Deletions

Chromosomal deletions may arise de novo as well as resulting
from unbalanced translocations. De novo deletions may affect
the terminal part of the chromosome or an interstitial
region. Recognisable syndromes have been delineated for the
most commonly occurring deletions. The best known of these
are cri du chat syndrome caused by a terminal deletion of the
short arm of chromosome 5 (5p-) and Wolf–Hirschhorn
syndrome caused by a terminal deletion of the short arm of
chromosome 4