Single nucleotide polymorphism array results and initial mutation analysis. (A) Array analysis of 2 control patients showing copy number (CN) and loss of heterozygosity (LOH) outputs. The x-axis for the CN plots show (copy number)⁻² as determined by CNAT, with values approaching or exceeding −1 indicating deletions and greater than +1 indicating amplifications. The x-axis for LOH shows log₁₀P values (ie, 20 indicates 10⁻²⁰). The 2 panels on the left are from a polycythemia vera (PV) case with a homozygous V617F JAK2 mutation. There is no gross copy number change (individual datapoints spread around the zero line), but a large block of homozygous SNP calls at 9p indicative of aUPD. The 2 panels on the right are from a chronic myeloid leukemia (CML) blast crisis case and show LOH accompanied by a 20q deletion. (B) For case UPN 5, a large block of 11q aUPD is apparent on analysis of granulocytes but almost completely absent from mononuclear cells (MNCs) extracted from the same sample. (C) Chromosome 1p aUPD in case UPN 27 is associated with a biallelic G>T MPL mutation that is predicted to result in a W515L substitution. (D) Whole chromosome 13 isodisomy in case UPN 28 associated with a homozygous FLT3 ITD. Two controls are shown: an acute myeloid leukemia (AML) patient previously known to have a heterozygous FLT3 ITD and a healthy individual.