FRONTONASAL DYSPLASIA - ANALYSIS OF 21 CASES AND LITERATURE-REVIEW

Twenty-one patients with frontonasal dysplasia were studied. A 2:1 mal e-to-female sex ratio and increased paternal and maternal ages at the time of conception were found. The significance is uncertain because o f small sample size and lack of normal mean values for parental age in Brazil. Apparently, our series is the first to report macrocephaly (s ix cases). Our series also had a high frequency of patients with agene sis of the corpus callosum (12 cases), basal encephalocele (10 cases), lipoma of the corpus callosum (four cases), and mental deficiency (11 cases). Three patients had the combination of agenesis of the corpus callosum, mental deficiency, and micropenis. It is concluded that fron tonasal dysplasia is pathogenetically heterogeneous, representing a re gional defect which may not be a single developmental field or sequenc e. Causal genesis includes a dominantly inherited form, dup(2q), and a utosomal recessive Shanske syndrome, Of unknown genesis are two subset s of frontonasal dysplasia patients: 1) the combination of agenesis of the corpus callosum, tibial hypoplasia, and hallucal duplication and 2) ophthalmofrontonasal dysplasia or oculoauriculofrontonasal dysplasi a with associated ear tags and epibulbar dermoids.