The extra digit. A pointer to the eye?

The syndrome associated with an extra digit which is commonly seen by the ophthalmologist is that of Laurence-Moon-Biedl, with its well-known association with retinal dystrophy. However, there are several other syndromes in which there is polydactyly and an ocular malformation. Many have colobomata and microphthalmos. Other syndromes show various orbital and eyelid abnormalities, such as ptosis, hypertelorism, and lateral displacement of the canthi. In three syndromes other than the Laurence-Moon-Biedl there is a retinal dystrophy. In Trisomy 13 there is a severe retinal dysplasia, and in Bloom's syndrome excrescences on Bruch's membrane have been described. There have been several cases of asphyxiating thoracic dystrophy (Jeune's syndrome) described with a retinal dystrophy, and we present a case of the closely-related Ellis-van Creveld syndrome with a retinal dystrophy. We also present a case with a chromosomal defect (an addition to the short arm of chromosome 2), polydactyly, and a retinal dystrophy.