Heatmap of SNP allele expression pattern in X chromosome. Variant allele frequencies (VAFs) of the SNP genotype from WGS data were plotted on the first left column. VAFs of SNP expressions of 4 samples from RNA-seq data were plotted on the right 4 columns. Despite WGS data that show the presence of heterozygosity (ie, VAF ranges from 25% to 75%) in each SNP loci, RNA-seq data demonstrated the loss of heterozygosity (either 0% or 100%) in the majority of leukemia and germline cells, which exclusively expressed SNP alleles inherited from the patient’s father except FAM104B and the pseudoautosomal region (supplemental Figure 1). This finding is consistent with persistent XCI in hematopoietic lineage cells in the patient. Tx, transplant