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: A gene mutated in the human genetic disorder ataxia - telangiectasia ( A - T ) , ATM , was recently identified by positional cloning .
### Output Text:
A gene mutated in the human <span class="disease">genetic disorder</span> <span class="disease">ataxia - telangiectasia</span> ( <span class="disease">A - T</span> ) , ATM , was recently identified by positional cloning . 