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: X - Linked adrenoleukodystrophy ( ALD ) is a genetic disease associated with demyelination of the central nervous system , adrenal insufficiency , and accumulation of very long chain fatty acids in tissue and body fluids .
### Output Text:
<span class="disease">X - Linked adrenoleukodystrophy</span> ( <span class="disease">ALD</span> ) is a <span class="disease">genetic disease</span> associated with <span class="disease">demyelination of the central nervous system</span> , <span class="disease">adrenal insufficiency</span> , and accumulation of very long chain fatty acids in tissue and body fluids . 