Evidence of genetic heterogeneity in autoomal receive congenital fibroi of the extraocular mucle

PURPOE: Autoomal receive congenital fibroi of the extraocular mucle (CFEOM2) ha been decribed in familie from audi Arabia. Affected individual have ptoi and exotropic ophthalmoplegia, and their dieae ha been mapped to chromoome 11q13. Here, we decribe the phenotypic finding in a imilarly affected Yemenite family and analyze the family for linkage to the CFEOM2 locu, a well a to the autoomal dominant CFEOM1 and CFEOM3 loci on chromoome 12cen and 16q24, repectively. METHOD: The family wa acertained through two affected daughter. There are four unaffected ibling, and the parent are conanguineou. Each family member wa examined, and linkage analyi wa performed uing marker from the CFEOM1, CFEOM2, and CFEOM3 loci. REULT: Both affected daughter have congenital bilateral ophthalmoplegia. The 15-month-old proband ha retrictive exotropia. he fixate with either eye in abduction and with a compenatory head turn to the oppoite ide. Her 4-year-old iter ha a mall exotropia and everely limited eye movement. All other family member have normal ophthalmologic examination. Genetic analyi excluded linkage of the family’ dieae to the CFEOM2 and CFEOM3 loci. A lod core of 2.0 (the maximum poible, given the family ize and tructure), wa obtained at the CFEOM1 locu, and the allele reduced to homozygoity in both affected daughter and none of the other children. CONCLUION: Thee data etablih that there i genetic heterogeneity in autoomal receive CFEOM and ugget that thi econd receive locu may be allelic to the autoomal dominant CFEOM1 locu at 12cen.