WT1 gene mutations in Chinese children with early onset nephrotic syndrome.

In Chinese children with steroid-resistant nephrotic syndrome (SRNS), it was reported that NPHS2 mutation was detected in 4.3%, which was lower than that in Caucasians (10-30%). However, there were no data on WT1 mutation in nephrotic syndrome (NS), especially in early-onset NS of Chinese children. Thus, a study, which enrolled 36 Chinese children with early-onset (before 3 y old) NS and steroid resistance if failing steroid therapy (early-group), was conducted. As control, 35 children with SRNS and with disease onset age after 3 y old were also analyzed (control-group). WT1 gene was examined by PCR and direct sequencing. The result showed that in the early-group 6/36 (16.7%) were detected with WT1 mutations. Further analysis according to different onset age revealed that the mutation detection rates of WT1 were 26.3% (5/19), 6.3% (1/16), and 0 (0/1) in children younger than 1 y, 1-2 y, and 2-3 y, respectively. In control-group, no WT1 (0/35) mutation was detected. WT1 mutation combined with NPHS2 variant was detected in a girl. In conclusion, WT1 mutations seemed more common in Chinese children with early-onset NS.