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: By analysis of these compiled mutation data , we demonstrated clustering of WASP mutations within the four most N - terminal exons of the gene and also identified several sites within this region as hotspots for WASP mutation .
### Output Text:
By analysis of these compiled mutation data , we demonstrated clustering of WASP mutations within the four most N - terminal exons of the gene and also identified several sites within this region as hotspots for WASP mutation . 