PHENOTYPIC HETEROGENEITY MAY OCCUR IN CONGENITAL FIBROSIS OF THE EXTRAOCULAR-MUSCLES

Background/aims-Congenital fibrosis of the extraocular muscles (CFEOM) is an autosomal dominant, non-progressive disorder characterised by c ongenital ptosis and external ophthalmoplegia. CFEOM has previously be en divided into several clinical entities; general fibrosis syndrome, strabismus fixus, vertical retraction syndrome, and congenital fibrosi s of the inferior rectus. The purpose of this study was to identify fa milies with CFEOM in this geographical region in order to perform a st udy of the clinical presentation of this disorder and to estimate its minimum prevalence in the population. Methods-Four families were ident ified with CFEOM in the Wessex region from whom a full history with a pedigree was obtained. All individuals underwent ophthalmological exam ination. Results/conclusion-This study shows that several of the CFEOM entities can be present within one family suggesting that these are v ariants of the same condition. It is suggested that subclassification is, therefore, not appropriate. The minimum prevalence of this disorde r was found to be 1/230 000.