| Otocephaly | |
|---|---|
| Other names | Agnathia-otocephaly complex,[1] dysgnathia complex,[1] holoprosencephaly–agnathia,[1] |
 | |
| Female infant with otocephaly | |
| Specialty | Medical genetics |
| Symptoms | Absence of mandible (agnathia), small or absent mouth (microstomia), fused ears below chin (synotia), holoprosencephaly |
| Usual onset | 23rd–26th day of gestation (Carnegie stage 10) |
| Causes | Genetic |
| Diagnostic method | Prenatal ultrasound |
| Differential diagnosis | Treacher Collins syndrome, Goldenhar syndrome, Möbius syndrome |
| Prognosis | Stillbirth or miscarriage |
| Frequency | 1:70,000 |
Otocephaly, also known as agnathia–otocephaly complex, is a very rare and lethal cephalic disorder characterized by the absence of the mandible (agnathia), with the ears fused together just below the chin (synotia). It is caused by a disruption to the development of the first branchial arch. It occurs in every 1 in 70,000 embryos.