Brain RNA qRT-PCR analysis and comparison with XCI-AS assay results. (a) cDNA analysis of brain samples. The results obtained by qRT-PCR of frontal cortex RNA samples (% of expression of each allele). The discontinuous line indicates 50% of the expression of each allele (each allele is equally present in the sample). (b) Comparison of XCI and qRT-PCR data from patients P109 and P119 with the c.763C > T mutation. Data are shown as % of activation of each X chromosome (% Active) and % RNA expression measured by qRT-PCR.