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: The gene mutated in ataxia - telangiectasia ( AT ) patients , denoted ATM , encodes a putative protein or lipid kinase .
### Output Text:
The gene mutated in <span class="disease">ataxia - telangiectasia</span> ( <span class="disease">AT</span> ) patients , denoted ATM , encodes a putative protein or lipid kinase . 