Phased allelic expression on chromosome X.

<p>(A) Allelic ratio of heterozygous SNPs show bimodal distribution of the expressed maternal (magenta dots, n = 37) and paternal (green dots, n = 44) alleles indicated biased expression of the inherited chromosomes. (B) Chromosome-wide allele frequency of the phased alleles from RNAseq indicate that overall, maternal X has a preferential expression in the patient with mean ratio across X of 0.82.7±0.083 (dashed magenta line), compared to paternal alleles of 0.20.3±0.095 (green dashed line). Biased expression in favor of the maternally inherited alleles is preserved across the entire length of the chromosome. However, alleles within genes that potentially escape X inactivation can show bi-allelic expression as defined by an allelic ratio 2SD outside the mean of the phased allele ratios (colored, dotted lines). Essentially all high quality heterozygous SNPs with a minimum of 20X coverage could be phased based on transmission of alleles within the X-linked region. SNPs where transmission of alleles could not be determined (clear circle) lie predominantly in the pseudoautosomal region (PAR1) except two Mendelian errors.