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: This study is the first to show the effect of a modifying gene on the penetrance of an inherited cancer syndrome
### Output Text:
This study is the first to show the effect of a modifying gene on the penetrance of an <span class="disease">inherited cancer syndrome</span> 