Duane syndrome

Duane-Radial Ray Syndrome

Clinical Characteristics
Ocular Features: 

Most individuals have features of Duane’s anomaly, sometimes unilaterally.  Optic pallor with poor vision has been described in well-studied patients who also had thinning of the retinal nerve fiber layer.  The optic disk may appear hypoplastic.  Visual evoked potentials and pattern ERG amplitudes are decreased.

Other less common ocular features are microcornea, microphthalmia, ophthalmoplegia, hypertelorism, cataracts, epicanthal folds, colobomas, and chorioretinal scars.

Systemic Features: 

The systemic features are inconsistent (variable expressivity) with most patients having some variation of hypodactyly, polydactyly, syndactyly, and malformation of the hands.  The thumb is the most common digit involved and this is often associated with thenar hypoplasia.  Other skeletal features of the radial ray syndrome including absence of the radial and ulnar bones are variably present.  Hearing loss is described as sensorineural in etiology but malformations of the pinnae and external meatus are sometimes present.

Kidney anomalies include horseshoe malformations, abnormal rotation, ectopia, small size, vesicoureteric reflux, and pelvicalyceal dilatation.

Genetics

This is an autosomal dominant disorder due to heterozygous mutations in the SALL4 gene (20q13.2).

This syndrome is sometimes confused with the Holt-Oram syndrome but the latter is the result of mutations in a different gene and lacks ocular and renal abnormalities.  Duane syndrome 1 and 2 may also occur as isolated conditions.

The considerable clinical heterogeneity has led to alternate titles for this syndrome. For example, what is sometimes called the IVIC syndrome (147750) with similar features is also caused by mutations in this gene.  Duane-radial ray syndrome has also been called Okihiro syndrome. 

 

Pedigree: 
Autosomal dominant
Treatment
Treatment Options: 

Treatment is symptomatic in most cases although reconstructive surgery may be helpful for severe hand deformities.  Low vision aids may be beneficial.  

References
Article Title: 

Wildervanck Syndrome

Clinical Characteristics
Ocular Features: 

The ocular manifestations of this disorder are limited to Duane syndrome and abducens palsy.

Systemic Features: 

Congenital perceptive deafness is due to a bony malformation of the inner ear.   A Klippel-Feil cervical malformation consisting of a low hairline, limited neck mobility, and short neck secondary to cervical fusion (usually involving the atlas and axis) is present as well. The presence of neck webbing (pterygium colli) can exaggerates the short neck appearance.  Diastematomyelia of the lower medulla and cervical cord has been reported in a child who also had tonsillar herniation and hydrocephalus of all three ventricles.

A variety of inconsistent anomalies including spine deformities, cardiac malformations, anomalies of the genitourinary system and somatic growth retardation have also been reported.

The KFS malformation can occur alone or in association with other syndromes.

Genetics

This is a heritable syndrome that affects primarily females.  The inheritance pattern, however, is not clear.   Sex-linked dominance with lethality in the male has been proposed but others have suggested multifactorial inheritance.  Most cases occur sporadically and no responsible genes have been identified.

Treatment
Treatment Options: 

Patients might benefit from cochlear implants as well as strabismus surgery to correct a head turn.

References
Article Title: 
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