

A new frontonasal dysplasia syndrome associated with deletion of the SIX2 gene

The frontonasal dysplasias are a group of craniofacial phenotypes characterized by hypertelorism, nasal clefting, frontal bossing, and abnormal hairline. These conditions are caused by recessive mutations in members of the aristaless gene family, resulting in abnormal cranial neural crest migration and differentiation. We report a family with a dominantly inherited craniofacial phenotype comprised of frontal bossing with high hairline, ptosis, hypertelorism, broad nasal tip, large anterior fontanelle, cranial base anomalies, and sagittal synostosis. Chromosomal microarray identified a heterozygous 108.3 kilobase deletion of chromosome 2p21 segregating with phenotype and limited to the sine oculis homeobox gene SIX2 and surrounding noncoding DNA. Similar to the human SIX2 deletion phenotype, one mouse model of frontonasal dysplasia, brachyrrhine, exhibits dominant inheritance and impaired cranial base chondrogenesis associated with reduced Six2 expression. We report the first human autosomal dominant frontonasal dysplasia syndrome associated with SIX2 deletion and with phenotypic similarities to murine models of Six2 Loss-of-function.

Oropharyngeal teratoma, oral duplication, cervical diplomyelia and anencephaly in a 22-week fetus: A review of the craniofacial teratoma syndrome

BACKGROUND

Oropharyngeal teratoma may occur by itself or together with other craniofacial malformations, most commonly cleft palate. Oropharyngeal teratoma may be also seen in association with frontonasal dysplasia and/or various degrees of craniofacial duplication. The nosology of these sporadic disorders is poorly defined.

CASE AND REVIEW

We report on a 22-week fetus with a protruding nasopharyngeal teratoma, partial oral duplication, anencephaly, multiple costo-vertebral segmentation defects, and cervical diplomyelia. A review of the literature identified 48 patients published from 1931 to 2013 with co-existing clefting and duplication anomalies of the cephalic pole. Thoracic and abdominal midline anomalies were reported 13 times.

CONCLUSION

The term "craniofacial teratoma syndrome" is introduced to define this phenotype as a recognizable developmental field defect of the cephalic pole. Developmental pathogenesis is discussed with a focus on pleiotropy and stereotaxis. The observation of midline findings suggestive of holoprosencephaly in a few previously reported cases suggests a role for the sonic hedgehog signaling pathway in this malformation pattern.

A Diagnostic Conundrum: Ectopic Nasal Ossification, Submucosal Alveolar Cleft, Absent Posterior Atlantal Arch, and Corpus Callosum Lipoma

A 19-year-old woman was referred for nasal breathing and aesthetic concerns regarding her nose. A computed tomography scan revealed a massive osseous shield anterior to the piriform aperture. Furthermore, there was a submucosal median alveolar cleft, and the posterior arch of C1 was missing. The magnetic resonance imaging brain scan revealed a curvilinear lipoma of corpus callosum. The ectopic nasal bone was removed by open rhinoplast,y and nasal function and aesthetics were restored. The described features defy conventional clinical diagnosis and severity classifications and present a diagnostic conundrum somewhere between a mild form of frontonasal dysplasia, oculoauriculofrontonasal syndrome, and Pai syndrome.

Prenatal diagnosis of frontonasal dysplasia associated with bilateral periventricular nodular heterotopia

Frontonasal dysplasia is an etiologically heterogeneous development alteration including a set of anomalies affecting the eyes, forehead, and nose as a result of a malformation of the frontonasal elevation. It could occur either in isolation or as part of a syndrome such as frontonasal dysplasia associated with periventricular heterotopia. Our goal is to document the first clinical case of prenatal diagnosis for frontonasal dysplasia associated with periventricular heterotopia by fetal magnetic resonance imaging (MRI) at weeks 19.5 and 29 and postnatal MRI. In conclusion, the presence of frontonasal dysplasia in a prenatal ultrasonography should always be followed by a fetal MRI with routine screening for periventricular nodular heterotopias so as to establish a more adequate prognosis for the family.

Frontonasal dysplasia (Median cleft face syndrome)

This is a report of a rare case of frontonasal dysplasia (FND) in a full-term girl with birth weight of 2.750 kg. The baby had the classical features of FND. There were no other associated anomalies. There was no history of consanguinity and no family history of similar conditions. So inheritance of this case could be considered sporadic. Maxillofacial surgery should be considered for all patients for whom improvement is possible. However, in developing countries where there are considerable limitations in provision of social services, with economic and educational constraints, correction of such major defects remains a challenging task.

Craniofacial ciliopathies: A new classification for craniofacial disorders

Craniofacial anomalies are some of the most variable and common defects affecting the population. Herein, we examine a group of craniofacial disorders that are the result of defects in primary cilia; ubiquitous, microtubule-based organelles that transduce molecular signals and facilitate the interactions between the cell and its environment. Based on the frequent appearance of craniofacial phenotypes in diseases born from defective primary cilia (ciliopathies) we propose a new class of craniofacial disorders referred to as craniofacial ciliopathies. We explore the most frequent phenotypes associated with ciliopathic conditions and the ciliary gene mutations responsible for craniofacial defects. Finally, we propose that some non-classified disorders may now be classified as craniofacial ciliopathies.

The Syndrome of Frontonasal Dysplasia, Callosal Agenesis, Basal Encephalocele, and Eye Anomalies - Phenotypic and Aetiological Considerations

We report ten sporadic cases of Brazilian patients with facial midline defects, callosal agenesis, basal encephalocele, and ocular anomalies. This very rare cluster of anomalies has been well reported before. However, only until recently it is recognized as a syndrome belonging to frontonasal dysplasia spectrum. The ten cases confirm a distinct clinical entity and help to define the phenotype more precisely than previously. Up to now etiology remains unknown, although we conjecture that it is due to a mutation in TGIF gene.