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Acrofacial dysostosis is an umbrella term for several
apparently distinctive genetic modifications. The disorder is characterized
by distinctive craniofacial malformations, especially involving severe
mandibular hypoplasia and preaxial and postaxial limb defects.
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There are six types of acrofacial dysostosis.
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Acrofacial dysostosis, Nager type
(mandibulofacialdysostosis, split-hand deformity-mandibulofacial dysostosis)
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Acrofacial dysostosis lethal type of Rodriguez
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Acrofacial dysostosis, Weyers type (Weyers syndrome II)
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Acrofacial dysostosis postaxial, Miller type (Miller syndrome)
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Acrofacial dysostosis, Catania type
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Acrofacial dysostosis, Palagonia type
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All acrofacial dysostosis types
are inherited as either autosomal dominant or recessive pattern.
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Nager acrofacial dysostosis is a rare hereditary disorder marked by unusual facial development. Cleft
lip/palate, defective development of bones in the jaw and arms, smaller than
normal thumbs, hearing loss, and ear deformities are characteristics of this
disorder.
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Acrofacial dysostosis lethal type of Rodriguez is inherited as an autosomal recessive trait and is characterized by small
stature, severe mandibular hypoplasia (micrognathia), phocomelia and
oligodactyly of the upper limbs, absence of fistula, microtia, and cleft
palate. Limb deficiencies are predominantly preaxial. The skin is thin and
atrophic, vessels can be seen over the trunk, and elastosis perforans is
present. There is a severe hypoplasia of the shoulder and pelvic girdles.
Other features are severe internal organ anomalies, including
arrhinencephaly and abnormal lung lobulation. The cardiovascular system
presents congenital anomalies. The disorder is associated with early
lethality. Most patients die of respiratory complications during the
neonatal period, partly because of the presence of severe mandibular
hypoplasia.
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Weyers acrofacial dysostosis is present from birth, affects both sexes, and is characterized by
postaxial polydactyly of the hands and feet, hexadactyly and fusion of fifth
and sixth metatarsals and metacarpals and bony clefts of the mandibular
symphysis. Other features include orodental anomalies, hypoplastic and
dysplastic nails, short stature, micrognathia, small mouth, hypoplasia of
the larynx. Congenital heart defect may be present.
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Miller acrofacial dysostosis is thought to be inherited as an autosomal recessive trait and is apparent
at birth. It is characterized by postaxial acrofacial dysostosis, which is
defined by its postaxial limb deficiency. Craniofacial malformations, malar
hypoplasia, severe micrognathia, cleft palate, small, protruding,
“cup-shaped” ears, colobomas, drooping of the lower eyelids, and ectropion
are seen. The limb abnormalities in infants and children may include severe
hypoplasia, syndactyly, and/or absence of certain fingers and toes (e.g.,
fifth digits and, in some cases, fourth and third digits). Hypoplasia of the
ulna and radius causes the forearms to appear unusually short.
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Catania acrofacial dysostosis was reported in 1993 as a “new” form of acrofacial dysostosis. It is
characterized by mild intrauterine growth retardation and postnatal
shortness of stature, severe microcephaly, widow's peak, mandibulofacial
dysostosis without cleft palate, mild preaxial, and especially more
conspicuous postaxial upper limb involvement with short hands, simian
creases, and mild interdigital webbing. Other features include genitourinary
and gastrointestinal dysfunctions, ...