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: Human orythrocytes that are homozygous for the Duarte enzyme variant of galactosemia ( D / D ) have a characteristic isoform on isoelectric focusing and 50 % reduction in galactose - 1 - phosphate uridyltransferase ( GALT ) enzyme activity .
### Output Text:
Human orythrocytes that are homozygous for the <span class="disease">Duarte enzyme variant of galactosemia</span> ( D / D ) have a characteristic isoform on isoelectric focusing and 50 % reduction in galactose - 1 - phosphate uridyltransferase ( GALT ) enzyme activity . 