As far as is known, this is the smallest deletion as-yet described encompassing the WT1 gene and was detected only once in a total of 32 Portuguese patients with isolated uni- or bilateral cryptorchidism.
Of the 12 cases with multiple tumors, 1 exhibited a constitutional 11p13 deletion and a somatic stop mutation in exon 4 of the WT1 gene and 2 harbored constitutional mutations in the WT1 gene: a pre-mature stop codon in exon 6 in a boy with bilateral cryptorchidism and bilateral Wilms' tumors and an intragenic deletion in a girl with bilateral WT.