MT-TL1 and MELAS: Although point mutations have been identified in each of the 22 mt-tRNAs, MTTL1 – the gene encoding for the mt-tRNALeu(UUR) – is a particularly well-known hotspot for pathogenic point mutations; most notably the m.3243A > G and m.3271T > C mutations which are linked to the mitochondrial encephalomyopathy with lactic acidosis and stroke-like episode (MELAS) syndrome [2–4].