In the sentence extracted from biomedical literature, identify all the disease entities. The required answer format is the same sentence with HTML <span> tags to mark up specific entities. 
### Entity Markup Guides:
Use <span class="disease"> to denote a disease.

### Input Text: Aniridia in man and Small eye in mice are semidominant developmental disorders caused by mutations within the paired box gene PAX6 .
### Output Text:
<span class="disease">Aniridia</span> in man and Small eye in mice are <span class="disease">semidominant developmental disorders</span> caused by mutations within the paired box gene PAX6 . 