Nuclei with and without sSMC(18) derived from lymphocytes. A) Representative interphase nucleus for case 4. In the figure the position of the sSMC is highlighted (arrowhead) and the pseudocolors together with the applied probes are given. Chromosomes 19 are in intermediate to peripheral positions, chromosomes 18 in peripheral and opposite. The sSMC is in central position. B) Representative interphase nucleus of case 6 using probe set for case 4. Chromosomes 19 are in central position and close together. Both chromosomes 18 are in peripheral and opposite. N.B. Animations of the corresponding nuclei are available as additional file - film 4.