POLR3A and leukodystrophy: For example, small RNA sequencing (ultra-high-throughput RNA sequencing, which can be used to quantify unmodified pre-tRNAs as well as some other Pol III products) of RNA extracted from the blood of healthy controls and leukodystrophy patients with c.1771-6C > G mutation in POLR3A, revealed a general but mild decrease in levels of tRNA precursors and 7SL RNA together with an increase in levels of 5S, 7SK, RMRP, and RPPH1 RNAs.