18p monosomy with midline defects and a de novo satellite identified by FISH.

We report a girl with an 18p deletion and showing a total GH deficiency, a single central maxillary incisor, and a pituitary dysplasia. This suggests that del(18)(p) could be involved in pituitary dysplasia. We review the association between midline developmental defects and chromosome 18 anomalies. This case is due to a de novo satellite resulting from an unbalanced translocation t(18p;13p) identified by FISH. This is the first case of this cytogenetic mechanism in the 18p monosomy.