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 is a frequent cause of idiopathic Addison ' s disease in young adult male patients .
### Output Text:
<span class="disease">X - linked adrenoleukodystrophy</span> is a frequent cause of idiopathic <span class="disease">Addison ' s disease</span> in young adult male patients . 