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: Sequence analysis of the duplicated exons of BRCA1 and 1A1 - 3B and flanking genomic DNA reveals maintenance of the intron - exon structure and a high degree of nucleotide sequence identity , suggesting that these are non - processed pseudogenes and that the duplication is a recent event in evolutionary terms .
### Output Text:
Sequence analysis of the duplicated exons of BRCA1 and 1A1 - 3B and flanking genomic DNA reveals maintenance of the intron - exon structure and a high degree of nucleotide sequence identity , suggesting that these are non - processed pseudogenes and that the duplication is a recent event in evolutionary terms . 