RESUMO
Goldenhar syndrome, a rare craniofacial malformation, is characterized by developmental anomalies in the first and second pharyngeal arches. Its etiology is considered to be heterogenous, including both genetic and environmental factors that remain largely unknown. To further elucidate the genetic cause in a five-generation Goldenhar syndrome pedigree and exploit the whole-exome sequencing (WES) data of this pedigree, we generated collapsed haplotype pattern markers based on WES and employed rare variant nonparametric linkage analysis. FBLN2 was identified as a candidate gene via analysis of WES data across the significant linkage region. A fbln2 knockout zebrafish line was established by CRISPR/Cas9 to examine the gene's role in craniofacial cartilage development. fbln2 was expressed specifically in the mandible during the zebrafish early development, while fbln2 knockout zebrafish exhibited craniofacial malformations with abnormal chondrocyte morphologies. Functional studies revealed that fbln2 knockout caused abnormal chondrogenic differentiation, apoptosis, and proliferation of cranial neural crest cells (CNCCs), and downregulated the bone morphogenic protein (BMP) signaling pathway in the zebrafish model. This study demonstrates the role of FBLN2 in CNCC development and BMP pathway regulation, and highlights FBLN2 as a candidate gene for Goldenhar syndrome, which may have implications for the selection of potential screening targets and the development of treatments for conditions like microtia-atresia.
Assuntos
Síndrome de Goldenhar , Crista Neural , Linhagem , Peixe-Zebra , Animais , Peixe-Zebra/embriologia , Peixe-Zebra/genética , Crista Neural/metabolismo , Síndrome de Goldenhar/genética , Síndrome de Goldenhar/metabolismo , Síndrome de Goldenhar/patologia , Humanos , Feminino , Masculino , Diferenciação Celular/genética , Sequenciamento do Exoma , Condrogênese/genética , Transdução de Sinais/genética , Proteínas de Peixe-Zebra/genética , Proteínas de Peixe-Zebra/metabolismo , Proteínas Morfogenéticas Ósseas/metabolismo , Proteínas Morfogenéticas Ósseas/genéticaRESUMO
Hemifacial microsomia (HFM) is a rare congenital genetic syndrome primarily affecting the first and second pharyngeal arches, leading to defects in the mandible, external ear, and middle ear. The pathogenic genes remain largely unidentified. Whole-exome sequencing (WES) was conducted on 12 HFM probands and their unaffected biological parents. Predictive structural analysis of the target gene was conducted using PSIPRED (v3.3) and SWISS-MODEL, while STRING facilitated protein-to-protein interaction predictions. CRISPR/Cas9 was applied for gene knockout in zebrafish. In situ hybridization (ISH) was employed to examine the spatiotemporal expression of the target gene and neural crest cell (NCC) markers. Immunofluorescence with PH3 and TUNEL assays were used to assess cell proliferation and apoptosis. RNA sequencing was performed on mutant and control embryos, with rescue experiments involving target mRNA injections and specific gene knockouts. CDC27 was identified as a novel candidate gene for HFM, with four nonsynonymous de novo variants detected in three unrelated probands. Structural predictions indicated significant alterations in the secondary and tertiary structures of CDC27. cdc27 knockout in zebrafish resulted in craniofacial malformation, spine deformity, and cardiac edema, mirroring typical HFM phenotypes. Abnormalities in somatic cell apoptosis, reduced NCC proliferation in pharyngeal arches, and chondrocyte differentiation issues were observed in cdc27-/- mutants. cdc27 mRNA injections and cdkn1a or tp53 knockout significantly rescued pharyngeal arch cartilage dysplasia, while sox9a mRNA administration partially restored the defective phenotypes. Our findings suggest a functional link between CDC27 and HFM, primarily through the inhibition of CNCC proliferation and disruption of pharyngeal chondrocyte differentiation.
Assuntos
Síndrome de Goldenhar , Peixe-Zebra , Animais , Peixe-Zebra/genética , Humanos , Masculino , Feminino , Síndrome de Goldenhar/genética , Síndrome de Goldenhar/patologia , Apoptose/genética , Crista Neural/metabolismo , Sequenciamento do Exoma , Proliferação de Células/genética , Fenótipo , Mutação , Técnicas de Inativação de GenesRESUMO
Craniofacial microsomia (CFM), also known as the oculo-auriculo-vertebral spectrum, is a congenital disorder characterized by hypoplasia of the mandible and external ear due to tissue malformations originating from the first and second branchial arches. However, distinguishing it from other syndromes of branchial arch abnormalities is difficult, and causal variants remain unidentified in many cases. In this report, we performed an exome sequencing analysis of a Brazilian family with CFM. The proband was a 12-month-old boy with clinical findings consistent with the diagnostic criteria for CFM, including unilateral mandibular hypoplasia, microtia, and external auditory canal abnormalities. A heterozygous de novo nonsense variant (c.713C>G, p.S238*) in PUF60 was identified, which was predicted to be pathogenic in silico. PUF60 has been reported as a causal gene in Verheij syndrome, but not in CFM. Although the boy showed craniofacial abnormalities and developmental delay that overlapped with Verheij syndrome, the facial asymmetry with unilateral hypoplasia of the mandible observed in this case did not match the previously reported phenotypes of PUF60 variants. Our findings expand the phenotypic range of PUF60 variants that cover CFM and Verheij syndrome.
Assuntos
Síndrome de Goldenhar , Fenótipo , Humanos , Masculino , Síndrome de Goldenhar/genética , Síndrome de Goldenhar/patologia , Síndrome de Goldenhar/diagnóstico , Lactente , Fatores de Processamento de RNA/genética , Proteínas Repressoras/genética , Sequenciamento do Exoma , Mandíbula/anormalidades , Mandíbula/patologia , Linhagem , Códon sem Sentido/genéticaRESUMO
Craniofacial microsomia (CFM) primarily includes specific head and neck anomalies that co-occur more frequently than expected. The anomalies are usually asymmetric and affect craniofacial features; however, there are frequently additional anomalies of variable severity. Published prenatal findings for CFM are limited. This study contributes 11 cases with CFM and their anomalies identified prenatally. Cases born between January 1, 1997 and December 31, 2019 with CFM were abstracted from the Alberta Congenital Anomalies Surveillance System, which is a population-based program ascertaining congenital anomalies for livebirths, stillbirths, and termination of pregnancies for fetal anomalies. There were 11 cases ascertained with prenatal findings including facial anomalies: one each with left cleft lip, right microtia, and bilateral microphthalmia. Two cases had vertebral anomalies. In addition, anomalies of the kidneys, brain, heart, and radial ray were identified. Six (55%) had a single umbilical artery, five (45%) were small for gestational age, and three (27%) were from a twin pregnancy that were discordant for anomalies. Four (36%) overlapped another proposed recurrent constellations of embryonic malformation condition. This study describes prenatal findings for 11 cases with CFM. Comparable to prior published cases, there were recurring anomalies on prenatal imaging, including anomalies of the brain, eye, heart, kidneys, and radial ray, which may aid in the prenatal diagnosis of CFM.
Assuntos
Síndrome de Goldenhar , Humanos , Feminino , Gravidez , Masculino , Síndrome de Goldenhar/genética , Síndrome de Goldenhar/epidemiologia , Síndrome de Goldenhar/diagnóstico , Síndrome de Goldenhar/patologia , Alberta/epidemiologia , Diagnóstico Pré-Natal , Adulto , Recém-Nascido , Fenda Labial/epidemiologia , Fenda Labial/patologia , Fenda Labial/genética , Fenda Labial/diagnóstico , Fenda Labial/diagnóstico por imagem , Ultrassonografia Pré-Natal , Anormalidades Múltiplas/epidemiologia , Anormalidades Múltiplas/genética , Anormalidades Múltiplas/patologia , Anormalidades Múltiplas/diagnósticoRESUMO
BACKGROUND: To report a case of a 4-year-old patient with Goldenhar syndrome. CASE PRESENTATION: The author presents a rare case report involving a 4-year-old boy with multiple malformations. A comprehensive examination showed that the patient primarily had a limbal dermoid. He also has bilateral microtia and ear canal deformities. The skull CT scan and spine X-ray showed Maxillofacial Abnormalities and scoliosis. Whole Exome Sequencing revealed potential gene variations related to microtia. Although certain circumstances prevented us from initiating follow-up treatment for the patient, we have provided a detailed account of the diagnostic methodologies used for this condition. CONCLUSIONS: Goldenhar syndrome is a congenital condition, predominantly presenting as sporadic cases. Its diagnosis and management typically necessitate the involvement of multiple disciplines, including otolaryngology and craniofacial surgery. The syndrome encompasses a variety of craniofacial features, which can facilitate early diagnosis and guide subsequent therapeutic interventions.
Assuntos
Anormalidades Múltiplas , Microtia Congênita , Neoplasias Oculares , Síndrome de Goldenhar , Masculino , Humanos , Pré-Escolar , Síndrome de Goldenhar/diagnóstico , Síndrome de Goldenhar/genética , Microtia Congênita/diagnóstico , Anormalidades Múltiplas/diagnóstico , Tomografia Computadorizada por Raios XRESUMO
A boy in his early childhood was brought for a comprehensive eye examination as advised by a paediatrician. The child had plagiocephaly, absent left ear (anotia), facial asymmetry, deviation of mouth to the left side, receding chin and teeth, scoliosis and a Mongolian spot on the lower back. There was also absence of seventh and eighth cranial nerves on the left side on MRI of the brain. Echocardiography showed a small ventricular septal defect and a single umbilical artery. Gross motor milestones were delayed and on ocular examination, the child showed right eye preference and retinochoroidal coloboma in the left eye. The child was managed with a multidisciplinary approach involving the paediatrician, ENT specialist, ophthalmologist, clinical geneticist and rehabilitative services. The child was managed conservatively with spectacles and occlusion therapy of the right eye, and genetic counselling was given along with a left hearing aid and rehabilitation.
Assuntos
Síndrome CHARGE , Síndrome de Goldenhar , Escoliose , Masculino , Criança , Humanos , Pré-Escolar , Síndrome de Goldenhar/diagnóstico , Síndrome de Goldenhar/terapia , Síndrome de Goldenhar/genética , Orelha , Assimetria FacialRESUMO
OBJECTIVES: Hemifacial microsomia (HFM) is a common birth defect involving the first and second branchial arch derivatives. Although several chromosomal abnormalities and causal gene variants have been identified, genetic etiologies in a majority of cases with HFM remain unknown. This study aimed to identify genetic mutations in affected individuals with HFM. METHODS: Whole-exome sequencing and bioinformatics analysis were performed for 16 affected individuals and their family members. Sanger sequencing was applied for confirmation of selected mutations. Zebrafish embryos were used for in situ hybridization of candidate gene, microinjection with antisense morpholino, and cartilage staining. RESULTS: A homozygous missense mutation (c.484G > A; p.V162I) in the FRK gene was identified in an 18-year-old girl with HFM and dental abnormalities. Heterozygous mutation of this mutation was identified in her parents, who are first cousins in a consanguineous family. FRK is highly expressed in the Meckel's cartilage during embryonic development in mouse and zebrafish. Knockdown of frk in zebrafish showed a lower length and width ratio of Meckel's cartilage, abnormal mandibular jaw joint, and disorganized ceratobranchial cartilage and bone. CONCLUSIONS: We identified a recessive variant in the FRK gene as a novel candidate gene for a patient with HFM and mandibular hypoplasia and revealed its effects on craniofacial and embryonic development in zebrafish.
Assuntos
Síndrome de Goldenhar , Humanos , Feminino , Camundongos , Animais , Adolescente , Síndrome de Goldenhar/genética , Peixe-Zebra/genética , Mandíbula/anormalidades , Articulação Temporomandibular , Cartilagem , Proteínas de Neoplasias , Proteínas Tirosina QuinasesRESUMO
PURPOSE: Craniofacial microsomia (CFM) represents a spectrum of craniofacial malformations, ranging from isolated microtia with or without aural atresia to underdevelopment of the mandible, maxilla, orbit, facial soft tissue, and/or facial nerve. The genetic causes of CFM remain largely unknown. METHODS: We performed genome sequencing and linkage analysis in patients and families with microtia and CFM of unknown genetic etiology. The functional consequences of damaging missense variants were evaluated through expression of wild-type and mutant proteins in vitro. RESULTS: We studied a 5-generation kindred with microtia, identifying a missense variant in FOXI3 (p.Arg236Trp) as the cause of disease (logarithm of the odds = 3.33). We subsequently identified 6 individuals from 3 additional kindreds with microtia-CFM spectrum phenotypes harboring damaging variants in FOXI3, a regulator of ectodermal and neural crest development. Missense variants in the nuclear localization sequence were identified in cases with isolated microtia with aural atresia and found to affect subcellular localization of FOXI3. Loss of function variants were found in patients with microtia and mandibular hypoplasia (CFM), suggesting dosage sensitivity of FOXI3. CONCLUSION: Damaging variants in FOXI3 are the second most frequent genetic cause of CFM, causing 1% of all cases, including 13% of familial cases in our cohort.
Assuntos
Microtia Congênita , Síndrome de Goldenhar , Micrognatismo , Humanos , Síndrome de Goldenhar/genética , Microtia Congênita/genética , Orelha/anormalidades , FaceRESUMO
BACKGROUND: Oculo-auriculo-vertebral spectrum (OAVS) is the second most common cause of head and neck malformations in children after orofacial clefts. OAVS is clinically heterogeneous and characterised by a broad range of clinical features including ear anomalies with or without hearing loss, hemifacial microsomia, orofacial clefts, ocular defects and vertebral abnormalities. Various genetic causes were associated with OAVS and copy number variations represent a recurrent cause of OAVS, but the responsible gene often remains elusive. METHODS: We described an international cohort of 17 patients, including 10 probands and 7 affected relatives, presenting with OAVS and carrying a 14q22.3 microduplication detected using chromosomal microarray analysis. For each patient, clinical data were collected using a detailed questionnaire addressed to the referring clinicians. We subsequently studied the effects of OTX2 overexpression in a zebrafish model. RESULTS: We defined a 272 kb minimal common region that only overlaps with the OTX2 gene. Head and face defects with a predominance of ear malformations were present in 100% of patients. The variability in expressivity was significant, ranging from simple chondromas to severe microtia, even between intrafamilial cases. Heterologous overexpression of OTX2 in zebrafish embryos showed significant effects on early development with alterations in craniofacial development. CONCLUSIONS: Our results indicate that proper OTX2 dosage seems to be critical for the normal development of the first and second branchial arches. Overall, we demonstrated that OTX2 genomic duplications are a recurrent cause of OAVS marked by auricular malformations of variable severity.
Assuntos
Fenda Labial , Fissura Palatina , Síndrome de Goldenhar , Humanos , Animais , Síndrome de Goldenhar/genética , Peixe-Zebra/genética , Variações do Número de Cópias de DNA/genética , Fatores de Transcrição Otx/genéticaRESUMO
Oculo-auriculo-vertebral syndrome (OAVS) is a clinically heterogeneous disorder, with both genetic and environmental contributors. Multiple genes have been associated with OAVS and common molecular pathways, such as retinoic acid and the PAX-SIX-EYA-DACH (PSED) network, are being implicated in the disease pathophysiology. Biallelic homozygous nonsense or hypomorphic missense mutations in PAX1 cause otofaciocervical syndrome type 2 (OTFCS2), a similar but more severe multi-system disorder that can be accompanied by severe combined immunodeficiency due to thymic aplasia. Here we have identified a multi-generational family with mild features of OAVS segregating a heterozygous frameshift in PAX1. The four base duplication is expected to result in nonsense-mediated decay, and therefore cause a null allele. While there was full penetrance of the variant, expressivity of facial and ear features were variable. Our findings indicate there can be monoallelic and biallelic disorders associated with PAX1, and further implicate the PSED network in OAVS.
Assuntos
Síndrome de Goldenhar , Fatores de Transcrição Box Pareados , Imunodeficiência Combinada Severa , Síndrome de Goldenhar/genética , Homozigoto , Humanos , Mutação de Sentido Incorreto , Fatores de Transcrição Box Pareados/genética , TretinoínaRESUMO
A diagnosis of oculo-auriculo-vertebral spectrum (OAVS) is established when microtia is present in association with hemifacial hypoplasia (HH) and/or ocular, vertebral, and/or renal malformations. There is no consensus on which imaging studies should be used to rule out variable expressivity and distinguish "sporadic" from "familial" patients. This observational and descriptive study was performed in a Mexican population of 51 patients (32 males, 19 females, 0-18 years old) with microtia/OAVS, and their available parents. A clinical history, genealogy, and physical examination were obtained from all included patients, as were a computed tomography (CT) scan of the ear, audiological evaluation, orthopantomography, complete spine radiography, and renal ultrasound. The same approach was completed in their available parents (51 mothers and 40 fathers), excluding the CT scan and audiological evaluation. By genealogy, 53% of patients were classified as "sporadic"; of the "familial" patients, at least 79.1% had suggestion of a multifactorial inheritance. In the available parents, orthopantomography, complete spine X-ray, and renal ultrasound identified the following OAVS-related manifestations: HH (16.2%, n = 14/86), vertebral alterations (10.9%, n = 10/91), and renal anomalies (2.2%, n = 2/90). Our evaluation of the parents allowed three patients to be reclassified from "sporadic" to "familial" (5.8%, n = 3/51). Our proposed clinical and imaging approach allowed the identification of variable expressivity that more clearly distinguished between "sporadic" and "familial" OAVS patients, which is of utmost importance in providing proper genetic counseling to these families.
Assuntos
Microtia Congênita , Síndrome de Goldenhar , Adolescente , Criança , Pré-Escolar , Feminino , Síndrome de Goldenhar/diagnóstico por imagem , Síndrome de Goldenhar/genética , Humanos , Lactente , Recém-Nascido , Masculino , México , Coluna Vertebral/diagnóstico por imagem , Tomografia Computadorizada por Raios XRESUMO
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.
Assuntos
Síndrome de Goldenhar , Animais , Região Branquial , Variações do Número de Cópias de DNA , Síndrome de Goldenhar/diagnóstico , Síndrome de Goldenhar/genética , HumanosRESUMO
The etiology of oculo-auriculo-vertebral spectrum (OAVS) is not well established. About half of patients show a positive family history. The etiology of familiar cases is unclear but appears genetically heterogeneous. This motivated us to report a case of OAVS with microtia, ptosis, facial microsomy, and fusion of vertebral bodies associated with a novel genetic etiology, including a deletion at 1p36.12-13. This case report expands on the genetic etiology of OAVS. Furthermore, it also expands the clinical manifestations of patients with interstitial deletions of the de 1p36.12-13 region.
Assuntos
Síndrome de Goldenhar , Humanos , Síndrome de Goldenhar/genéticaRESUMO
OBJECTIVE: Oculoauriculovertebral spectrum (OAVS) is a genetically and clinically heterogeneous disorder that occurs due to a developmental field defect of the first and second pharyngeal arches. Even though recent whole exome sequencing studies (WES) have led to identification of several genes associated with this spectrum in a subset of individuals, complete pathogenesis of OAVS remains unsolved. In this study, molecular genetic etiology of OAVS was systematically investigated. DESIGN/SETTING/PATIENTS: A cohort of 23 Turkish patients with OAVS, referred to Hacettepe University Hospital, Department of Pediatric Genetics from 2008 to 2018, was included in this study. Minimal diagnostic criteria for OAVS were considered as unilateral microtia or hemifacial microsomia with preauricular skin tag. The cohort was clinically reevaluated for craniofacial and extracranial findings. Molecular etiology was investigated using candidate gene sequencing following copy number variant (CNV) analysis. WES was also performed for 2 of the selected patients. RESULTS: Patients in the study cohort presented similar demographic and phenotypic characteristics to previously described patients in the literature except for a higher frequency of bilaterality, cardiac findings, and intellectual disability/developmental delay. CNV analysis revealed a possible genetic etiology for 3 patients (13%). Additional WES in 1 of the 2 patients uncovered a novel heterozygous nonsense variant in Elongation factor Tu GTP-binding domain-containing 2 (EFTUD2) causing mandibulofacial dysostosis with microcephaly (MFDM), which clinically overlaps with OAVS. CONCLUSION: Detailed clinical evaluation for any patient with OAVS is recommended due to a high rate of accompanying systemic findings. We further expand the existing genetic heterogeneity of OAVS by identifying several CNVs and a phenotypically overlapping disorder, MFDM.
Assuntos
Síndrome de Goldenhar , Disostose Mandibulofacial , Microcefalia , Criança , Estudos de Coortes , Deficiências do Desenvolvimento/genética , Síndrome de Goldenhar/genética , Humanos , Disostose Mandibulofacial/genética , Microcefalia/genética , Fatores de Alongamento de Peptídeos/genética , Ribonucleoproteína Nuclear Pequena U5/genéticaRESUMO
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.
Assuntos
Transtornos Cromossômicos/genética , Duplicação Cromossômica , Anormalidades do Olho/genética , Síndrome de Goldenhar/genética , Aneuploidia , Criança , Transtornos Cromossômicos/patologia , Cromossomos Humanos Par 22/genética , Hibridização Genômica Comparativa , Anormalidades do Olho/patologia , Feminino , Dosagem de Genes , Síndrome de Goldenhar/patologia , HumanosRESUMO
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.
Assuntos
Síndrome de Goldenhar/genética , Haploinsuficiência , Fatores de Processamento de RNA/genética , Adolescente , Adulto , Animais , Criança , Exoma/genética , Feminino , Estudos de Associação Genética , Síndrome de Goldenhar/patologia , Humanos , Lactente , Masculino , Mutação , Crista Neural/crescimento & desenvolvimento , Crista Neural/patologia , Linhagem , Spliceossomos/genética , Xenopus laevisRESUMO
In this report, we describe an unusual case of progressive hemifacial atrophy or Parry-Romberg syndrome in a 10-year-old girl with progressive hemifacial microsomia and limb anomalies who had brain magnetic resonance imaging (MRI) findings of white matter hyper-intensities. Patients typically present with neurological manifestations such as epilepsy, facial pain, and migraines and ophthalmological symptoms in conjunction with white matter lesions. The patient demonstrated normal cognition and psychomotor development despite the presence of white matter lesions in her frontal lobe that is commonly associated with neurological symptoms. This report brings attention to the complicated relationship between facial, limb and brain imaging findings in Parry-Romberg syndrome and differentiates it from hemifacial microsomia syndrome.
Assuntos
Encéfalo/patologia , Hemiatrofia Facial/patologia , Síndrome de Goldenhar/patologia , Deformidades Congênitas dos Membros/patologia , Encéfalo/diagnóstico por imagem , Criança , Hemiatrofia Facial/genética , Feminino , Síndrome de Goldenhar/genética , Humanos , Deformidades Congênitas dos Membros/genética , FenótipoRESUMO
Oculo-auriculo-vertebral spectrum (OAVS) is a developmental disorder of craniofacial morphogenesis. Its etiology is unclear, but assumed to be complex and heterogeneous, with contribution of both genetic and environmental factors. We assessed the occurrence of copy number variants (CNVs) in a cohort of 19 unrelated OAVS individuals with congenital heart defect. Chromosomal microarray analysis identified pathogenic CNVs in 2/19 (10.5%) individuals, and CNVs classified as variants of uncertain significance in 7/19 (36.9%) individuals. Remarkably, two subjects had small intragenic CNVs involving DACH1 and DACH2, two paralogs coding for key components of the PAX-SIX-EYA-DACH network, a transcriptional regulatory pathway controlling developmental processes relevant to OAVS and causally associated with syndromes characterized by craniofacial involvement. Moreover, a third patient showed a large duplication encompassing DMBX1/OTX3, encoding a transcriptional repressor of OTX2, another transcription factor functionally connected to the DACH-EYA-PAX network. Among the other relevant CNVs, a deletion encompassing HSD17B6, a gene connected with the retinoic acid signaling pathway, whose dysregulation has been implicated in craniofacial malformations, was also identified. Our findings suggest that CNVs affecting gene dosage likely contribute to the genetic heterogeneity of OAVS, and implicate the PAX-SIX-EYA-DACH network as novel pathway involved in the etiology of this developmental trait.
Assuntos
Variações do Número de Cópias de DNA , Síndrome de Goldenhar/genética , Cardiopatias Congênitas/genética , Adolescente , Adulto , Criança , Pré-Escolar , Estudos de Coortes , Feminino , Síndrome de Goldenhar/fisiopatologia , Humanos , Lactente , Recém-Nascido , Masculino , Análise em Microsséries , Polimorfismo de Nucleotídeo Único , Adulto JovemRESUMO
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.