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.
Depending upon location, neural crest cells give rise to most of the peripheral nervous system, as well as various non-neural tissues, like craniofacial bone and cartilage, the thymus and parathyroid glands, and the cardiac outflow tract â in short, all of the tissues that are affected in DiGeorge syndrome.
Using the FISH test for 22q11.2, it was discovered that about 95% of patients with DiGeorge syndrome and VCFS have a deletion. This special FISH test for 22q11.2 deletions is available in many clinical laboratories that look at chromosomes (referred to as cytogenetics laboratories).