Hearing Intervention For Patients With Bilateral Microtia And The Screening And Functional Study Of Pathogenic Genes In Families Of Ear-mandibular Dysplasia Syndrome

Part One Clinical Research Hearing improvement with softband and implanted bone-anchored hearing devices and modified implantation surgery in patients with bilateral microtia-atresiaObjecives We aimed to evaluate auditory development and hearing improvement in patients with bilateral microtia-atresia using softband and implanted bone-anchored hearing devices and to modify the implantation surgery.Methods The subjects were divided into two groups:the softband group(40 infants,3 months to 2 years old,Ponto softband)and the implanted group(6 patients,6 to 28 years old,Ponto).The Infant-Toddler Meaning Auditory Integration Scale was used conducted to evaluate auditory development at baseline and after 3,6,12,and 24 months,and visual reinforcement audiometry was used to assess the auditory threshold in the softband group.In the implanted group,bone-anchored hearing devices were implanted combined with the auricular reconstruction surgery,and high-resolution CT was used to assess the deformity preoperatively.Auditory threshold and speech discrimination scores of the patients with implants were measured under the unaided,softband,and implanted conditions.Results Total Infant-Toddler Meaning Auditory Integration Scale scores in the softband group improved significantly and approached normal levels.The average visual reinforcement audiometry values under the unaided and softband conditions were 76.75±6.05 dB SPL and 32.25±6.20 dB SPL(P<0.01),respectively.In the implanted group,the auditory thresholds under the unaided,softband,and implanted conditions were 59.17±3.76 dB SPL,32.5±2.74 dB SPL,and 17.5±5.24 dB SPL(P<0.01),respectively.The respective speech discrimination scores were 23.33±14.72%,77.17±6.46%,and 96.50±2.66%(P<0.01).Conclusions Both softband and implanted bone-anchored hearing devices had curative effects on auditory development and hearing in patients with bilateral microtia-atresia.Using softband bone-anchored hearing devices before auricle reconstruction and combining bone-anchored hearing device implantation with auricular reconstruction surgery is the optimal clinical choice for these patients,and results in more significant hearing improvement and minimal surgical and anesthetic injury.Part Two Basic Research Mutation in vwal is a Cause of Otomandibular DysostosisObjectives We aimed to identify the causative genes of Hemifacial Microsomia,understanding the relationship between the candidate genes and craniofacial development through the animal model of zebrafish.Methods We performed the whole exome sequencing(WES)of the members of Hemifacial Microsomia pedigree,looking for the de novo mutations.Morpholino and CRISPR/Cas9 techniques were used to edit vwal in the zebrafish.The Alcian Blue cartilage staining was used to observe the morphologies of pharyngeal cartilages.The Whole-mount in situ hybridization was used to detect the spatial-temporal profiles of vwal and the developmental process of cranial neural crest and endodermal-pounch.The immunofluorescence was used to investigate the proliferation and apoptosis of cranial neural crest cells.Results By WES,we identified a nonsynonymous mutation in VWA1.The knock down and knock out of vwal by morpholino and CRISPR/Cas9 both resulted in the deformities of pharyngeal cartilages.vwal was differentially expressed in the mandibular of zebrafish.The knockdown of vwal did not influence the specification of cranial neural crest and endodermal-pouch.vwal was essential in the proliferation of cranial neural crest.Conclusions vwal is the causative gene of Hemifacial Microsomia.vwal is required for the proliferation of cranial neural crest and the pharyngeal cartilage formation.