Familial hemifacial microsomia due to autosomal dominant inheritance. Case reports

Haploinsufficiency of SF3B2 causes craniofacial microsomia

Craniofacial microsomia (CFM) is the second most common congenital facial anomaly, yet its genetic etiology remains unknown. We perform whole-exome or genome sequencing of 146 kindreds with sporadic (n = 138) or familial (n = 8) CFM, identifying a highly significant burden of loss of function variants in SF3B2 (P = 3.8 × 10^-10), a component of the U2 small nuclear ribonucleoprotein complex, in probands. We describe twenty individuals from seven kindreds harboring de novo or transmitted haploinsufficient variants in SF3B2. Probands display mandibular hypoplasia, microtia, facial and preauricular tags, epibulbar dermoids, lateral oral clefts in addition to skeletal and cardiac abnormalities. Targeted morpholino knockdown of SF3B2 in Xenopus results in disruption of cranial neural crest precursor formation and subsequent craniofacial cartilage defects, supporting a link between spliceosome mutations and impaired neural crest development in congenital craniofacial disease. The results establish haploinsufficient variants in SF3B2 as the most prevalent genetic cause of CFM, explaining ~3% of sporadic and ~25% of familial cases.

Treatment of hemifacial microsomia in a growing child: the importance of co-operation between the orthodontist and the maxillofacial surgeon

The treatment of patients with hemifacial microsomia (HM) always requires an interdisciplinary approach including at least maxillofacial surgery and orthodontics. Co-operation not only within the team, but also with the patients and their family is essential in order to achieve the best results. In the case history of the 10-(1/2) year old female patient reported here, three surgical interventions (two with costo-chondral bone grafts) and a 3-year orthodontic treatment have taken place. A harmonious facial and occlusal result was finally reached.

A Lebanese family with autosomal recessive oculo-auriculo-vertebral (OAV) spectrum and review of the literature: is OAV a genetically heterogeneous disorder?

Oculo-auriculo-vertebral (OAV) spectrum summarizes a continuum of ocular, auricular, and vertebral anomalies. Goldenhar syndrome is a variant of this spectrum and is characterized by pre-auricular skin tags, microtia, facial asymmetry, ocular abnormalities, and vertebral anomalies of different sizes and shapes. Most cases are thought to be sporadic. However, a few families were reported to have an autosomal recessive inheritance and other families' presentation of the syndrome strongly supported an autosomal dominant inheritance. We report OAV in a female infant presenting with tracheomalacia, diaphragmatic hernia, encephalomeningocele, sacral neural tube defect, and cardiac defect and her brother having no more than dysmorphic features. The mode of inheritance in this family supports an autosomal recessive inheritance where the transmission was from normal first-degree consanguineous parents to one of the sons and to the daughter. This report further broadens the clinical presentation and symptoms of OAV and supports the hypothesis advancing OAV as a genetically heterogeneous disorder.

Spatio-temporal dynamics of gene expression of the Edn1-Dlx5/6 pathway during development of the lower jaw

The morphogenesis of the vertebrate skull results from highly dynamic integrated processes involving the exchange of signals between the ectoderm, the endoderm, and cephalic neural crest cells (CNCCs). Before migration CNCCs are not committed to form any specific skull element, molecular signals exchanged in restricted regions of tissue interaction are crucial in providing positional identity to the CNCCs mesenchyme and activate the specific morphogenetic process of different skeletal components of the head. In particular, the endothelin-1 (Edn1)-dependent activation of Dlx5 and Dlx6 in CNCCs that colonize the first pharyngeal arch (PA1) is necessary and sufficient to specify maxillo-mandibular identity. Here, to better analyze the spatio-temporal dynamics of this process, we associate quantitative gene expression analysis with detailed examination of skeletal phenotypes resulting from combined allelic reduction of Edn1, Dlx5, and Dlx6. We show that Edn1-dependent and -independent regulatory pathways act at different developmental times in distinct regions of PA1. The Edn1-->Dlx5/6-->Hand2 pathway is already active at E9.5 during early stages of CNCCs colonization. At later stages (E10.5) the scenario is more complex: we propose a model in which PA1 is subdivided into four adjacent territories in which distinct regulations are taking place. This new developmental model may provide a conceptual framework to interpret the craniofacial malformations present in several mouse mutants and in human first arch syndromes. More in general, our findings emphasize the importance of quantitative gene expression in the fine control of morphogenetic events.

Hemifacial microsomia: a clinicoradiological report of three cases

Hemifacial microsomia is a congenital malformation in which there is deficiency in the amount of hard and soft tissues on one side of the face. It is primarily a syndrome of first and second branchial arches involving underdevelopment of the temporomandibular joint, mandibular ramus, masticatory muscles, ears and occasionally defects in facial nerve and muscles. Here, we report three cases of hemifacial microsomia diagnosed based on clinical and radiographic findings. All three cases had variable presentations ranging from the mildest form that included facial asymmetry and ear deformity to the most severe and unusual form with facial nerve paralysis and spine deformity.

Hemifacial microsomia: from gestation to childhood

Hemifacial microsomia (HFM) is a variable, complex malformation involving asymmetric hypoplasia of the face and ear. Little is known about the risk factors for or consequences of HFM. In this study, we describe 3 studies that have been or are currently being conducted to further our understanding of this malformation. The first completed study examined whether HFM risk is related to maternal exposures that may affect blood flow. In that case-control study, interview data from 230 mothers of children in the case group and 678 mothers of children in the control group suggested that maternal use of vasoactive medications in the first trimester, particularly in combination with cigarette smoking, was associated with increased risks of HFM. The second study is currently underway, in which we are evaluating whether HFM risk is related to genetic variation in pathways associated with vasculogenesis and hemostasis, using DNA collected in the first study. The third ongoing study observes children with HFM to identify psychosocial, cognitive, dental, and medical sequelae. When the children from the original case-control study are 6 or 7 years of age, mothers and teachers complete self-administered questionnaires that cover a wide range of psychosocial development domains. Preliminary analyses of 115 case and 314 control children suggest that children with HFM may have worse teacher-reported academic performance and possibly higher levels of internalizing behavior problems than control children. When data on the full study sample are available, further analyses will determine whether the preliminary findings remain and if they vary by HFM phenotype, parenting style, or indicators of social risk.

Oculoauriculovertebral spectrum: report of nine familial cases with evidence of autosomal dominant inheritance and review of the literature

Oculoauriculovertebral spectrum (OAVS; OMIM 164210) is a complex condition characterized by defects of aural, oral, mandibular and vertebral development. The aetiology of this condition is likely to be heterogeneous; most cases are sporadic, however, familial cases suggesting autosomal recessive and autosomal dominant inheritance have been reported. In this study, we describe the clinical aspects of nine familial cases with evidence of autosomal dominant inheritance and compare them with reports in the literature. Interfamilial and intrafamilial clinical variabilities were observed in this study (reinforcing the necessity of careful examination of familial members). We suggest that oculoauriculovertebral spectrum with autosomal dominant inheritance is characterized mainly by bilateral auricular involvement and rarely presents extracranial anomalies.

Review of the etiologic heterogeneity of the oculo-auriculo-vertebral spectrum (Hemifacial Microsomia)

Hemifacial microsomia is a congenital asymmetry of the lower face that may be associated with other cranial and extracranial anomalies. The variability of its severity, and wide range of anomalies that have been reported with it in some cases has resulted in these composite manifestations being given a number of names, including oculo-auriculo-vertebral spectrum (OAVS). Etiology is often stated to be a perturbation of embryonic blood flow in the developing region, although other factors may also play a role in some cases. Depending on what is considered to be minimum criteria for affected classification, what is often to be presumed to be a sporadic event in a family may be the more severe manifestation of a familial condition. Etiological factors are clearly heterogeneous, the investigation of which is confounded by not only the lack of a refined affected phenotype, but also the apparent influence of genetic factors in some instances that directly influence phenotype perhaps through alteration of mesodermal development, or indirectly through increased susceptibility to vascular disruption. Future studies likely to advance knowledge in this area will need to incorporate an analysis of who may be minimally affected in families, so that advances in genotyping will have greater power to distinguish genetic factors that may influence OVAS through interaction with environmental factors in particular families. The same genetic-environmental factors and or etiological mechanisms may then be investigated in apparently sporadic cases.

Morning glory anomaly with bilateral choroidal colobomas in a patient with Goldenhar's syndrome

A child with Goldenhar's syndrome, bilateral choroidal colobomas, and a morning glory anomaly of the optic disk in one eye is described. Bilateral posterior segment anomalies associated with Goldenhar's syndrome are rare. An association between the morning glory anomaly and Goldenhar's syndrome has not been previously reported.

A family with autosomal dominant oculo-auriculo-vertebral spectrum

Oculo-auriculo-vertebral spectrum (MIM 164210) is a term suggested by Gorlin to summarize the different phenotypic expressions of a continuum that has been known as hemifacial microsomia, Goldenhar syndrome, or first and second branchial arch anomalies. The different terms indicate the extremely variable clinical findings, including especially defects of aural, oral and mandibular development. Additionally, cardiac, renal, skeletal and other anomalies occur. The majority of oculo-auriculo-vertebral spectrum cases are sporadic; nevertheless, several families have been reported with proof of both autosomal dominant and autosomal recessive inheritance. We describe a family with transmission of oculo-auriculo-vertebral spectrum from a mother to her two daughters indicating an autosomal dominant mode of inheritance. Our literature review reveals that patients with autosomal dominant inheritance of oculo-auriculo-vertebral spectrum are more often bilaterally affected than patients with sporadic occurrence of oculo-auriculo-vertebral spectrum. In addition, hearing loss, absent or narrow external auditory canal, anomalies of the mouth and epibulbar dermoids seem to occur less frequently in patients with autosomal dominant oculo-auriculo-vertebral spectrum compared with sporadic oculo-auriculo-vertebral spectrum.

Posterior fossa dermoid cyst in a patient with Goldenhar syndrome

A 7-year-old boy with Goldenhar syndrome was diagnosed to have a posterior cranial fossa dermoid cyst. The presence of such a combination of clinical entities has not been reported earlier. The embryonic dysgenesis causing midline posterior fossa dermoid and other anomalies observed in Goldenhar syndrome occur between the third and fifth week of intrauterine life and are probably interrelated. This report emphasizes the need for a high index of suspicion and the value of cranial imaging in a case with Goldenhar syndrome.

Macrostomia, preauricular tags, and external ophthalmoplegia: a new autosomal dominant syndrome within the oculoauriculovertebral spectrum?

OBJECTIVE

First and second branchial arch involvement during early embryonic development results in a wide spectrum of anomalies that encompass diverse, superimposed, and heterogeneous phenotypes within the so-called oculoauriculovertebral spectrum. Nine members of a Brazilian family presenting typical branchial arch involvement in association with external opthalmoplegia are reported.

CONCLUSION

Macrostomia or abnormal mouth contour, preauricular tags, and uni- or bilateral ptosis were present in association in several patients. To our knowledge, this is the first report on this type of autosomal dominant condition. Clinical and genetic aspects are discussed.

Oculo-auriculo-vertebral spectrum (OAVS): clinical evaluation and severity scoring of 53 patients and proposal for a new classification

Oculo-auriculo-vertebral spectrum (OMIM164210) is a phenotypically and probably also a genetically heterogeneous disorder, characterized by anomalies of the ear (mostly microtia), hemifacial microsomia, and defects of the vertebral column. Associated clinical findings include anomalies of the eye and brain, and developmental delay. We have evaluated the clinical data and photographs of 53 unrelated patients with OAVS, all presenting with either isolated microtia or preauricular tags in association with hemifacial microsomia as minimal diagnostic criteria; five had a positive family history for OAVS. Based on the main clinical findings and unilateral or bilateral involvement, we have developed a new classification system for OAVS, consisting of six subgroups. There is a statistically significant correlation between the subgroup and number of associated clinical findings, and a statistically significant difference regarding prognosis in uni- and bilaterally affected patients, suggesting that this classification is clinically relevant to the categorization of patients with OAVS. The newly developed scoring system (two points for each main clinical finding and one for each associated clinical finding) presented here, also aids prognosis, especially for delay of motor development and brain anomalies, and statistical analysis revealed significant clustering between different clinical findings of OAVS confirming the clinical impression previously published by several authors.

An association between hemifacial microsomia and facial clefting

PURPOSE

Hemifacial microsomia (HFM) is a relatively uncommon malformation, a far second to cleft lip/palate (CL/P). Transverse oral cleft ("macrostomia") is known to be associated with HFM, but there are also reports of concurrent CL/P. We undertook a retrospective study of patients with HFM to document the prevalence of facial clefting. The hypothesis is that the coexistence of facial clefts and HFM suggests a common pathogenic mechanism.

MATERIALS AND METHODS

Records of 198 HFM patients from the database of the Craniofacial Centre at Boston Children's Hospital were reviewed. The age, gender, predominant side of HFM, OMENS classification, and presence, size, and type of cleft (CL/P, transverse oral cleft, or oro-ocular cleft) were documented. We performed chi 2 , t test, and Fishers exact analyses to evaluate the association of facial clefting with HFM.

RESULTS

There were 100 males and 98 females in the HFM study group, with a mean age of 15.3 years (range, 1 to 50 years); 90 were right-sided (45%), 79 were left-sided (40%), and 29 were bilateral (15%). Twenty patients had a CL/P (10%), and of these 15 had unilateral CL/P (UCL/P), equally distributed between right and left sides, and 5 had bilateral CL/P (BCL/P). There were 9 males and 11 females with combined HFM and CL/P. Cleft of the oral commissure (macrostomia) was present in 46 (23.0%) of the HFM patients with a left-to-right-to-bilateral ratio of 5:6:1. There was a significant association between the predominant side of HFM and the side of CL/P ( P < .001) and macrostomia ( P </= .001). We also showed a correlation between the severity of the orbital and mandibular deformities in HFM and the coexisting facial cleft.

CONCLUSIONS

An association implies concurrence, more often than by chance, of 2 or more anomalies and suggests an etiopathologic link. The finding of ipsilateral labial clefts in 10% of HFM patients, and the differing demographic distribution from common labial clefts, suggests an overlapping pathogenesis. Whether the cause is genetic or environmental, we hypothesize that there may be a common pathway leading to a disturbance in neural crest cell migration in HFM patients who also have a facial cleft.

An optic nerve hypoplasia and coloboma in a patient with hemifacial microsomia

Posterior segment anomalies are rare features of the oculoauriculovertebral complex. Our patient had hemifacial microsomia with an optic nerve hypoplasia in one eye and an optic nerve coloboma in the other eye. The optic nerve hypoplasia was ipsilateral to the side with hemifacial microsomia and microtia.

Congenital ameloblastic fibroma in association with oculoauriculovertebral spectrum

Although orodental anomalies have been reported to occur in patients with oculoauriculovertebral spectrum, no previous publications in the English literature have been located that describe an ameloblastic fibroma in a patient with this condition. This report presents a 15-month-old female monozygotic twin with concomitant oculoauriculovertebral spectrum and a congenital ameloblastic fibroma of the mandible. A theory linking the pathogenesis of the two conditions is also raised.