Hello I am working with RNA seq data and generated FastQC quality report. In the report while checking section "per base sequence quality" I noticed that box plat for bases (showing upper and lower quartile) present towards the end of the chart but not from the start . Mean square line and median value is present through out the chart but lower and upper quartile is not consistent. Kindly suggest what could be the possible reason.
Fast QC per sequence base quality report