Clinical and cytogenetic features of a Brazilian sample of patients with phenotype of oculo-auriculo-vertebral spectrum: a cross-sectional study

Risk factors and characteristics of the birth of patients with craniofacial microsomia, a case-control study

BACKGROUND

Craniofacial microsomia (CM) is characterized by changes in the first and second branchial arches. It is a clinical condition whose etiology is still uncertain, but studies have shown that genetic, nutritional, and environmental factors can result in disorders of blastogenesis of the branchial arches. This study evaluates gestational aspects, focusing on possible risk factors associated with CM.

METHODS

This is a case-control study conducted with patients monitored at a medical genetics service and compared to a control group of patients without evidence of malformations, born in a mother and child hospital, both located in Porto Alegre, Southern Brazil. Mothers' data were obtained using questionnaires and by reviewing medical records. The sample consisted of 43 patients with CM (cases) and 129 patients without evidence of malformations (controls), paired by sex, totaling three controls for each case. Data analysis was performed using the two-tailed Fisher's exact test, Pearson's chi-square test, and the t-test.

RESULTS

We identified several factors associated with the development of CM, including the use of abortion methods by the mothers of these babies (p = .001), maternal diabetes (p = .009), advanced maternal age (p = .035), and a history of vaginal bleeding (p < .001). Furthermore, these patients exhibited a tendency to be born prematurely (p = .027), with low birth weight (p = .007), and lower Apgar scores (p = .003) when compared to healthy infants. Using a multivariate model, the use of abortion methods (p = .003) and vaginal bleeding (p = .032) remained independently associated with craniofacial microsomia.

CONCLUSIONS

We have identified several risk factors for the development of CM, including a propensity for premature birth, low birth weight, and respiratory difficulties. Additionally, women of advanced maternal age and/or those who used abortion methods and/or have diabetes have a higher risk of giving birth to a baby with CM. This information can be valuable in clinical practice, especially for the prevention of future cases.

Oculo-auriculo-vertebral spectrum: new genes and literature review on a complex disease

Oculo-auriculo-vertebral spectrum (OAVS) or Goldenhar syndrome is due to an abnormal development of first and second branchial arches derivatives during embryogenesis and is characterised by hemifacial microsomia associated with auricular, ocular and vertebral malformations. The clinical and genetic heterogeneity of this spectrum with incomplete penetrance and variable expressivity, render its molecular diagnosis difficult. Only a few recurrent CNVs and genes have been identified as causatives in this complex disorder so far. Prenatal environmental causal factors have also been hypothesised. However, most of the patients remain without aetiology. In this review, we aim at updating clinical diagnostic criteria and describing genetic and non-genetic aetiologies, animal models as well as novel diagnostic tools and surgical management, in order to help and improve clinical care and genetic counselling of these patients and their families.

A child with cat-eye syndrome and oculo-auriculo-vertebral spectrum phenotype: A discussion around molecular cytogenetic findings

Cat eye syndrome (CES) is a rare chromosomal disorder that may be evident at birth. A small supernumerary chromosome is present, frequently has 2 centromeres, is bisatellited, and represents an inv dup(22)(q11) in those affected. It's known that the 22q11 region is associated with disorders involving higher and lower gene dosages. Conditions such as CES, 22q11 microduplication syndrome (Dup22q11) and oculoauriculovertebral spectrum phenotype (OAVS) may share genes belonging to this same region, which is known to have a predisposition to chromosomal rearrangements. The conditions, besides being related to chromosome 22, also share similar phenotypes. Here we have added a molecular evaluation update and results found of the first patient described with CES and OAVS phenotype, trying to explain the potential mechanism involved in the occurrence of this association.

Craniofacial microsomia: Reflections on diagnosis and severity assessment based on a series of cases

This study aims to discuss diagnostic criteria and severity assessment for craniofacial microsomia (CFM). A series of 61 patients with diverse CFM phenotypes had their clinical data collected by experienced dysmorphologists using a single protocol. Genetic abnormalities were searched through karyotype and chromosomal microarray analysis. Sex ratio, prenatal risk factors, and recurrence rate corroborated the literature. Despite the wide variability of clinical findings, ear disruption was universal. Eight patients were assigned as syndromic, four of whom had demonstrable genetic alterations. The majority of patients (67.2%) fulfilled four known diagnostic criteria, while 9.8% fulfilled one of them. Data strengthened disruptions of the ear and deafness as a semiotically valuable sign in CFM. Facial impairment should consider asymmetry as a mild expression of microsomia. Spinal and cardiac anomalies, microcephaly, and developmental delay were prevalent among extra craniofacial features and should be screened before planning treatment and follow up. The severity index was able to recognize the less and the most affected patients. However, it was not useful to support therapeutic decisions and prognosis in the clinical scenario due to syndromic and non-syndromic phenotypes overlapping. These issues make contemporary the debate on diagnostic methods and disease severity assessment for CFM. They also impact care and etiopathogenetic studies.

OCULO-AURICULO-VERTEBRAL SPECTRUM ASSOCIATED WITH ABERRANT SUBCLAVIAN ARTERY IN AN INFANT WITH RECURRENT RESPIRATORY DISTRESS

Objective:

To describe an infant with craniofacial microsomia and recurrent respiratory distress associated with aberrant right subclavian artery in order to review its most frequent congenital anomalies and alert the pediatrician to its rarer and more severe complications.

Case description:

This case report involves an 18-month-old male infant, only son of non-consanguineous parents. At birth, the child presented craniofacial dysmorphisms (facial asymmetry, maxillary and mandibular hypoplasia, macrostomia, grade 3 microtia, and accessory preauricular tag) restricted to the right side of the face. Additional tests showed asymmetric hypoplasia of facial structures and thoracic hemivertebrae. No cytogenetic or cytogenomic abnormalities were identified. The patient progressed to several episodes of respiratory distress, stridor, and nausea, even after undergoing gastrostomy and tracheostomy in the neonatal period. Investigation guided by respiratory symptoms identified compression of the esophagus and trachea by an aberrant right subclavian artery. After surgical correction of this anomaly, the infant has not presented respiratory symptoms and remains under multidisciplinary follow-up, seeking rehabilitation.

Comments:

Craniofacial microsomia presents a wide phenotypic variability compared to both craniofacial and extracraniofacial malformations. The latter, similarly to the aberrant right subclavian artery, is rarer and associated with morbidity and mortality. The main contribution of this case report was the identification of a rare anomaly, integrating a set of malformations of a relatively common condition, responsible for a very frequent complaint in pediatric care.

A recurrent missense variant in EYA3 gene is associated with oculo-auriculo-vertebral spectrum

Goldenhar syndrome or oculo-auriculo-vertebral spectrum (OAVS) is a complex developmental disorder characterized by asymmetric ear anomalies, hemifacial microsomia, ocular and vertebral defects. We aimed at identifying and characterizing a new gene associated with OAVS. Two affected brothers with OAVS were analyzed by exome sequencing that revealed a missense variant (p.(Asn358Ser)) in the EYA3 gene. EYA3 screening was then performed in 122 OAVS patients that identified the same variant in one individual from an unrelated family. Segregation assessment in both families showed incomplete penetrance and variable expressivity. We investigated this variant in cellular models to determine its pathogenicity and demonstrated an increased half-life of the mutated protein without impact on its ability to dephosphorylate H2AFX following DNA repair pathway induction. Proteomics performed on this cellular model revealed four significantly predicted upstream regulators which are PPARGC1B, YAP1, NFE2L2 and MYC. Moreover, eya3 knocked-down zebrafish embryos developed specific craniofacial abnormalities corroborating previous animal models and supporting its involvement in the OAVS. Additionally, EYA3 gene expression was deregulated in vitro by retinoic acid exposure. EYA3 is the second recurrent gene identified to be associated with OAVS. Moreover, based on protein interactions and related diseases, we suggest the DNA repair as a key molecular pathway involved in craniofacial development.

Microarray-Based Comparative Genomic Hybridization, Multiplex Ligation-Dependent Probe Amplification, and High-Resolution Karyotype for Differential Diagnosis Oculoauriculovertebral Spectrum: A Systematic Review

Oculoauriculovertebral spectrum (OAVS) is a rare class of heterogenous congenital craniofacial malformation conditions of unknown etiology. Although classic OAVS has been described as hemifacial microsomia with facial asymmetry and microtia, there is no consensus regarding clinical criteria for diagnosis or genetic cause. This systematic review aims to assess the applicability of high-resolution (HR) karyotype, fluorescence in situ hybridization, multiplex ligation-dependent probe amplification (MLPA), and microarray-based comparative genomic hybridization (array-CGH) for differential diagnosis of OAVS. A search was performed in PubMed and Web of Science using all entry terms to the following descriptors: Goldenhar's syndrome, cytogenetic analysis, hybridization in situ, fluorescent, comparative genomic hybridization, multiplex polymerase chain reaction, whole genome sequencing, and karyotype analysis methods. After screening, 25 articles met eligibility. Of the included studies, 59 individuals had a genetic alteration identified. Array-CGH, MLPA, and HR karyotype appear to be viable approaches for molecular diagnosis in OAVS. Heterogeneity is a hallmark of OAVS. Establishing an enhanced framework for diagnosis would inform clinical decision making, and better resource utilization could improve health care facility efficiency and economy.

Oculo-Auriculo-Vertebral Dysplasia With Craniocervical Instability and Occult Tethered Cord Syndrome. An Addition to the Spectrum? First Case Report and Review of the Literature

Oculo-auriculo-vertebral spectrum (OAVS) is an uncommon congenital disorder of abnormal development of the first and second pharyngeal arches. This spectrum is characterized by craniofacial microsomia, epibulbar dermoids, ear abnormalities, renal and cardiac defects, and a wide range of vertebral segmentation and formation disorders. Frequently, the cervicothoracic spine is involved. Only recently, the morbidity attributed to the spinal abnormalities has gained attention. Strategy and timing of spine surgery has become increasingly important in patients with OAVS. Here, we report a case of OAVS with characteristic vertebral cervical and thoracic involvement and its sequelae requiring multiple spinal procedures, further complexed by an unprecedented occult tethered cord syndrome, which was successfully treated by surgical detethering. In this context, the recent literature on spinal anomalies is reviewed.

Distal deletion at 22q11.2 as differential diagnosis in Craniofacial Microsomia: Case report and literature review

Craniofacial Microsomia (CFM) also known as Oculo-auriculo-vertebral Spectrum (OAVS) or Goldenhar Syndrome, presents wide phenotypic and etiological heterogeneity. It affects mainly the structures originated from the first and second pharyngeal arches. In addition, other major anomalies may also be found, including congenital heart diseases. In this study, we report a patient with distal deletion in the 22q11.2 region and a phenotype which resembles CFM. The proband is a girl, who presented bilateral preauricular tags, left auditory canal stenosis, malar hypoplasia, cleft lip and palate, mild asymmetry of soft tissue in face, congenital heart disease, intestinal atresia, annular pancreas and hydronephrosis. The genomic imbalances investigation by Multiplex Ligation-dependent Probe Amplification (MLPA) and Chromosomal Microarray Analysis (CMA) revealed a distal deletion of 1,048 kb at 22q11.2 encompassing the region from Low Copy Repeats (LCRs) D to E. We did review of the literature and genotype-phenotype correlation. This is the sixth case of distal 22q11.2 deletion resembling CFM and the second encompassing the region between LCRs D to E. All cases share some phenotypic signs, such as preauricular tags, facial asymmetry, cleft lip and palate, and congenital heart diseases. Candidate genes in this region have been studied by having an important role in pharyngeal arches developmental and in congenital heart diseases, such as HIC2, YPEL1and MAPK1/ERK2. This case corroborates the phenotypic similarity between 22q11.2 distal deletion and CFM/OAVS. It also contributes to genotype-phenotype correlation and reinforces that candidate genes for CFM, in the 22q11.2 region, might be located between LCRs D and E.