Partial karyotypes of nine different cells from patient No. 22 showing centromeric heterochromatin decondensation of chromosome 1, formation of triradial configurations, and movement of 1q. Decondensation of centromeric heterochromatin and apparent separation of 1p and 1q of one chromosome 1 (arrow), normal chromosomes 19 on right (A). Decondensation of two chromosomes 1 (B). Decondensation of chromosomes 1 with chromosome 19p associating in region of decondensation (arrow) (C). Decondensation of 1qh and assocation of 19p13 with decondensed heterochromatin (arrow); note there are now four copies of 1q (D). Decondensation of 1qh and association of 19p13 with 1qh (arrow) and an extra copy of 1q. Note clear triradial of chromosome 1 (E). The translocation of 1q to 19p13 as it is seen in the vast majority of cells (F). The continuing instability of 1q is illustrated by the apparent decondensation of 1q sequences as it is lost from 19p (arrows); note thread-like chromatin. (G and H). The loss of 1q from 19p is shown by only heterochromatin remaining on 19p (arrow) (I). Note small segments of heterochromtin left on the short arm of 19 in cells (G and H).