Abstract
Purpose::
To describe the clinical presentation and to identify the genetic basis for one Chinese pedigree of congenital fibrosis of the extraocular muscles (CFEOM).
Methods::
Four generations of a Chinese family with CFOEM had complete ophthalmologic examination to identify those individuals with the characteristic clinical features of bilateral ptosis and restrictive ophthalmoplegia. Data recorded on each patient includes sex, age, best corrected visual acuity, width of palpebral fissure, levator function, aberrant innervation, presence or absence of face up position, eye position, eye motility and associated non-ophthalmologic clinical features. Blood was drawn from all patients for genetic studies.
Results::
Twenty one members of the four generation family were examined which revealed a pedigree with autosomal dominant pattern of inheritance. Of these, nine individuals (five females and four males) demonstrated features consistent with CFEOM: bilateral, congenital, non-progressive ptosis with hypotropia, and exotropia. The degree of exotropia and hypertropia was measured in 11 eyes with mean exotropia of 34.5º (ranging between15 and 45º), and a mean hypertropia of 15.6º (ranging between15 and 20º). Mean vertical palpebral fissure distance in the affected patients was 4.1 mm (ranging between 2 and 8 mm) with unaffected family members averaging 9.6 mm (ranging between 7 and 12 mm). Six affected individuals exhibited no levator function, two patients had 2 mm and one had 1 mm of levator function. Seven patients exhibited aberrant innervation. All patients demonstrated the typical face up posture. Of the 9 eyes tested for ocular motility, 6 eyes had no movement, 2 eyes had limited (<15º) movement and one eye had horizontal movement between 15º and 45º. In addition to these typical ophthalmologic findings, all affected patients had dental aplasia (complete absence of teeth).
Conclusions::
We describe a novel Chinese pedigree of CFEOM with associated dental aplasia and autosomal dominant pattern of inheritance. Genetic studies, currently in progress, will hopefully identify the genetic abnormality responsible for this phenotype and aid in the development of better diagnostic and treatment modalities.
Keywords: strabismus • extraocular muscles: development • gene mapping