We report on PAX6 alleles associated with a clinical diagnosis of classical aniridia in 81 affected individuals representing 66 families. Allelic variants expected to affect PAX6 function were identified in 61 families (76 individuals). Ten cases of sporadic aniridia (10 families) had complete (8 cases) or partial (2 cases) deletion of the PAX6 gene. Sequence changes that introduced a premature termination codon into the open reading frame of PAX6 occurred in 47 families (62 individuals). Three individuals with sporadic aniridia (3 families) had sequence changes (1 deletion, 2 run-on mutations) expected to result in a C-terminal extension. An intronic deletion of unknown functional significance was detected in one case of sporadic aniridia (1 family), but not in unaffected relatives. Within these 61 families, single nucleotide substitutions accounted for 30/61 (49%), indels for 23/61 (38%), and complete deletion of the PAX6 locus for 8/61 (13%). In five cases of sporadic aniridia (5 families), no disease-causing mutation in the coding region was detected. In total, 27 unique variants were identified that have not been reported in the LOVD database. Within the group assessed, 92% had sequence changes expected to reduce PAX6 function, confirming the primacy of PAX6 haploinsufficiency as causal for aniridia.