Holoprosencephaly spectrum, ano/microphthalmia, and first branchial arch defects: evidence for a new disorder.

We report on three unrelated Brazilian patients with a holoprosencephaly phenotype, with variable central nervous system involvement, ano/microphthalmia, and first branchial arch anomalies. The features of these patients show a striking similarity to those of the patients reported by Guion-Almeida et al. (1999) and Ribeiro et al. (2005), thus confirming the existence of this rare condition. All cases are isolated and the etiology remains unknown.