[Clinical case analysis and literature review of mandibulofacial dysostosis with microcephaly syndrome]

Objective:To explore the clinical diagnosis, otological treatment and molecular etiology in a rare syndromic hearing loss case characterized by mandibulofacial dysostosis with microcephaly（MFDM）. Methods: The proband underwent detailed history collection, systematic physical examination and phenotypic analysis, as well as audiological examination, chest X-ray, temporal bone CT and brain MRI and other imaging examinations. The blood DNA of the proband and his parents was extracted and tested by the whole exom sequencing. The EFTUD2-related-MFDM literatures published by the end of 2020 were searched and sifted in PubMed and CNKI databases,the clinical characteristics of MFDM were summarized. Results:In this study, the patient presented with hypoplasia of auricle, micrognathia, microcephaly, developmental retardation, severe sensorineural hearing loss in both ears, and developmental malformation of middle and inner ear. Genetic analysis revealed a de novo deletion c.623_624delAT in EFTUD2 gene. According to the clinical features and genetic test results, the patient was diagnosed as MFDM. In order to solve the problem of hearing loss, the patient was further performed bilateral cochlear implantation, and part of the electrodes responded well during and after operation. Conclusion:This is the first domestic reported case of MFDM caused by EFTUD2 gene mutation. The key problem of cochlear implantation for this kind of patient is to avoid damaging the malformed facial nerve during the operation.The effect of speech rehabilitation after cochlear implant operation is related to many factors such as intelligence development of the patients.