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: To investigate whether the presence of rare HRAS1 alleles increases susceptibility to hereditary breast and ovarian cancer , we have typed a panel of 307 female BRCA1 carriers at this locus using a PCR - based technique .
### Output Text:
To investigate whether the presence of rare HRAS1 alleles increases susceptibility to <span class="disease">hereditary breast and ovarian cancer</span> , we have typed a panel of 307 female BRCA1 carriers at this locus using a PCR - based technique . 