Augmentation of bone morphogenetic protein signaling in cranial neural crest cells in mice deforms skull base due to premature fusion of intersphenoidal synchondrosis

Craniofacial anomalies (CFAs) are a diverse group of disorders affecting the shapes of the face and the head. Malformation of the cranial base in humans leads CFAs, such as midfacial hypoplasia and craniosynostosis. These patients have significant burdens associated with breathing, speaking, and chewing. Invasive surgical intervention is the current primary option to correct these structural deficiencies. Understanding molecular cellular mechanism for craniofacial development would provide novel therapeutic options for CFAs. In this study, we found that enhanced bone morphogenetic protein (BMP) signaling in cranial neural crest cells (NCCs) (P0-Cre;caBmpr1a mice) causes premature fusion of intersphenoid synchondrosis (ISS) resulting in leading to short snouts and hypertelorism. Histological analyses revealed reduction of proliferation and higher cell death in ISS at postnatal day 3. We demonstrated to prevent the premature fusion of ISS in P0-Cre;caBmpr1a mice by injecting a p53 inhibitor Pifithrin-α to the pregnant mother from E15.5 to E18.5, resulting in rescue from short snouts and hypertelorism. We further demonstrated to prevent premature fusion of cranial sutures in P0-Cre;caBmpr1a mice by injecting Pifithrin-α through E8.5 to E18.5. These results suggested that enhanced BMP-p53-induced cell death in cranial NCCs causes premature fusion of ISS and sutures in time-dependent manner.

SPECC1L Mutations Are Not Common in Sporadic Cases of Opitz G/BBB Syndrome

Opitz G/BBB syndrome (OS) is a rare genetic developmental condition characterized by congenital defects along the midline of the body. The main clinical signs are represented by hypertelorism, laryngo–tracheo–esophageal defects and hypospadias. The X-linked form of the disease is associated with mutations in the MID1 gene located in Xp22 whereas mutations in the SPECC1L gene in 22q11 have been linked to few cases of the autosomal dominant form of this disorder, as well as to other genetic syndromes. In this study, we have undertaken a mutation screening of the SPECC1L gene in samples of sporadic OS cases in which mutations in the MID1 gene were excluded. The heterozygous missense variants identified are already reported in variant databases raising the issue of their pathogenetic meaning. Recently, it was reported that some clinical manifestations peculiar to OS signs are not observed in patients carrying mutations in the SPECC1L gene, leading to the proposal of the designation of ‘SPECC1L syndrome’ to refer to this disorder. Our study confirms that patients with diagnosis of OS, mainly characterized by the presence of hypospadias and laryngo–tracheo–esophageal defects, do not carry pathogenic SPECC1L mutations. In addition, SPECC1L syndrome-associated mutations are clustered in two specific domains of the protein, whereas the missense variants detected in our work lies elsewhere and the impact of these variants in the function of this protein is difficult to ascertain with the current knowledge and will require further investigations. Nonetheless, our study provides further insight into the SPECC1L syndrome classification.

Hydrothorax in fetal cases of Opitz G/BBB diagnosis: Extending the phenotype?

We report two fetal cases carrying a de novo MID1 mutation and presenting with severe hydrothorax, suggesting the expansion of the phenotype of Opitz GBBB syndrome.

Non-redundant roles in sister chromatid cohesion of the DNA helicase DDX11 and the SMC3 acetyl transferases ESCO1 and ESCO2

In a process linked to DNA replication, duplicated chromosomes are entrapped in large, circular cohesin complexes and functional sister chromatid cohesion (SCC) is established by acetylation of the SMC3 cohesin subunit. Roberts Syndrome (RBS) and Warsaw Breakage Syndrome (WABS) are rare human developmental syndromes that are characterized by defective SCC. RBS is caused by mutations in the SMC3 acetyltransferase ESCO2, whereas mutations in the DNA helicase DDX11 lead to WABS. We found that WABS-derived cells predominantly rely on ESCO2, not ESCO1, for residual SCC, growth and survival. Reciprocally, RBS-derived cells depend on DDX11 to maintain low levels of SCC. Synthetic lethality between DDX11 and ESCO2 correlated with a prolonged delay in mitosis, and was rescued by knockdown of the cohesin remover WAPL. Rescue experiments using human or mouse cDNAs revealed that DDX11, ESCO1 and ESCO2 act on different but related aspects of SCC establishment. Furthermore, a DNA binding DDX11 mutant failed to correct SCC in WABS cells and DDX11 deficiency reduced replication fork speed. We propose that DDX11, ESCO1 and ESCO2 control different fractions of cohesin that are spatially and mechanistically separated.

The E3 ubiquitin ligase MID1/TRIM18 promotes atypical ubiquitination of the BRCA2-associated factor 35, BRAF35

MID1/TRIM18 is a member of the TRIM family of ubiquitin E3 ligases characterized by the presence of a conserved RING-containing N-terminal tripartite motif. Mutations in the MID1 gene have been associated with the X-linked form of Opitz Syndrome, a developmental disorder characterized by midline defects and intellectual disability. The effect of MID1 E3 ligase activity within the cell and the role in the pathogenesis of the disease is still not completely unraveled. Here, we report BRAF35, a non-canonical HMG nuclear factor, as a novel MID1 substrate. MID1 is implicated in BRAF35 ubiquitination promoting atypical poly-ubiquitination via K6-, K27- and K29-linkages. We observed a partial co-localization of the two proteins within cytoplasmic bodies. We found that MID1 depletion alters BRAF35 localization in these structures and increases BRAF35 stability affecting its cytoplasmic abundance. Our data reveal a novel role for MID1 and for atypical ubiquitination in balancing BRAF35 presence, and likely its activity, within nuclear and cytoplasmic compartments.

Structural and functional observations of the P151L MID1 mutation reveal alpha4 plays a significant role in X-linked Opitz Syndrome

Mutations of human MID1 are associated with X-linked Opitz G Syndrome (XLOS), which is characterized by midline birth defects. XLOS-observed mutations within the MID1 B-box1 domain are associated with cleft lip/palate, wide-spaced eyes and hyperspadias. Three of the four XLOS-observed mutations in the B-box1 domain results in unfolding but the structural and functional effects of the P151L mutation is not characterized. Here, we demonstrate that the P151L mutation does not disrupt the overall tertiary structure of the B-box1 domain and the adjacent domains. In fact, MID1 E3 ligase activity is slightly enhanced. However, the P151L mutation disrupted the ability of MID1 to catalyze the poly-ubiquitination of alpha4, a novel regulator of PP2A. This observation is consistent with results observed with the other three structure-destabilizing B-box1 mutations in targeting alpha4 but not PP2A. Alpha4 is shown to bind and sequester the catalytic subunit of PP2A and protect it from MID1-mediated ubiquitination and as a result, an increase in alpha4 can contribute to an increase in PP2A, playing a greater role in midline development during embryogenesis.

Recurrent Mutations in the Basic Domain of TWIST2 Cause Ablepharon Macrostomia and Barber-Say Syndromes

Ablepharon macrostomia syndrome (AMS) and Barber-Say syndrome (BSS) are rare congenital ectodermal dysplasias characterized by similar clinical features. To establish the genetic basis of AMS and BSS, we performed extensive clinical phenotyping, whole exome and candidate gene sequencing, and functional validations. We identified a recurrent de novo mutation in TWIST2 in seven independent AMS-affected families, as well as another recurrent de novo mutation affecting the same amino acid in ten independent BSS-affected families. Moreover, a genotype-phenotype correlation was observed, because the two syndromes differed based solely upon the nature of the substituting amino acid: a lysine at TWIST2 residue 75 resulted in AMS, whereas a glutamine or alanine yielded BSS. TWIST2 encodes a basic helix-loop-helix transcription factor that regulates the development of mesenchymal tissues. All identified mutations fell in the basic domain of TWIST2 and altered the DNA-binding pattern of Flag-TWIST2 in HeLa cells. Comparison of wild-type and mutant TWIST2 expressed in zebrafish identified abnormal developmental phenotypes and widespread transcriptome changes. Our results suggest that autosomal-dominant TWIST2 mutations cause AMS or BSS by inducing protean effects on the transcription factor's DNA binding.

Intrapartum diagnostic of Roberts syndrome - case presentation

Roberts syndrome is a rare disease, with multiple limb and skeletal abnormalities (called "pseudothalidomide disease"). There are only around 150 cases described in literature. We present a case of Roberts syndrome, diagnosed in moment of delivery, after a pregnancy without prenatal follow-up. The stillborn baby was naturally delivered by a 17-year-old primiparous woman at 38 weeks of amenorrhea. The pregnancy was not followed due to socioeconomic and family situation, and no prenatal ultrasound was performed. The male baby has 2650 g and presented several morphological abnormalities and tight double umbilical abdominal loop. The macroscopic evaluation showed: dolichocephaly, hypoplastic inferior maxilla with micrognathia, antimongoloid palpebral slant, pterygium colli, abnormal and lower implanted ears, superior limbs phocomelia, syndactyly at lower left limb and tetradactyly in all limbs, bilateral cryptorchidism, pancreatic aplasia. Roberts syndrome is a rare genetic disease with recessive autosomal transmission generated by mutations in ESCO2 gene, located on chromosome 8. The disease should be easy to diagnose by antenatal ultrasound examination, but in our case, the lack of prenatal follow-up determined the diagnostic at term. We believe consider this case is an argument towards introducing ultrasound-screening compulsory to all pregnancies. To identify a possible genetic mutation, further investigations of the parents are in progress, but classically the disease has a recessive autosomal transmission.

Horizontal eye position in thyroid eye disease: a retrospective comparison with normal individuals and changes after orbital decompression surgery

Objective

To compare horizontal eye positions between proptotic thyroid eye disease patients and normal individuals, and to examine positional changes after orbital decompression surgery in thyroid eye disease patients.

Methods

The present case-controlled and retrospective comparative study included 78 proptotic thyroid eye disease patients who underwent bilateral orbital decompression surgery [lateral orbital wall decompression (Group L), 47 patients; medial orbital wall decompression (Group M), 9 patients; and balanced orbital decompression (Group B), 22 patients] and 143 age-matched healthy volunteers as controls. The interpupillary distance was measured to determine horizontal eye positions before and 3 months after surgery in thyroid eye disease patients and was also examined in control eyes. Horizontal eye shifts were calculated by subtracting postoperative from preoperative interpupillary distances.

Results

Preoperative interpupillary distances in thyroid eye disease patients were significantly larger than in controls. The interpupillary distances were significantly decreased postoperatively in Groups M and B, but were significantly increased in Group L. The order of the magnitude of the horizontal shifts was Groups M>B>L.

Conclusions

Proptotic thyroid eye disease patients preoperatively showed laterally displaced eyes in comparison with controls. However, the eyes shifted medially after the medial orbital wall decompression and the balanced orbital decompression, although the former showed more shift. Medial orbital wall or balanced orbital decompression can be used to correct both lateral and anterior displacement of the eyes.

MID1 catalyzes the ubiquitination of protein phosphatase 2A and mutations within its Bbox1 domain disrupt polyubiquitination of alpha4 but not of PP2Ac

MID1 is a microtubule-associated protein that belongs to the TRIM family. MID1 functions as an ubiquitin E3 ligase, and recently was shown to catalyze the polyubiquitination of, alpha4, a protein regulator of protein phosphatase 2A (PP2A). It has been hypothesized that MID1 regulates PP2A, requiring the intermediary interaction with alpha4. Here we report that MID1 catalyzes the in vitro ubiquitination of the catalytic subunit of PP2A (PP2Ac) in the absence of alpha4. In the presence of alpha4, the level of PP2Ac ubiquitination is reduced. Using the MID1 RING-Bbox1-Bbox2 (RB1B2) construct containing the E3 ligase domains, we investigate the functional effects of mutations within the Bbox domains that are identified in patients with X-linked Opitz G syndrome (XLOS). The RB1B2 proteins harboring the C142S, C145T, A130V/T mutations within the Bbox1 domain and C195F mutation within the Bbox2 domain maintain auto-polyubiquitination activity. Qualitatively, the RB1B2 proteins containing these mutations are able to catalyze the ubiquitination of PP2Ac. In contrast, the RB1B2 proteins with mutations within the Bbox1 domain are unable to catalyze the polyubiquitination of alpha4. These results suggest that unregulated alpha4 may be the direct consequence of these natural mutations in the Bbox1 domain of MID1, and hence alpha4 could play a greater role to account for the increased amount of PP2A observed in XLOS-derived fibroblasts.

The roles of cohesins in mitosis, meiosis, and human health and disease

Mitosis and meiosis are essential processes that occur during development. Throughout these processes, cohesion is required to keep the sister chromatids together until their separation at anaphase. Cohesion is created by multiprotein subunit complexes called cohesins. Although the subunits differ slightly in mitosis and meiosis, the canonical cohesin complex is composed of four subunits that are quite diverse. The cohesin complexes are also important for DNA repair, gene expression, development, and genome integrity. Here we provide an overview of the roles of cohesins during these different events as well as their roles in human health and disease, including the cohesinopathies. Although the exact roles and mechanisms of these proteins are still being elucidated, this review serves as a guide for the current knowledge of cohesins.

Dental findings in Hamamy syndrome

This paper highlights features of dental rehabilitation of patients with Hamamy syndrome. A 10-year-old boy patient with Hamamy syndrome reported pain in the maxillary left central incisor, and all mandibular incisors. Intraoral clinical and radiographical examination showed enamel hypoplasia, severe dilacerated maxillary left central incisor and mandibular incisors, malocclusion, delayed eruption of teeth, taurodontism, and loss of lamina dura. Root canal treatment, strip crown and composite restorations were performed.

Cohesinopathies of a feather flock together

Roberts Syndrome (RBS) and Cornelia de Lange Syndrome (CdLS) are severe developmental maladies that present with nearly an identical suite of multi-spectrum birth defects. Not surprisingly, RBS and CdLS arise from mutations within a single pathway--here involving cohesion. Sister chromatid tethering reactions that comprise cohesion are required for high fidelity chromosome segregation, but cohesin tethers also regulate gene transcription, promote DNA repair, and impact DNA replication. Currently, RBS is thought to arise from elevated levels of apoptosis, mitotic failure, and limited progenitor cell proliferation, while CdLS is thought to arise, instead, from transcription dysregulation. Here, we review new information that implicates RBS gene mutations in altered transcription profiles. We propose that cohesin-dependent transcription dysregulation may extend to other developmental maladies; the diagnoses of which are complicated through multi-functional proteins that manifest a sliding scale of diverse and severe phenotypes. We further review evidence that cohesinopathies are more common than currently posited.

The non-redundant function of cohesin acetyltransferase Esco2: some answers and new questions

Cohesin and cohesin regulatory proteins function in an essential pathway enabling proper cohesion and segregation of sister chromatids. Additionally, these proteins are involved in double-strand break (DSB) repair and transcriptional regulation. Mutations in Establishment of cohesion 1 homolog 2 (Esco2), an evolutionary conserved cohesin acetyltransferase, are the cause of Roberts syndrome (RBS), a human congenital disorder. To explore the mechanism by which the deficiency in Esco2 affects cohesin's functions, we generated a mouse harboring a conditional Esco2 allele. To our surprise and in marked contrast to RBS, mouse Esco2 turns out to be a cell viability factor, the absence of which results in severe chromosome segregation defects and apoptosis. We found that the acetylation of the cohesin subunit Smc3 is significantly reduced in Esco2-deficient cells resulting in a marked reduction of Sororin recruitment to several, but not all cohesin bound loci. Here, we provide evidence that Esco2 is also required for DSB repair, which is consistent with previous studies in RBS cells.

A zebrafish model of Roberts syndrome reveals that Esco2 depletion interferes with development by disrupting the cell cycle

The human developmental diseases Cornelia de Lange Syndrome (CdLS) and Roberts Syndrome (RBS) are both caused by mutations in proteins responsible for sister chromatid cohesion. Cohesion is mediated by a multi-subunit complex called cohesin, which is loaded onto chromosomes by NIPBL. Once on chromosomes, cohesin binding is stabilized in S phase upon acetylation by ESCO2. CdLS is caused by heterozygous mutations in NIPBL or cohesin subunits SMC1A and SMC3, and RBS is caused by homozygous mutations in ESCO2. The genetic cause of both CdLS and RBS reside within the chromosome cohesion apparatus, and therefore they are collectively known as "cohesinopathies". However, the two syndromes have distinct phenotypes, with differences not explained by their shared ontology. In this study, we have used the zebrafish model to distinguish between developmental pathways downstream of cohesin itself, or its acetylase ESCO2. Esco2 depleted zebrafish embryos exhibit features that resemble RBS, including mitotic defects, craniofacial abnormalities and limb truncations. A microarray analysis of Esco2-depleted embryos revealed that different subsets of genes are regulated downstream of Esco2 when compared with cohesin subunit Rad21. Genes downstream of Rad21 showed significant enrichment for transcriptional regulators, while Esco2-regulated genes were more likely to be involved the cell cycle or apoptosis. RNA in situ hybridization showed that runx1, which is spatiotemporally regulated by cohesin, is expressed normally in Esco2-depleted embryos. Furthermore, myca, which is downregulated in rad21 mutants, is upregulated in Esco2-depleted embryos. High levels of cell death contributed to the morphology of Esco2-depleted embryos without affecting specific developmental pathways. We propose that cell proliferation defects and apoptosis could be the primary cause of the features of RBS. Our results show that mutations in different elements of the cohesion apparatus have distinct developmental outcomes, and provide insight into why CdLS and RBS are distinct diseases.

Control of mTORC1 signaling by the Opitz syndrome protein MID1

Mutations in the MID1 gene are causally linked to X-linked Opitz BBB/G syndrome (OS), a congenital disorder that primarily affects the formation of diverse ventral midline structures. The MID1 protein has been shown to function as an E3 ligase targeting the catalytic subunit of protein phosphatase 2A (PP2A-C) for ubiquitin-mediated degradation. However, the molecular pathways downstream of the MID1/PP2A axis that are dysregulated in OS and that translate dysfunctional MID1 and elevated levels of PP2A-C into the OS phenotype are poorly understood. Here, we show that perturbations in MID1/PP2A affect mTORC1 signaling. Increased PP2A levels, resulting from proteasome inhibition or depletion of MID1, lead to disruption of the mTOR/Raptor complex and down-regulated mTORC1 signaling. Congruously, cells derived from OS patients that carry MID1 mutations exhibit decreased mTORC1 formation, S6K1 phosphorylation, cell size, and cap-dependent translation, all of which is rescued by expression of wild-type MID1 or an activated mTOR allele. Our findings define mTORC1 signaling as a downstream pathway regulated by the MID1/PP2A axis, suggesting that mTORC1 plays a key role in OS pathogenesis.

Hypospadias associated with hypertelorism, the mildest phenotype of Opitz syndrome

Hypospadias is a common congenital malformation in boys in which the urethral meatus opens on the underside of the penis. It is considered a complex disorder with several genes involved and the molecular etiology is just beginning to be revealed. As more than 85% of Opitz G/BBB syndrome (OS) patients with MID1 mutations are manifested with hypospadias, we have investigated the association between the MID1 gene and hypospadias. DNA from 114 hypospadias cases was analyzed with direct sequencing of the MID1 gene. Genotyping analysis was performed for the single-nucleotide polymorphism (SNP) c.1230G>A in 370 individuals with varying degrees of hypospadias and compared with 759 healthy controls. We identified one nonsense mutation c.712G>T (p.E238X), one missense mutation c.1679A>G (p.K560R) and two synonymous variants c.1230G>A (p.S410S) and c.1284T>G (p.V428V). We also detected a significant difference in the rare allele frequency of SNP c.1230G>A in hypospadias patients as compared with controls (P=0.016). Our finding suggests that hypospadias associated with hypertelorism is the mildest phenotype in OS caused by MID1 mutations.

A MID1 mutation associated with reduced penetrance of X-linked Opitz G/BBB syndrome

The X-linked Opitz G/BBB syndrome (OS) is a congenital malformation disorder characterized by hypertelorism, swallowing difficulties, hypospadias, and additional midline malformations. Loss of function mutations in the MID1 gene at Xp22.3 are responsible for the X-linked form of OS. Various mutations are found all over the gene but without a clear genotype-phenotype correlation. We describe additional family studies of a previously reported boy with a relatively mild form of OS, caused by the unique p.Lys370Glu (c.1108A>G) mutation in MID1. The same mutation was found in his clinically affected brother but also in the healthy maternal uncle. To our knowledge, this is the first report of a MID1 missense mutation causing non-penetrance in a male.

Midline craniofacial defects and morning glory disc anomaly. A distinct clinical entity

A case with a severe midline craniofacial defect, comprising a midline cleft lip and palate with a sphenoethmoidal encephalocele, hypertelorism, bilateral dysplastic optic discs and agenesis of the corpus callosum is described. The optic discs are consistent with the spectrum of appearances seen in the Morning Glory Disc Anomaly (MGDA). This anomaly is usually a uniocular problem that may be rarely associated with craniofacial abnormalities. Despite this range of abnormalities this child was developing well with a specific motor delay at the age of eight months. Cases with similar midline craniofacial abnormalities from the literature are reviewed. This condition appears to be a distinct entity within the spectrum of frontonasal dysplasia.

Atypical midline cleft with duplication of the metopic suture

INTRODUCTION

In contrast to the common clefts of the lip, alveolus and palate, the atypical clefts of the face may come in myriad patterns of clinical expression and are often not easy to define.

PURPOSE

In this report, a case of median craniofacial dysraphia is described.

PATIENT

At presentation, the 3-month-old male patient had a bilateral complete cleft of the lip, alveolus and palate. The nose was wide and a horn was present on the nasal dorsum. 3-D CT AND MRI REVEALED: Duplication of the metopic suture ending at the wide anterior fontanel; orbital hypertelorism; midline cranial cleft ending just superior to the nasal dorsum; frontoethmoidal encephalocoele and holoprosencephaly. The presence of two metopic sutures was confirmed during surgery.

CONCLUSION

The presented case carries the characteristics of the median cleft face syndrome. However, it differs from similar cases in two respects. First, the patient had two metopic sutures, one on either side of the cranial extension of the median cleft. Second, the patient had a bilateral cleft lip in contrast to the expected median cleft lip deformity.

Asymmetrical skull, ptosis, hypertelorism, high nasal bridge, clefting, umbilical anomalies, and skeletal anomalies in sibs: is Carnevale syndrome a separate entity?

A group of syndromes, consisting of Malpuech syndrome, Michels syndrome, Carnevale syndrome, OSA syndrome, and Mingarelli syndrome share the combination of symptoms of highly arched eyebrows, ptosis, and hypertelorism, and vary in other symptoms such as asymmetry of the skull, eyelid, and anterior chamber anomalies, clefting of lip and palate, umbilical anomalies, and growth and cognitive development. It has been suggested that they are in fact part of the same entity. Here, we describe a brother and sister with the same constellation of symptoms, and compare these with the various entities. We conclude that the present patients resemble most patients with Carnevale and Mingarelli syndrome, and the case reported by Guion-Almeida, and that these patients form together most probably the same entity. We suggest the name Carnevale syndrome as this author described this combination of symptoms for the first time. Malpuech and Michels syndromes are probably separate entities, although they may still be allelic. Pattern of inheritance of Carnevale syndrome is most likely autosomal recessive.

EFNB1 mutation at the ephrin ligand-receptor dimerization interface in a patient with craniofrontonasal syndrome

Craniofrontonasal syndrome (CFNS) is characterized by craniosynostosis, hypertelorism, a broad nasal tip and occasionally cleft lip and palate, and is caused by a mutation in the ephrin-B1 gene (EFNB1). The study of naturally occurring human EFNB1 mutations offers a unique opportunity to better define the critical portion within the ephrin domain that is essential for the function of EFNB1 protein in craniofacial development. Here, we report a CFNS patient with a novel EFNB1 missense mutation present at the interface between EFNB1 and its receptor proteins. The patient's facial features included hypertelorism, a broad nasal tip, brachycephaly, frontal bossing, facial asymmetry and esotropia. In addition, she had pectus carinatum, grooved nails on her thumb, an abnormal palmar crease pattern and a broad first toe. Her development was appropriate for her age. Direct sequencing of polymerase chain reaction products using an autosequencer revealed a heterozygous missense mutation, Ser118Ile. Ser118 is located in the G-H loop of the extracellular ephrin domain and is highly evolutionarily conserved among rodents, avians and fish. The mutation occurred de novo and was not present in 100 normal Japanese control subjects. Substitutions of the adjacent amino acid residue, Pro119, have been previously reported in three CFNS patients. Since the structure of EFNB1 is not yet available, the spatial locality of Ser118 was characterized using the protein structure of EFNB2. We deduced that Ser118 in EFNB1 resides at the major dimerization interface with Eph receptors and inferred that the Ser118Ile mutation may impede the protrusion of the G-H loop, thereby disturbing Eph-Ephrin signal transduction.

Malpuech syndrome: broadening the clinical spectrum and molecular analysis by array-CGH

We report on a patient with mental and growth retardation, bilateral cleft lip and palate, hypertelorism, ptosis, hearing loss and mild epispadias, suggestive of Malpuech syndrome. High-resolution karyotype and microarray-CGH using an oligonucleotide array with 75Kb oligo's were normal, excluding Wolf-Hirschhorn syndrome. Long-term follow-up revealed psychiatric manifestations starting at young age.

Neonatal teeth in X-linked Opitz (G/BBB) syndrome

Two male siblings are described with a clinical and molecular diagnosis of X-linked Opitz (G/BBB) syndrome and the previously unreported feature of neonatal mandibular incisors.

A longitudinal study on influence of primary facial deformities on maxillofacial growth in patients with cleft lip and palate

OBJECTIVE

The goal of this study was to use three-dimensional (3D) analysis to characterize the primary facial deformities in children with unilateral cleft lip and palate (UCLP) and then serially analyze the relationships between facial deformities and maxillofacial growth from infancy to adolescence.

PARTICIPANTS

Twenty-one Japanese subjects with unilateral cleft lip and alveolus (UCLA) and 20 with UCLP who had been operated on and then followed up for more than 15 years were enrolled in this study.

MAIN OUTCOME MEASURES

Facial cast models taken at cheiloplasty were scanned with a 3D laser scanner. Lateral cephalographs taken when subjects were 15 years of age or older were traced, and linear and angular measurements were calculated. The correlation between primary facial forms and maxillofacial morphology in adolescence was analyzed.

RESULTS

Three-dimensional analysis showed larger ocular hypertelorism, wider cleft, greater deviation of the columella base, and more severe retruded position of the affected nasal alar base in subjects with UCLP than those with UCLA. Total surface area of the upper lips in subjects with UCLP was significantly smaller than those with UCLA. Correlation analyses revealed that the width of cleft lip, deviation of the columella base, difference of the nose base width, and surface area of the upper lip were statistically correlated with the maxillary length, the anterior position of the maxillary alveolar base, the posterior facial height, and the high angle of the mandible.

CONCLUSION

The subjects who had less severe facial deformities and more tissue volume of the upper lips at cheiloplasty showed better maxillofacial growth.

Clinical variation of Aarskog syndrome in a large family with 2189delA in the FGD1 gene

The clinical diagnosis of ASS (Aarskog-Scott syndrome or Faciogenital Dysplasia) was made in seven individuals belonging to a large Arabic family, which was supported by molecular studies revealing a 2189delA mutation in exon 15 of the FDG1 gene. The affected individuals in this family demonstrated clinical variability particularly in their cognitive skills, raising the question whether other genetic factors might be involved in the phenotypic evolution of ASS.

New cases of Bohring–Opitz syndrome, update, and critical review of the literature

We report on four additional unrelated cases of Bohring-Opitz syndrome with the highly characteristic phenotype of facial anomalies including bulging forehead over the metopic suture, frontal nevus flammeus, exophthalmos, hypertelorism, upslanting palpebral fissures, and cleft lip and/or palate, as well as flexion deformities of the upper limbs, multiple other anomalies, and severe failure to thrive. We also update the clinical outcome of the patients reported in the original article by Bohring et al. [Am J Med Genet 85:438-446] and critically review the subsequently published cases considered to have Bohring-Opitz syndrome.

Terminal deletion of 6p results in a recognizable phenotype

With improved cytogenetic techniques, small deletions and duplications are being identified with increased frequency. We report four cases with terminal deletions involving the 6p24- and 6p25-pter chromosomal segment who exhibit a distinct, recognizable pattern of malformations including hypertelorism, downslanting palpebral fissures, flat nasal bridge, Dandy-Walker malformation/variant, congenital heart defects, anterior eye-chamber abnormalities, hearing loss, and developmental delay. We also compare the clinical aspects of these patients to those of previously reported cases in the literature with similar terminal deletions of chromosome 6p. Routine chromosome analysis can miss this deletion, therefore, high-resolution chromosome analysis is indicated for individuals who exhibit these distinct features. Furthermore, individuals with this deletion should have an ophthalmologic exam, cardiac evaluation, head imaging, renal ultrasound, and formal hearing evaluation.

Dysmorphology and the orbital region: a practical clinical approach

Dysmorphology is the field of medicine focusing on congenital developmental abnormalities due to exogenous teratogens, chromosomal anomalies, or to a defect in a single gene. Numerous syndromes have been reported and a growing number of genes or chromosomal anomalies are identified. The clinical observation of the face remains an essential part of the clinical evaluation of the patients. The orbital region, as other regions of the face, should be systematically evaluated. Orbital malformations can be isolated or part of a syndrome. In the diagnostic process, the orbital anomaly can be classified as a major feature (essential for the diagnosis), a moderate feature (important but not essential for the diagnosis), or a minor feature (contributing weakly to the diagnosis). The diagnoses of the main orbital anomalies in dysmorphology are reviewed and illustrated with relevant examples of syndromes that are presented as well as the usual landmarks used in clinical practice. Abnormal position of the eyes in syndromes such as hypertelorism, hypotelorism, primary or secondary telecanthus, asymmetry, and proptosis are discussed. Eyelid anomalies, such as cryptophthalmos, ablepharon, blepharophimosis, euryblepharon, or anomalies at the level of the eyelashes and eyebrows are described.

Michels syndrome, Carnevale syndrome, OSA syndrome, and Malpuech syndrome: Variable expression of a single disorder (3MC syndrome)?

We report on a 3-year-old girl with Michels syndrome, a rare condition characterized by craniosynostosis, blepharophimosis, ptosis, epicanthus inversus, cleft lip/palate, abnormal supra-umbilical abdominal wall, and mental deficiency. The phenotypic findings are compared with the six previously reported Michels cases, and with patients referred to as Carnevale, OSA, and Malpuech syndromes. Michels syndrome is characterized by cleft lip and palate, anterior chamber anomalies, blepharophimosis, epicanthus inversus, and craniosynostosis. Carnevale syndrome shows hypertelorism, downslanting palpebral fissures, ptosis, strabismus synophrys, large and fleshy ears, and lozenge-shaped diastasis around the umbilicus. OSA syndrome resembles Carnevale, with humeroradial synostoses, and spinal anomalies as extra features. Malpuech syndrome shows IUGR, hypertelorism, cleft lip and palate, micropenis, hypospadias, renal anomalies, and caudal appendage. All are autosomal recessive. Despite the presence of apparently distinctive key features, it appears that these four entities share multiple similarities in the facial Gestalt and the pattern of MCA. Those similarities lead us to postulate that they belong to the same spectrum, which could be referred to as "3MC syndrome" (Malpuech-Michels-Mingarelli-Carnevale syndrome).

Normal values of medial and lateral canthal distances in 3 to 18 year-old Nigerians

BACKGROUND

This study was carried out on male and female Nigerians whose age ranged from 3 to 18 years in order to provide a database of canthal measurements for a predominantly black population and compare them with Caucasians.

STUDY DESIGN

All the healthy pupils and students were randomly selected. The ages of the children, adolescents and young adults were approximated to their nearest birthdays. Two different researchers measured each parameter and the mean values were recorded.

SETTING

Nursery, primary, secondary schools and the University of Benin, in Benin City, Nigeria.

RESULTS

Four hundred and sixty eight males (53.4%) and 408 (46.6%) females making up a total of 876 subjects were studied. The mean values for medial canthal distance for male Nigerians are slightly higher than those established for male Caucasians and these differences are significant (p>0.05). There was no significant difference in the lateral canthal distance between the two groups (p<0.05). Nigerian and Caucasian females have significant difference (p>0.05) in mean values for medial canthal distances but not in lateral canthal distance (p<0.05). The difference in these distances between Nigerian males and females are not significant. Weight and lateral canthal distance showed a covariance of 6.980 while age and lateral canthal distance, age and medial canthal distance showed a covariance of 2.970 and 1.140 respectively. There was no correlation between age, height, weight and the distances measured.

CONCLUSION

Medial canthal distances between male and female Nigerians compared to males and female Caucasians show significant variations but not in the lateral canthal distances.

Segregation of a t(1;3) translocation in multiple affected family members with both types of adjacent-1 segregants

A subtle balanced translocation involving the terminal regions of 1q and 3p was identified in a large family by high-resolution karyotype analysis and confirmed by fluorescence in situ hybridization (FISH) analysis. In this family, segregation of a balanced t(1:3)(q42.3;p25) chromosome translocation led to two types of viable unbalanced complements. The proband inherited the derivative chromosome 3, resulting in partial trisomy of 1q and partial monosomy of 3p. A paternal uncle and cousin had the reciprocal rearrangement with a derivative of chromosome 1, resulting in partial monosomy for 1q and partial trisomy for 3p. While profound mental and physical retardation and congenital heart defects were characteristics for both rearrangements, facial dysmorphism was quite distinct for each imbalance. Individuals who had the derivative chromosome 3 had a long face, wide eyebrows, small palpebral fissures, hypertelorism, prominent glabella, a large tip of the nose, long philtrum with thin upper lip, and low set-ears. In contrast, family members with the derivative of chromosome 1 had a tall forehead with bifrontal narrowing, full and large cheeks, and large simple ears. Since the translocated segments are small and approximately equal in size in this family, it is not surprising that viability was seen in individuals with both types of adjacent-1 segregation. In this kindred, the ratio of normal to abnormal individuals born to balanced carriers is believed to be about 1:1.5. This suggests that the recurrence risk for carriers is 50%.

A newly recognized syndrome with double upper and lower lip, hypertelorism, eyelid ptosis, blepharophimosis, and third finger clinodactyly

Congenital double lip is an uncommon developmental abnormality usually affecting the upper lip. We report a 21-year-old male with double upper and lower lip, hypertelorism, unilateral ptosis, blepharophimosis, and broad nose with broad nasal tip, highly arched palate, and bilateral third finger clinodactyly. The disorder differs from Ascher syndrome and appears to represent a newly recognized syndrome.

Clinical and molecular delineation of the Greig cephalopolysyndactyly contiguous gene deletion syndrome and its distinction from acrocallosal syndrome

Greig cephalopolysyndactyly syndrome (GCPS) is caused by haploinsufficiency of GLI3 on 7p13. Features of GCPS include polydactyly, macrocephaly, and hypertelorism, and may be associated with cognitive deficits and abnormalities of the corpus callosum. GLI3 mutations in GCPS patients include point, frameshift, translocation, and gross deletion mutations. FISH and STRP analyses were applied to 34 patients with characteristics of GCPS. Deletions were identified in 11 patients and the extent of their deletion was determined. Nine patients with deletions had mental retardation (MR) or developmental delay (DD) and were classified as severe GCPS. These severe GCPS patients have manifestations that overlap with the acrocallosal syndrome (ACLS). The deletion breakpoints were analyzed in six patients whose deletions ranged in size from 151 kb to 10.6 Mb. Junction fragments were found to be distinct with no common sequences flanking the breakpoints. We conclude that patients with GCPS caused by large deletions that include GLI3 are likely to have cognitive deficits, and we hypothesize that this severe GCPS phenotype is caused by deletion of contiguous genes.

Teebi hypertelorism syndrome

Teebi (1987) described an autosomal dominant syndrome with resemblance to craniofrontonasal dysplasia. Here we present a 2 year 5 month old girl with Teebi syndrome showing a prominent forehead, hypertelorism, mild exophthalmos, downslanting palpebral fissures, a depressed nasal bridge, a broad nasal tip, a long philtrum, natal teeth, a thin upper lip, an everted lower lip, a small chin, low-set ears, preauricular fistulas, a short neck, mild pectus excavatum, an umbilical hernia, clinodactyly of the 5th fingers with mild radial deviation of the distal phalanges of the middle fingers, mild pes adductus, an ectopic kidney, and normal psychomotor development. Her mother and her grandmother had similar features.

Is it a new syndrome or a clinical variability in cerebro-oculo-nasal syndrome?

We present a male infant 2.5-months old with asymmetric skull, anophthalmia, apparent hypertelorism, abnormal nares, unilateral cleft lip and palate, and structural abnormalities of the central nervous system. These findings are similar to cerebro-oculo-nasal syndrome except for the appearance of nose. This case is either a clinical variability in cerebro-oculo-nasal syndrome or a new entity.

X-linked Opitz syndrome: novel mutations in the MID1 gene and redefinition of the clinical spectrum

Opitz (or G/BBB) syndrome is a pleiotropic genetic disorder characterized by hypertelorism, hypospadias, and additional midline defects. This syndrome is heterogeneous with an X-linked (XLOS) and an autosomal dominant (ADOS) form. The gene implicated in the XLOS form, MID1, encodes a protein containing a RING-Bbox-Coiled-coil motif belonging to the tripartite motif (TRIM) family. To further clarify the molecular basis of XLOS, we have undertaken mutation analysis of the MID1 gene in patients with Opitz syndrome (OS). We found novel mutations in 11 of 63 male individuals referred to us as sporadic or familial X-linked OS cases. The mutations are scattered throughout the gene, although more are represented in the 3' region. By reviewing all the MID1-mutated OS patients so far described, we confirmed that hypertelorism and hypospadias are the most frequent manifestations, being present in almost every XLOS individual. However, it is clear that laryngo-tracheo-esophageal (LTE) defects are also common anomalies, being manifested by all MID1-mutated male patients. Congenital heart and anal abnormalities are less frequent than reported in literature. In addition, we can include limb defects in the OS clinical synopsis as we found a MID1-mutated patient showing syndactyly. The low frequency of mutations in MID1 and the high variability of the phenotype suggest the involvement of other genes in the OS phenotype.

Teebi hypertelorism syndrome: additional cases

We report on two unrelated Brazilian boys who have craniofacial and digital anomalies resembling those reported with Teebi hypertelorism syndrome. Additional features such as cleft lip and palate, large uvula, atypical chin and abnormal scapulae were observed.

Guadalajara camptodactyly type III: a new probably autosomal dominant syndrome

A Mexican family is presented with the main clinical features of camptodactyly, a distinctive facial appearance because of ocular hypertelorism, telecanthus, symblepharon and spinal defects. Other clinical manifestations included: multiple nevi, simplified ears, retrognathia, congenital shortness of the sternocleidomastoid muscle, thin hands and feet, a small penis and mild mental retardation. Radiographic studies revealed spina bifida occulta at cervical and dorso-lumbar levels, increased bone trabeculae, cortical thickening and delayed bone age. The presence of five affected members through four generations suggests autosomal dominant inheritance although no male-to-male transmission was documented. The authors propose this as a new entity, and have designated it Guadalajara camptodactyly type III.

Food aversion and facial dysmorphism--a newly described syndrome?

We report three children with food aversion and characteristic facial dysmorphism, long digits and genitourinary abnormality. Interrogation of the London Dysmorphology Database suggests that this is a previously unreported syndrome.

Association of external auditory canal atresia, vertical talus, and hypertelorism: confirmation of Rasmussen syndrome

In 1979, Rasmussen et al. reported six members of a family with congenital, bilateral, symmetrical, and isolated subtotal atresia of the external auditory canal, bilateral foot abnormalities, and increased interocular distance. The family history suggested autosomal dominant inheritance of the syndrome. We report a 3-year-old girl whose symptoms are compatible with this diagnosis. Therefore, we suggest confirmation of the description by Rasmussen et al. as a distinct entity and suggest the term Rasmussen syndrome for this condition.

Roberts syndrome, normal cell division, and normal intelligence

Roberts-SC phocomelia syndrome (RS) is an autosomal recessive disorder of symmetric limb defects, craniofacial abnormalities, pre- and postnatal growth retardation, and mental retardation. Patients with RS have been reported to have premature separation of heterochromatin of many chromosomes and abnormalities in the cell-division cycle. No case has been reported who had normal intelligence and normal cell division with typical clinical features of the RS. We report a case of a six-year-old male of clinical and radiologic findings of typical RS with normal cell division and normal intelligence. Although he showed growth retardation, his intelligence was normal. Van Den Berg and Francke later reported that 79 out of 100 cases of Roberts syndrome had premature cell separation (PCS). We think that this case may demonstrate severe expression of the Roberts syndrome even though PCS is not exhibited. The limb involvement of this case was symmetrical, and he showed phocomelia of upper limbs, equinus valgus deformity of ankle, aplasia of fibula, and shortness of fifth toes while his hands and feet were normal with 5 rays each. Craniofacial abnormalities of this case were typical; he showed scaphocephaly, mild hypertelorism, mandibular hypoplasia, dysplastic helix of ear, narrowing of external auditory canal, and cleft palate with wide gap. This report supports the theory that normal intelligence can make social-personal adjustment possible even if all of the stigmata of Roberts syndrome is present.

Schinzel-Giedion syndrome: interesting facial and orodental features, and dental management

Schinzel-Giedion syndrome comprises multiple congenital anomalies. The orofacial features include coarse facies, frontal bossing, ocular hypertelorism, anterior open bite and macrodontia. Two cases are presented in which the presence of specific craniofacial anomalies with bilateral hydronephrosis confirmed the diagnosis. In one patient, bottle-feeding was associated with caries in maxillary central and lateral incisors, but the second patient was permanently tube fed and did not experience any dental caries. Clinical management of these patients requires a coordinated approach from a team of medical and dental specialists.

Interpupillary index: a new parameter for hypo-hypertelorism

AIM

To establish a new clinical index to evaluate the presence of hypo-hypertelorism with greater accuracy.

MATERIAL AND METHODS

After screening a wide range of population, 310 elementary school children (185 boys, 125 girls) aged 7-15 years were included in this study. For this cross-sectional study, a millimetre ruler was used. The anatomical interpupillary distance was measured by a modified Viktorin's method. In addition, inner and outer intercanthal distances were obtained. The data were analyzed by Student's t-test for two independent samples using SPSS for Windows. There were children with clinical hypertelorism (n = 92, group 1), children with large fronto-occipital circumference (FOC) (n = 101, group 2), and age- and sex-matched normal controls (n = 117, group 3). Due to variations in FOC among healthy subjects, we introduced a new practical concept for evaluation of interpupillary distance, namely the interpupillary index, the simple product obtained by dividing the interpupillary distance by the FOC, multiplied by 100.

RESULTS

The overall idiopathic benign macrocephalic children (group 2) had significantly (p < 0.001) larger interpupillary distances (6.13 +/- 0.36 cm) and FOCs (56.99 +/- 1.46 cm) than those of normal controls (5.70 +/- 0.26cm and 52.82 +/- 1.22 cm, respectively). But, the difference between the combined product of interpupillary distance and FOC, the interpupillary index, was not significant (10.76 +/- 0.50 and 10.79 +/- 0.35, respectively) (p > 0.05). On the other hand, the children with hypertelorism had significantly (p < 0.001) larger interpupillary distances (6.47 +/- 0.29cm) and FOCs (54.90 +/- 2.18cm) when compared with the controls. In addition, the interpupillary index was significantly (p < 0.001) higher (11.80 +/- 0.45) than both macrocephalic children (10.76 +/- 0.50) and controls (10.79 +/- 0.35). Intercanthal distances and intercanthal index of hyperteloric children were also significantly (p<0.001) larger than both macrocephalic children and controls.

CONCLUSION

This new index offers a new concept for more accurate evaluation of the presence of ocular hypo-hypertelorism.

A case of false median cleft of upper lip with IV-A holoprosencephaly that underwent cheiloplasty at 2.5 years of age

Holoprosencephaly results from the incomplete development of midline structures within the cerebrum and encompasses a series of abnormalities of mid-facial development. Here, we report a case of male holoprosencephaly associated with false median cleft of upper lip. This patient belonged clinically to the DeMyer's group IV holoprosencephaly, semilobar type. An infant with this type of holoprosencephaly has been thought to die generally within 1 to 2 years after birth and to rarely benefit from an operation. In this case, the patient had cheiloplasty at the age of 2.5 years at the request of his parents and he lives currently, being 3 years and 2 months old.

Hirschsprung disease, mental retardation and dysmorphic facial features in five unrelated children

We report five patients with Hirschsprung disease, severe mental retardation and dysmorphic facial features including hypertelorism, prominent forehead and dysmorphic ears. All four boys had hypospadias. All had postnatally retarded growth. One of them had a de novo apparently balanced translocation 46,XY,t(2;11)(q22.2;q21). There are several reports on patients with Hirschsprung disease, mental retardation and various dysmorphic features. Some of them, especially those reported by Tanaka et al. [(1993) Pediatr Neurol 9:479-481], Lurie et al. [(1994) Genet Couns 5:11-14] and Mowat et al. [(1998) J Med Genet 35:617-623] closely resemble our patients suggesting that they have the same malformation syndrome.

Normative values of craniofacial measurements in idiopathic benign macrocephalic children

OBJECTIVE

To determine normal standard values at each age for head circumference; inner canthal distance; outer canthal distance; near interpupillary distance; distant [far] interpupillary distance; canthal index; and circumference-interorbital index specific for the age, sex, and race in 7- to 16-year-old idiopathic benign macrocephalic male and female children.

METHODS

The measurements of head circumference were obtained in 8736 children (4591 boys and 4145 girls) in the city center of Malatya. From these, macrocephalic children (boys = 103, girls = 93) were chosen and invited to our clinic for detailed examination. Mean values for each parameter were obtained at each age from 7 to 16 years.

RESULTS

The mean age for male and female children were 11.87 +/- 2.87 and 11.72 +/- 2.75 years, respectively. The overall mean values for head circumference, inner canthal distance, outer canthal distance, near interpupillary distance, distant interpupillary distance, canthal index and circumference-interorbital index in boys were found to be 57.43 +/- 1.46 cm, 31.90 +/- 2.41 mm, 89.29 +/- 4.34 mm, 58.79 +/- 2.97 mm, 62.10 +/- 3.23 mm, 35.73 +/- 2.24, and 5.56 +/- 0.44, respectively. In girls, these values were 56.57 +/- 1.24 cm, 31.45 +/- 2.65 mm, 87.71 +/- 4.11 mm, 58.16 +/- 3.46 mm, 61.26 +/- 3.66 mm, 35.84 +/- 2.31, and 5.56 +/- 0.43, respectively.

CONCLUSION

Normal values of craniofacial measurements for idiopathic benign macrocephalic healthy children are useful in early identification of some craniofacial syndromes, congenital or posttraumatic telecanthus, epicanthus, and hypo-hypertelorism and of planning surgical intervention. We suggest that the comparison of craniofacial dimensions of macrocephalic healthy children must be performed with normal standards specific for age as well as sex and race.