Fibrose Congênita dos Músculos Extraoculares: estudos genéticos de onze membros afetados em três gerações distintas de uma família brasileira

Abstract

Congenital fibrosis of the extraocular muscles (CFEOM) is the term used to describe an inherited entity that presents with non-progressive ocular motility disorder associated with ophthalmoplegia, strabismus and ptosis. The CFEOM can be classified into five types. The classification is based on signs, symptoms and genetic tests1,2. The CFEOM type 1 and type 3 have autosomal dominant inheritance and type 2, type 4 and type 5 have autosomal recessive inheritance. The suspicion of this pathology is important in cases of congenital ptosis associated with ophthalmoplegia1,2,3. Eleven members of a family accompanied at the ambulatory of neuromuscular diseases of the Hospital das Clínicas at the Federal University of Minas Gerais (UFMG), presented symptomatology suggestive of CFEOM. The index case EXOMA was performed and it was possible to identify a mutation of the KIF21A gene. The result was confirmed by the method of SANGER sequencing and the same mutation was identified in the other members of the family. A complete ophthalmologic examination was performed, including strabismus and ocular plastic surgery assessments, and in view of the symptomatology of the patients studied and of the mutation found, it was possible to classify the CFEOM in type 1. Since it is a rare entity, not yet described in the Brazilian population and unknown by most physicians, the study is justified to divulge this clinical entity and to emphasize the importance of performing a correct diagnostic and therapeutic approach and as early as possible to guarantee a psychomotor development without damages, since the vision is one of the most explored senses during development4.