EP07.14: Agnathia‐Otocephaly Complex: a case study and literature review

Agnathia is a rare condition causing absence of a portion or the entirety of one or both jaws. Our aim is to present a case of agnathia and review the literature regarding diagnosis, investigation and management. A 32-year-old G3P1 was referred to a fertility specialist after six years of secondary infertility. Karyotyping for both parents was normal, and they declined reproductive carrier screening. She conceived in her first cycle after laparoscopic ovarian drilling and non-invasive prenatal testing showed low risk of aneuploidy. Early fetal anatomy ultrasound was abnormal with a significantly hypoplastic or possibly absent mandible so she was referred to the Fetomaternal Unit. Ultrasound at 14+2 weeks showed a first branchial arch anomaly with an absent mandible and a cystic area inferior to the alveolus suggestive of agnathia. Fetal MRI at 15+6 weeks showed agnathia, aglossia or severe hypoglossia, and an anterior neck cyst presumably relating to ora-pharyngeal malformation or obstruction. The patient was reviewed by Clinical Genetics and a pediatric ENT surgeon, and the likely diagnosis of agnathia-otocephaly complex was discussed. Amniocentesis showed normal microarray. After extensive counselling regarding the guarded prognosis largely due to airway concerns, the couple elected to terminate at 21+5 weeks gestation. Although some gene mutations have been identified in association with agnathia, the cause of agnathia is not well understood. As craniofacial development involves multiple genes, there are likely other mutations as well as non-genetic etiologies that play a role. Agnathia-otocephaly complex is a severe malformation characterised by agnathia, melotia and microstomia with aglossia. Occurring in 1 in 70,000 births, the cause is likely multifactorial with both genetic and teratogenic factors. Investigation via genetic testing with chromosome microarray and whole exome sequencing can provide further insight when counselling for future pregnancies.