Further observations of ocular pathology in trisomy 9.

The ocular pathology in a new patient with mosaic trisomy 9 comprised major anomalies and contrasted sharply with the findings in a previous case reported by us. The ocular changes in this case were, in essence, indistinguishable from those encountered in the most severe form of trisomy 13. Similarities to trisomy 18 and 21 were further evidence of the overlap of ocular findings in autosomal trisomies. There is increasing evidence that most, if not all, chromosomes have some role in regulating ocular embryogenesis.