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: An animal model for Norrie disease ( ND ) : gene targeting of the mouse ND gene .
### Output Text:
An animal model for <span class="disease">Norrie disease</span> ( <span class="disease">ND</span> ) : gene targeting of the mouse <span class="disease">ND</span> gene . 