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: Three mutations , viz . , G270D , L618S , and exon - 6 skipping ( 535 - 573del ) , produced diminished GALC activity as expected .
### Output Text:
Three mutations , viz . , G270D , L618S , and exon - 6 skipping ( 535 - 573del ) , produced <span class="disease">diminished GALC activity</span> as expected . 