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: In vitro transfection studies indicated that the inclusion of 120 bp of the 5 UTR in the cDNA construct and the presence of a frameshift mutation at nucleotide 2349 prevented expression of the HD cDNA .
### Output Text:
In vitro transfection studies indicated that the inclusion of 120 bp of the 5 UTR in the cDNA construct and the presence of a frameshift mutation at nucleotide 2349 prevented expression of the <span class="disease">HD</span> cDNA . 