Definition is a rhetorical mode that can be used in something smaller or shorter than a full paper. You can use extended definition for several paragraphs only in a paper of much greater length. You also can add to a paper a one-paragraph definition--like a brief encyclopedia definition.
The research group, headed by Dr. Lukas Sommer at the Swiss Federal Institute of Technology, has identified a heretofore unknown role for the TGF cell-to-cell signaling pathway in the pathogenesis of DiGeorge syndrome.
Practice Essentials. DiGeorge syndrome (DGS) is one of a group of phenotypically similar disordersâincluding velocardiofacial syndrome (VCFS, or Shprintzen syndrome) and conotruncal anomaly face (CTAF) syndromeâthat share a microdeletion of the region, known as the DGS critical region, on chromosome 22 at band 22q11.2 (see the image below).