An extremely rare and fatal association syndrome, characterized by absence of the mandible, cerebral malformations with facial anomalies related to a defect in cleavage in the embryonic brain (e.g. synophthalmia, malformed and low-set ears fused in midline (otocephaly), agenesis of the olfactory bulbs, microstomia, hypoglossia/aglossia) and situs inversus partialis or totalis.

Distance between the commissures of the mouth more than 2 SD below the mean. Alternatively, an apparently decreased width of the oral aperture (subjective).