Defined in 1975, branchio-oto-renal (BOR) syndrome is an autosomal dominant disorder consisting of branchial arch anomalies, hearing loss, and urinary tract malformations. It is the prototype of the non-chromosomal syndromes that have branchial arch anomalies as major clinical manifestations: BOR, branchio-otic (BO), branchio-otic-facial (BOF), and Townes-Brock syndromes. Subsequently, several clinical manifestations have expanded its phenotype. Retrospective analysis of 31020 families evaluated between January 2, 1982 and December 31, 1996 at the genetic clinics of the University of South Florida, showed seven probands with BOR/?BOR syndrome. Four of the probands and affected relatives had manifestations that further expanded the phenotype: gustatory lacrimation, hypospadias, imperforate anus, osteosclerosis, microcephaly, hypodontia, congenital vocal cord paresis, and congenital incomplete fixation of the transverse colon. Thus, BOR/ ?BOR syndrome appears to be a clinically and genetically heterogeneous multiorgan/system entity that manifests itself predominantly during organogenesis. Clinicians and researchers alike should be cognizant of the expanded phenotype and heterogeneity, while in the DNA laboratories the latter will be sorted out.