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: Abnormal myotonic dystrophy protein kinase levels produce only mild myopathy in mice .
### Output Text:
Abnormal <span class="disease">myotonic dystrophy</span> protein kinase levels produce only mild <span class="disease">myopathy</span> in mice . 