Acrofacial Dysostosis 1, Nager Type
Acrofacial Dysostosis 1, Nager Type
A heterogeneous group of autosomal dominant disorders—globally termed Nager acrofacial dysostosis (NAFD)—characterised by defects of cranial neural crest and limb development; NAFD comprises two general groups of defects involving either the upper limbs or craniofacial defects in the form of mandibulofacial dysostosis.Clinical findings The upper limb defects are characteristic, with radio-ulnar synostosis and triphalangeal thumbs and index finger; 5th fingers may be short and clinodactylic; absence of thumbs may be associated with distal hypoplasia or absence of radii with shortness and bowing of ulnae resulting in a radial club hand with or without antecubital webbing; phocomelia is rare. Mandibulofacial dysostosis is also highly characteristic, with downward slant of palpebral fissures, ptosis of upper lids, coloboma of lower lids, deficiency of eyelashes of the medial 1⁄3 to 2⁄3 of the lower eyelids, hypoplasia of the malar eminences and zygomata, hypoplasia of maxilla with cleft of secondary palate or highly-arched palate, absence of velum (rarely with choanal atresia), and an extension of a “tongue” of temporal hair down the sides of the cheeks.