MT-TI: MT-TI is a tRNA gene that encodes isoleucine transfer RNA (tRNAIle) [PMC8685365]. It is one of the tRNA genes that are affected in at least one position, with 14 mutated positions reported [PMC3080857]. The most represented tRNA gene with reported mutations is mt-Tl1, followed by mt-Tk and MT-TI [PMC3080857]. Homoplasmic variants, including the MT-TI m.4300A>G variant, can exhibit variable penetrance and clinical variability [PMC9905091]. In a specific pedigree, a C to T transition in the MT-TI gene was identified through sequence analysis of the mitochondrial genome in the maternal lineage [PMC8685365]. The m.4295A>G (MT-TI) variant has been associated with maternal hypertension and maternal sensory hearing loss [PMC9395495]. Additionally, a large European collaboration has shown that mitochondrial DNA variants in MT-TI are causative for a Gitelman-like syndrome [PMC9415222]. References: - [PMC3080857]: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3080857/ - [PMC9905091]: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9905091/ - [PMC8685365]: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8685365/ - [PMC9395495]: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9395495/ - [ PMC9415222]: https://www.ncbi.nlm.nih.gov/pmc/articles/ PMC9415222/