Source:http://linkedlifedata.com/resource/umls/id/C1511760
NCI: Absence of a segment of DNA; may be as small as a single base or as large as a whole chromosome.,NCI: Any rearrangement to the genomic content that results in the loss of one or more nucleotides of DNA. Deletions are generally irreversible rearrangements. They may alter the reading frame of a gene, or may result in loss of large chromosomal regions.