Genomic ideogram showing the distribution of LOH in low-risk MDS patients detected using the 250K SNP assay. Chromosome numbers are below each ideogram. (A) Distribution of UPD greater than 2Mb is shown. One hundred twenty-five regions of UPD were detected: red 5q− Syndrome (n = 33 regions); green RA+RCMDnc (n = 46 regions); blue RARS+RCMD-RS (n = 34 regions); pink RCMDac (n = 10 regions); and green RAEB (n = 2 regions). (B,C) Regions of deletions (del) and amplifications (amp) are shown. CN changes detected: red 5q− syndrome (del, n = 1 region); green RA+RCMDnc (del, n = 7 regions; amp, n = 7 regions); blue RARS+RCMD-RS (del, n = 5 regions; amp, n = 1 region); pink RCMDac (del, n = 5 regions; amp, n = 6 regions); and green RAEB (del, n = 1 region; amp, n = 1 region).