Nephroblastomatosis and loss of WT1 expression associated with trisomy 13.

Trisomy 13 (Patau's syndrome) is a rare finding in newborns. The life span of babies affected by this chromosome abnormality is severely shortened, and multiple, partly severe malformations occur. In this study, we report on an unborn with trisomy 13 (artificially aborted on the 24th week) which showed, among other typical deformities, bilateral nephrogenic rests (nephroblastomatosis). Using molecular analysis, a loss of Wilms' tumor gene 1 (WT1) transcript and a biallelic expression of insulin growth factor 2 (IGF2) could be revealed. To our knowledge, this is the first reported case of trisomy 13 which showed this type of anomaly and gene expression findings.