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: Using statistical models specifically designed to study single - sperm segregation data , we find no evidence of meiotic segregation distortion .
### Output Text:
Using statistical models specifically designed to study single - sperm segregation data , we find no evidence of meiotic segregation distortion . 