Hemifacial microsomia and the branchio-oto-renal syndrome.

Hemifacial microsomia (HFM) and the branchio-oto-renal syndrome (BOR) are both associated with malformations of the external ears; preauricular tags, pits, or sinuses; and conductive or mixed hearing loss. Other overlapping features have been described, including cervical appendages containing cartilage in HFM, and facial paresis in BOR; however, the significance of these findings has not been discussed by previous authors. The purpose of this paper is to describe four additional propositi with overlapping features of BOR and HFM. In two cases there is a positive family history of either first and second branchial arch anomalies or malformation of the kidney. Two cases appear to be sporadic. The overlapping clinical features suggest that in some families HFM may constitute a component toward the severe end of the spectrum of the autosomal dominant BOR syndrome. The empiric recurrence risk for HFM was 3% in one study. If our interpretation of these reported cases is correct, genetic recurrence risks for individuals in these families may fall in the range of an autosomal dominant condition. Since expression of both conditions varies widely, and minor manifestations may be overlooked, the importance of careful evaluation of first- and second-degree relatives is emphasized.