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: We examined galactosylceramidase ( GALC ) cDNA in four Japanese patients with adult onset globoid cell leukodystrophy ( Krabbe disease ; AO - GLD ) by polymerase chain reaction / single - strand conformation polymorphism ( PCR - SSCP ) analysis , subsequent sequence determination , and restriction enzyme digestion of PCR products , initial symptoms were the onset of slowly progressive spastic paraplegia from the middle of the second decade , and all patients had diminished GALC activity in their leukocytes .
### Output Text:
We examined galactosylceramidase ( GALC ) cDNA in four Japanese patients with <span class="disease">adult onset globoid cell leukodystrophy</span> ( <span class="disease">Krabbe disease</span> ; <span class="disease">AO - GLD</span> ) by polymerase chain reaction / single - strand conformation polymorphism ( PCR - SSCP ) analysis , subsequent sequence determination , and restriction enzyme digestion of PCR products , initial symptoms were the onset of slowly progressive <span class="disease">spastic paraplegia</span> from the middle of the second decade , and all patients had <span class="disease">diminished GALC activity</span> in their leukocytes . 