Clinical variability in a three‐generation family with Duane’s syndrome

Abstract

Abstract Purpose The majority of Duane syndrome cases are sporadic in origin with only 2‐5% patients showing a familial pattern. Only a few large families have been reported. The purpose of this study is to report the clinical presentations, abnormalities of ocular motility, and strabismus in 3 generations of a family with Duanes syndrome. Methods 22 members of a family of three generations (age range 6 years to 70 years) were examined. Detailed ophthalmologic assessment included assessment of vision, binocularity, and video recordings of ocular motility. Results Unilateral Duane syndrome type 1 was noted in the left eye of a lady in the first generation of the pedigree. In the second generation, of the 4 subjects examined, two females had esotropia with diplopia, one male had minimal bilateral abduction deficit with endpoint nystagmus and one sibling was normal. 12 subjects from the third generation were examined. Two of them had unilateral Duane’s syndrome. Two children had minimal abduction deficit with endpoint nystagmus. Three subjects had esotropia and diplopia requiring surgery. The mother of one of the affected subject had normal eye movements. Conclusion This large family with Duane syndrome appears to have a dominant form of inheritance with variable penetrance and expressivity. The skipped generation indicates unaffected carrier state. The variable phenotypic expression seen in this family suggests that classical Duane syndrome could be one end of a spectrum of eye movement disorders comprising esotropia, abduction deficits and globe retraction; the other end being normal ocular motility.