Aniridia usually occurs in isolation, but may also occur as part of the WAGR contiguous gene deletion syndrome, which includes Wilms tumor, aniridia, genitourinary abnormalities, and mental retardation.
The WAGR contiguous gene deletion syndrome is a combination of Wilms tumor, Aniridia, Genito-urinary abnormalities, and growth and mental retardation which is invariably associated with an 11p13 deletion.
The remaining four had chromosomal rearrangements: an unbalanced translocation, t(11;13), with a deletion including the WAGR (Wilms' tumor, aniridia, genitourinary abnormalities, and mental retardation) region, and three balanced rearrangements with what appear to be position effect breakpoints 3' of PAX6: (a) a t(7;11) with the 11p13 breakpoint approximately 30 kb downstream of PAX6, (b) a dir ins(12;11) with a breakpoint >50 kb from PAX6, and (c) an inv(11)(p13q13) with a breakpoint >75 kb downstream of PAX6.
Two eSTS markers have been further mapped with respect to a yeast artificial chromosome (YAC) contig close to the brain-derived neurotrophic factor (BDNF) gene and thus provide potential candidate genes for the mental retardation phenotype of WAGR (Wilms' tumor, aniridia, genitourinary abnormalities and mental retardation) syndrome.
All four del(11)(p13) cases presented with WAGR, a complex syndrome associated with a predisposition to Wilms' tumor (WT), aniridia (A), genitourinary abnormalities (G), and mental retardation (R).
The WAGR (Wilms tumor, aniridia, genitourinary anomalies, and mental retardation) region has been assigned to chromosome 11p13 on the basis of overlapping constitutional deletions found in affected individuals.