Phenotypic Variability in a Three–Generation Family With Duane’s Syndrome

Abstract

Abstract: : Clinical variability in a three–generation family with Duane’s syndrome Purpose: Duane’s retraction syndrome is characterised by a congenital deficiency in abduction of the affected eye, variable limitation of adduction, globe retraction, narrowing of the palpebral apertures on adduction and abnormal oblique movements. Familial cases of Duane’s syndrome have been reported. We report a pedigree of three generations with variable clinical signs in affected individuals. Methods: 22 patients in a family of three generations of mean age 21.7 years (range 6 years to 70 years) were examined. Detailed ophthalmological assessment included assessment of vision, binocularity, and clinical and video recordings of ocular motility. Blood samples and mouth swabs were obtained for DNA analysis. Results: Seven individuals (four males and three females) were identified with Duane’s syndrome. There was one pair of twins where twin A had clinical features of Duane’s syndrome and twin B had an esotropia. Two children of twin A had Duane’s syndrome and three of twin B’s children had an esodeviation. All patients with strabismus had symptoms of diplopia. Amongst individuals with Duane’s syndrome, one had an abnormal head posture, one had an esotropia and there was one individual with no palpebral aperture changes. Conclusions: We report a family with Duane’s syndrome where two affected twins and their children had Duane's syndrome or strabismus. Our study suggests that familial Duane’s syndrome has variable expressivity and phenotypic features.

Keywords: ocular motor control • eye movements • binocular vision/stereopsis