Detailed ideogram of UPD on chromosome 4. The yellow areas indicate regions of heterozygosity and the blue areas indicate regions of LOH. All regions of LOH were copy neutral: red 5q− syndrome (n = 2); pink RCMDac (n = 1); RA+RCMDnc (n = 5); blue RARS (n = 3); and green RAEB (n = 1).