Analysis of chromosome 13 in myeloma samples. (A) Tumor sample 25 has monosomy of chromosome 13 without LOH, compared to the matched control. Figure 1 provides a description. (B) Quantitative analysis of short terminal repeats using the Powerplex 16 System shows that tumor sample 25 (bottom panels) has half the amount of both alleles of marker D13S317 (green peaks) on chromosome 13 compared to the matched control (top panels). Analysis of other chromosomes, including chromosome 21 (marker D21S11, blue peaks), showed matching amounts of both alleles. Internal markers are shown as clear peaks. (C) LOH profiles of 30 myeloma samples, clustered according to LOH frequency by dChip, show that female samples with del(13) always have LOH of chromosome X. Top panel, chromosome 13; bottom panel, chromosome X. Regions of LOH are shown in blue and regions of heterozygosity in yellow. Sex of samples indicated at the top of each lane: M indicates male and F, female. Male samples do not show LOH (blue) on chromosome X due to homozygosity occurring naturally.