The infant presents with agnathia associated with
cleft lip/palate, hypertelorism, and dysregulation of the sympathetic nervous
system. Holoprosencephaly is associated with agenesis of the corpus
Agnathia-holoprosencephaly is a complex anomaly of the
development of face and brain frequently associated with situs inversus and
Extremely rare (probably <20 cases have been described).
Agnathia-holoprosencephaly may be genetically
determined as an autosomal recessive trait by a single recessive gene. Three
reported cases had duplication of 6q and monosomy 18p.
Probably results from an inductive defect of the
prechordal mesoderm or failure of migration of neural crest mesenchyme into
the maxillary prominence during weeks 4 and 5 of gestation.
Agnathia-holoprosencephaly is a
developmental field complex anomaly that affects the development of the face
and brain and is frequently associated with situs inversus and visceral
anomalies. At birth, the infant presents with agnathia and other
craniofacial anomalies, such as cleft lip/palate, synotia (fusion of the
ears in the midline below the chin), synophthalmia (cyclopia), or
hypertelorism. Situs inversus must be ruled out. Magnetic resonance imaging
(MRI) scans may demonstrate (alobar) holoprosencephaly with agenesis of the
corpus callosum and other brain defects. Other anomalies may include
visceral anomalies such as aglossia or microglossia, and microstomia,
tracheoesophageal fistula, and congenital cardiac lesions. Prenatal
ultrasound examination may reveal intrauterine growth retardation, agnathia
(mandibular agenesis), or significant mandibular hypoplasia. Most patients
do not survive the first year of life, but survival longer than 1 year has
been described in isolated cases.
Neonates should be carefully
evaluated for associated visceral abnormalities. In particular, congenital
cardiac lesions should be ruled out by echocardiography. Mental and
neurologic status must be assessed for a thoughtful approach to induction.
Evaluate for signs of airway obstruction and difficult airway management
because of agnathia and other facial defects. Difficult tracheal intubation
must be anticipated when treating a child.
Because of difficult airway management,
spontaneous breathing should be maintained until the airway is secured.
Fiberoptic intubation may be required or, depending on the procedure, a
laryngeal mask airway can be used. However, be aware that mouth opening of
less than 1 cm has been described in several cases.
Anticholinergic drugs may assist in
reducing secretions in cases of difficult airway management.
Ozden S, Bilgic R, Delikara N, et al: The sixth clinical report of a
rare association: Agnathia-holoprosencephaly-situs inversus. Prenat Diagn
Pauli RM, Pettersen JC, Arya S, et al: Familial agnathia-holoprosencephaly.
Am J Med Genet
Bixler D, Ward R, Gale DD: Agnathia-holoprosencephaly: A developmental field
complex involving face and brain. Report of 3 cases. J Craniofac Genet
Dev Biol Suppl