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: By applying heteroduplex analysis , nonisotopic SSCP , and direct sequencing , we detected germ - line mutations resulting in premature termination codons or disruption of splice signals in 51 ( 72 % ) of the 71 patients .
### Output Text:
By applying heteroduplex analysis , nonisotopic SSCP , and direct sequencing , we detected germ - line mutations resulting in premature termination codons or disruption of splice signals in 51 ( 72 % ) of the 71 patients . 