We are always in search of small tests which can make our analysis workflow safer. In order to check for sample swaps by accident, we determine the sex of human RNA-Seq samples by default. This helps us to cross-check our result with the sample annotation provided by the client. In case anything suspicious is apparent, we discuss our observation with our clients.
In human samples, the strongest predictor for sex determination is the expression of XIST (X-inactive specific transcript). It is transcribed from the X-Chromosome and it main role is the X-Chromosome inactivation helping to compensate for having two X-Chromosome in women. This process is called “dosage compensation”. More details can be found here. The histogram Xshows the log2 expression values of XIST from over 600 RNA-Seq samples collected by the 1000 Genome Project . A clear cutoff can be set between XIST negative male subjects and female subjects with high XIST expression.
In human samples, the strongest predictor for sex determination is the expression of XIST (X-inactive specific transcript). It is transcribed from the X-Chromosome and it main role is the X-Chromosome inactivation helping to compensate for having two X-Chromosome in women. This process is called “dosage compensation”. More details can be found here. The histogram Xshows the log2 expression values of XIST from over 600 RNA-Seq samples collected by the 1000 Genome Project . A clear cutoff can be set between XIST negative male subjects and female subjects with high XIST expression.
