OMIM ID:
Fibrosis of Extraocular Muscles with Synergistic Divergence
Alternate Names
Defective Genes
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
Inheritance
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
Autosomal dominant disorders require only one mutation for the disease to be expressed. Since an affected parent has two chromosomes, only one of which has the mutant gene, parents can expect that half (50%) of their children will receive that one and inherit the disease. It is common for individuals that inherit the mutation, however, to not have evidence of the disease (nonpenetrance).
Autosomal dominant inheritance leads to a vertical pattern of transmission