Oculo-auriculo-vertebral spectrum and the CHARGE association: clinical evidence for a common pathogenetic mechanism.

We describe two infants with features of both the oculo-auriculo-vertebral spectrum (OAVS) and the CHARGE association (CA). Both patients are more severely affected than the typical patient with the OAVS. Each has facial asymmetry, mandibular hypoplasia, ear abnormalities, hearing impairment, microphthalmia, heart defects, and developmental delay. They also have features that are not characteristic of either OAVS or CA including torticollis, plagiocephaly, and heminostril. Based on the findings of these patients and other reported in the literature, there appears to be a significant overlap of features between OAVS and CA, and we suggest that these conditions in fact may be produced by the same pathogenetic mechanism. One such mechanism to explain the overlap of these disorders is that both conditions are part of the axial mesodermal spectrum, and represent a dysblastogenetic process. This mechanism may also explain the presence of some of the additional features not normally seen in OAVs and CA but seen in these two infants.