Monosomy 18p refers to a chromosomal disorder resulting from the deletion of all or part of the short arm of chromosome 18. The disease is chromosome 18p deletion syndrome (MONDO_0007800). Also known as: 18p syndrome, 18p-, De Grouchy syndrome, chromosome 18p deletion, deletion 18p syndrome, monosomy 18p, monosomy type 18p, partial deletion of chromosome 18p.