Acromelic frontonasal dysostosis (AFND; MIM 603671) is a rare autosomal dominant disorder with distinct craniofacial, central nervous system and limb malformations. Typical craniofacial findings include severe frontonasal malformation with median facial cleft, marked separation of the nares, significant hypertelorism, and a carp shaped mouth. Central nervous system findings include severe intellectual disability, interhemispheric lipoma, agenesis of the corpus callosum, absent olfactory bulbs, pituitary abnormalities, and periventricular nodular heterotopia. Limb malformations include tibial hypoplasia, patellar hypoplasia, and preaxial polydactyly of the feet. AFND is caused by mutations in the ZSWIM6 gene, which encodes zinc finger SWIM domain-containing protein 6. Certain ZSWIM6 mutations can cause a phenotype consisting mainly of profound intellectual disability without craniofacial and limb malformations.