THE IMPORTANCE OF DNA ANALYSIS IN SPORADIC ANIRIDIA

Total aniridia was found in a 2-month-old baby boy. Otherwise the baby was healthy. Ophthalmological examination of the elder sister, parent s and paternal grandparents revealed no abnormalities. There was no co nsanguinity between the parents. Hence, the aniridia was considered sp oradic, and the possibility of Wilms' tumour had to be taken into cons ideration. The chromosomes of the baby were normal, as judged by conve ntional cytogenetic analysis. In addition, DNA analysis demonstrated t hat there was no subchromosomal deletion in band 11p13, spanning the a niridia-Wilms' tumour region. Therefore, we conclude that the genetic defect leading to aniridia is confined to the aniridia locus and that the child has no increased risk of developing Wilms' tumour.