46, X,X-X terminal rearrangement/45, X mosaicism in a child with short stature.

A phenotypically female child, investigated because of short stature, had abnormally large, often bipartite Barr bodies and a mosaicism of 45, X cells and cells with 46 chromosomes which included an exceptionally large metacentric chromosome (Xp+). G- and C-banding established that the chromosome was derived from two substantially entire X chromosomes joined short arm-to-short arm, and was likely to be an isodicentric X with functional inactivation of one centromere.