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: The Type II C2 null allele ( C2Q0 ) is linked to two major histocompatibility haplotypes ( MHC ) that differ from the MHC of the more common Type I C2 deficiency .
### Output Text:
The Type II C2 null allele ( C2Q0 ) is linked to two major histocompatibility haplotypes ( MHC ) that differ from the MHC of the more common <span class="disease">Type I C2 deficiency</span> . 