en Narrative Review Narrative Review Aniridia is a congenital pan-ocular, bilateral disorder. The term aniridia is a misleading misnomer, since at least a rudimentary iris is always present. Varied forms range from almost total absence to only mild hypoplasia of the iris. It is inherent in a number of syndromes, including Wilms tumor Aniridia-Genital anomalies-retardation (WAGR). Aniridia has been shown to be associated with mutations in the<i> PAX6</i> gene, located on chromosome 11p13, telomeric to the Wilms&rsquo; tumor predisposition gene (<i>WT1</i>). The pair box gene 6 (<i>PAX6</i>) situated at 11p13 has been confirmed to be the leading gene associated with aniridia. The <i>PAX6</i> mutation is present in individuals worldwide and has been studied in Indian, Malaysian, Chinese and Mexican families. Several categories of <i>PAX6 </i>mutations include: nonsense mutations, splicing mutations, frameshift mutations (deletion or insertion), in-frame insertion or deletion, missense mutations and run-on mutations. A novel <i>de novo</i> frameshift mutation in <i>PAX6</i> most possibly occurred in the paternal gamete. Mutation in <i>PAX6</i> brings about amino acid substitution for instance proline to glutamine. Deletion of 11p13 involves the <i>PAX6</i> (aniridia) locus and the adjacent <i>WT1</i> (Wilms tumor) locus. Haploinsufficiency at the <i>PAX6</i> locus brings on aniridia, a pan-ocular eye condition characterized by iris hypoplasia and various other anterior and posterior eye defects, subtle hypogonadotropic hypogonadism and borderline Growth Hormone (GH) deficiency. Aniridia may also be affiliated with retinal tears and detachments. Electroretinograms (ERGs) done in aniridia illustrate definite retinal dysfunction. Other clinical aspects related to aniridia are ptosis with reduced levator function and anterior polar cataracts. The <i>PAX6 </i>gene mutation was also associated with early-onset diabetes mellitus and aniridia. Aniridia combined with zonular cataract and polydactyly was also described in a patient with Bardet-Biedl syndrome. Aniridia with sensorineural deafness (cochlear) and aplasia of the patella was also reported; an autosomal-dominant inheritance with 100% penetrance. The WAGR syndrome is associated with obesity. Because of all the associations with other diseases as mentioned above, ophthalmologists should pay more attention to aniridia as a sign of a systematic disease. As aniridia is a global disease and has been reported in all five continents and several countries with different ethnic groups, herein we reviewed this important disorder. Aniridia, Genetic, PAX6, Congenital, Disease 12 17 http://jpr.mazums.ac.ir/browse.php?a_code=A-10-30-27&slc_lang=en&sid=1 Reza Jafari rezaj76@yahoo.com 10031947532846002202 10031947532846002202 Yes Department of Ophthalmology, Bouali Sina Hospital, Mazandaran University of Medical Sciences, Sari, IR Iran Ahmad Ahmadzadeh Amiri 10031947532846002203 10031947532846002203 No Department of Ophthalmology, Bouali Sina Hospital, Mazandaran University of Medical Sciences, Sari, IR Iran