title: Concordant bilateral Duane's Retraction Syndrome (type 1) in female monozygotic twins.
abstract: We report a single case study of concordant bilateral Duane's Retraction Syndrome (DRS) (type 1) in female monozygotic (MZ) twins aged 47 years. The twin pair were recruited through the Australian Twin Registry as part of a twin study on myopia. This twin pair were full term and had a similar birth weight: 2.27 kg and 1.81 kg in twin 1 and twin 2, respectively. There was no report of any other childhood medical conditions in either twin. Both twins had an equal amount of restriction in right and left abduction. Narrowing of the palpebral fissures and globe retraction in right and left adduction was also observed in both twins. To our knowledge this is the first case to report concordant bilateral DRS (type 1) in female MZ twins. The concordance for the presence of DRS and associated clinical signs observed in this MZ twin pair supports a genetic origin to DRS.
authors.forename: Mohamed
authors.initials: M
authors.lastname: Dirani
authors.forename: Matthew
authors.initials: M
authors.lastname: Chamberlain
authors.forename: Pam
authors.initials: P
authors.lastname: Garoufalis
authors.forename: Christine
authors.initials: C
authors.lastname: Chen
authors.forename: Robyn H
authors.initials: RH
authors.lastname: Guymer
authors.forename: Paul N
authors.initials: PN
authors.lastname: Baird
mesh_terms: D004200:Diseases in Twins; D004370:Duane Retraction Syndrome / Q000235:genetics*; D005133:Eye Movements; D005260:Female; D007839:Functional Laterality; D006801:Humans; D008875:Middle Aged; D014430:Twins, Monozygotic / Q000235:genetics*; D015348:Vision, Binocular; D014792:Visual Acuity