exotropia

Cerebral Palsy, Spastic Quadriplegic, 3

Clinical Characteristics
Ocular Features: 

One family with 4 affected sibs has been reported but without detailed information on ophthalmological findings.  Strabismus reported as exotropia in one individual, and "convergent retraction nystagmus" in another was present.  Supranuclear gaze palsy was described in one individual. 

Systemic Features: 

Borderline microcephaly has been reported.  Evidence for global neurologic disease, primarily spasticity, may be present as early as 3 months of age.  Intellectual disability ranges from borderline to severe.  Progression is somewhat variable but by the second decade there may be sufficient spastic quadriparesis and cognitive impairment that full time assistive care is required.  Dysarthria and dysphagia are also features and gastrostomy feeding tubes may be required to maintain nutrition.  Seizures are uncommon.

The MRI does not show major structural abnormalities and an EEG in one patient revealed only bifrontal spike-waves.

Genetics

This condition is caused by homozygous mutations in the ADD3 gene (10q24).

Pedigree: 
Autosomal recessive
Treatment
Treatment Options: 

No treatment is known.

References
Article Title: 

Mutations in gamma adducin are associated with inherited cerebral palsy

Kruer MC, Jepperson T, Dutta S, Steiner RD, Cottenie E, Sanford L, Merkens M, Russman BS, Blasco PA, Fan G, Pollock J, Green S, Woltjer RL, Mooney C, Kretzschmar D, Paisan-Ruiz C, Houlden H. Mutations in gamma adducin are associated with inherited cerebral palsy. Ann Neurol. 2013 Dec;74(6):805-14.

PubMed ID: 
23836506

Takenouchi-Kosaki Syndrome

Clinical Characteristics
Ocular Features: 

The ocular phenotype consists of mild ptosis, synophrys, exotropia, and eversion of the lower eyelids.  One of two reported patients was described as having bilateral retinal dysplasia and a falciform retinal detachment in one eye.  Visual acuity is significantly impaired.

Systemic Features: 

Affected individuals may be of normal birth weight but skeletal growth is subnormal and there is general developmental delay.  Congenial cardiac anomalies such as persistent ductus arteriosus may be present.  Lymphedema has been noted at one year of age and probably persists throughout life.  Protein-losing enteropathy secondary to intestinal lymphangiectasia was present in one individual.  The same patient had pericardial effusion, hydrothorax, and ascites.  Intellectual disability may be severe although there is no evidence of progression.  Neurosensory hearing loss has been described in one patient.

Thrombocytopenia is a consistent finding and has been described as early as one year of age.  Platelet numbers as low as 52,000/microL have been recorded and appear larger than normal. 

Genetics

Both unrelated female patients reported have heterozygous missense mutations in the CDC42 gene (1p36). 

Pedigree: 
Autosomal dominant
Treatment
Treatment Options: 

No treatment has been reported.

References
Article Title: 

Fibrosis of Extraocular Muscles with Synergistic Divergence

Clinical Characteristics
Ocular Features: 

This is an ocular motility disorder with restrictive ophthalmoplegia and anomalous eye movements.  Some individuals exhibit Marcus Gunn jaw winking and downgaze fixation along with ptosis.  MRI imaging may reveal hypoplasia of the oculomotor nerve and absence of the abducens nerve.  Sometimes one or more extraocular muscles are replaced with fibrous tissue.  Globe retraction may accompany the abduction movement.  Forced duction testing may reveal severe restriction and Bell's phenomenon may be absent.  Vertical nystagmus and jerky eye motions may accompany attempted fixation.  There is considerable asymmetry to the extraocular movements of the two eyes. 

Systemic Features: 

Some patients have oculocutaneous hypopigmentation.

Genetics

No specific mutation has been identified.  Several examples of parent to child transmission have been reported suggesting autosomal dominant inheritance.

Other nonsyndromal forms of congenital fibrosis of extraocular muscles include: CFEOM1 (135700), CFEOM2 (602078), CFEOM3C (609384), and CFEOM5 (616219), although the eye movement phenotype may vary.  See also Tukel CFEOM syndrome (609428).

Pedigree: 
Autosomal dominant
Treatment
Treatment Options: 

Ptosis and strabismus surgery may be of benefit.

References
Article Title: 

Fibrosis of Extraocular Muscles, CFEOM2

Clinical Characteristics
Ocular Features: 

This is a congenital, autosomal recessive, nonprogressive type of CFEOM which has been described in several consanguineous Middle Eastern families.  The responsible mutations are in a different gene than the one responsible for autosomal dominant CFEOM1 cases although some of the clinical features are similar.  However, in CFEOM2 the eyes are less likely to be infraducted and instead are often fixed in extreme abduction.  In addition, the phenotype is more variable with some eyes fixed in the 'neutral' position and others having more mobility than usually seen in CFEOM1 but the clinical heterogeneity is less than that seen in CFEOM3.  Ptosis is part of both phenotypes.  All patients have severe restrictions in ocular motility.  It has been suggested that CEFOM2 patients are likely to have involvement of both superior and inferior divisions of the oculomotor nerve whereas only the superior division is abnormal in CFEOM1.  Binocular vision is absent and amblyopia is common.  The pupils may be small and respond poorly to light. Refractive errors are common.

Based on visual field testing and ERG findings, it has been suggested that subnormal vision in CFEOM2 may be due to undescribed retinal dysfunction.  

Systemic Features: 

Mild facial muscle weakness may be apparent. 

Genetics

This is an autosomal recessive disorder caused by homozygous mutations in the PHOX2A gene at 11q13.3-q13.4.  Another more common form of CFEOM is the autosomal dominant CFEOM1 type (135700) in which the primary fixed deviation is infraduction. The third type is CFEOM3 (600638, 609384) which is clinically more heterogeneous. 

Other nonsyndromal forms of congenital fibrosis of extraocular muscles include: CFEOM3C (609384), CFEOM5 (616219), and CFEOM with synergistic divergence (609612).  See also Tukel CFEOM syndrome (609428).

Pedigree: 
Autosomal recessive
Treatment
Treatment Options: 

Restoration of normal ocular motility is difficult but cosmetic improvement is possible by correcting some of the ptosis with frontalis slings.  Corneal lubrication must be maintained and amblyopia should be treated. 

References
Article Title: 

Apert Syndrome

Clinical Characteristics
Ocular Features: 

In 10% of patients, keratitis and corneal scarring occur from the sometimes marked proptosis and corneal exposure.  Optic atrophy is present in over 20% of patients.  Strabismus, primarily exotropia, is found in more than 70% and various extraocular muscle anomalies may be detectable.  Usually the exotropia has a V-pattern with overaction of the inferior oblique muscles while the superior oblique is weak.  Amblyopia occurs in nearly 20%.  The lid fissures often slant downward and the eyebrows may be interrupted.

Systemic Features: 

This brachysphenocephalic type of acrocephaly is associated with syndactyly in the hands and feet.  Pre- and postaxial polydactyly may be present.  There is considerable variation in expression with some patients so mildly affected that they appear virtually normal, whereas others have extreme degrees of brachycephaly with high foreheads, midface hypoplasia, and proptosis secondary to shallow orbits.  Imaging often reveals one or more CNS anomalies such as defects of the corpus callosum, partial absence of the septum pellucidum, ventriculomegaly, and sometimes hydrocephalus.  A small but significant proportion of patients have some developmental delay and cognitive impairment.  Over 39% of patients have a normal IQ.

Genetics

This type of craniosynostosis is caused by mutations in the fibroblast growth factor receptor-2 gene, FGFR2, located at 10q26.13.  It is generally considered an autosomal dominant disorder based on familial cases but most occur sporadically.  A paternal age effect on mutations has been found.  The same gene is mutant in allelic disorders sometimes clinically separated and labeled Crouzon (123500) and Pfeiffer (some cases) (101600) syndromes.  Jackson-Weiss syndrome (123150) maps to the same locus.  However, this entire group has many overlapping features making classification on clinical grounds alone difficult.  Only Apert syndrome is caused by mutations in a single gene whereas other syndromes seem to result from mutations in multiple genes.

Pedigree: 
Autosomal dominant
Treatment
Treatment Options: 

No specific treatment is available for this disorder but exposure keratitis may require surveillance and therapy.

References
Article Title: 
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