The aniridia-Wilms' tumor syndrome has recently been found to closely related to an interstitial deletion of the short arm of chromosome 11. A mentally-retarded, one year and ten months old boy with the aniridia-Wilms' tumor syndrome was reported. He was recognized shortly after birth to have bilateral congenital aniridia and nystagmus. There was no family history of aniridia. After right nephrectomy for Wilms' tumor, he received Linac irradiation to the tumor bed, and Actinomycin D and Vincristin were given according to the NWTS protocol. One and a half years after operation, another tumor was detected in his left kidney, and he died 3 months later. Chromosomal analysis using trypsin-Giema banding was performed on prometaphase chromosomes from the peripheral lymphocytes culture, and the karyotype designation was determined to be 46, XY, del (11) (p11.1→p13). His mother and sister had normal karyotype. A patient with aniridia and del (11p13) is well known to have a high risk for the development of Wilms' tumor or gonadoblastoma. Seven cases of the aniridia-Wilms' tumor syndrome have been reported in the Japanese literature up to date, but the chromosomal deletion has not been described. In the world literature, 23 cases of aniridia with del (11p13) with or without Wilms' tumor have been reported: 13 with Wilms' tumor, 2 with gonadoblastoma, and 8 with no tumor. The etiology of aniridia-Wilms' tumor syndrome was discussed.
