FIGURE 5.

Decision tree for assigning cases to a genetic ploidy subgroup using standardized whole chromosome log2 ratios of chromosome 1, 7, and 14. Single‐nucleotide polymorphism (SNP) arrays with standardized log2 ratios for chromosome 1≥0.28 and chromosome 7 <− 0.33 had a 94% probability of being hypodiploid/near triploid (HoTr) cases. Cases with a standardized log2 ratios <0.28 for chromosome 1 and ≥0.37 for chromosome 14 had 94% probability of being high hyperdiploid (HeH). Cases where the log2 ratio was <0.28 for chromosome 1 and <0.27 for chromosome 14, had an 87% probability of the absence of major ploidy shift. Importantly, these three scenarios accounted for 95% of the patients in the dataset. A total of 11 cases called by cytogenetics and/or SNP array as having ploidy shifts were incorrectly assigned by the decision tree: (A) This patient had high hyperdiploidy and t (9;22)/BCR‐ABL1, which is recognized to have a different pattern of chromosomal gains from primary high hyperdiploidy; ³⁶ (B) Although this patient had a low hypodiploid karyotype with − 7, there was unbalanced translocation between the long arms of chromosome 6 and 7; (C) 4/7 cases failed cytogenetics while none of the remaining three cases had a + 14; (D) Karyotypes had been classed as HoTr by cytogenetics but SNP array analysis was inconclusive