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: We have identified 14 families with ataxia - telangiectasia ( A - T ) in which mutation of the ATM gene is associated with a less severe clinical and cellular phenotype ( approximately 10 % - 15 % of A - T families identified in the United Kingdom ) .
### Output Text:
We have identified 14 families with <span class="disease">ataxia - telangiectasia</span> ( <span class="disease">A - T</span> ) in which mutation of the ATM gene is associated with a less severe clinical and cellular phenotype ( approximately 10 % - 15 % of <span class="disease">A - T</span> families identified in the United Kingdom ) . 