Table 2. Defects of mt-tRNA modification.
| Gene | Protein | Clinical presentation | Age of onset | Mode of inheritance | OMIM | References |
|---|---|---|---|---|---|---|
| TRMU | tRNA 5-methylamino-methyl-2- thiouridy-late methyl-transferase |
Reversible infantile liver failure | Infantile | AR | 613070 | Zeharia et al. (2009) [37] Schara et al. (2011) [38] Uusimaa et al. (2011) [39] Gaignard et al. (2013) [40] |
| MTO1 | Mitochondrial translation optimization 1 homolog | Hypertrophic cardiomyopathy and lactic acidosis | Infantile | AR | 614702 | Ghezzi et al. (2012) [41], Baruffini et al. (2013) [42] O’Byrne et al. (2018) [43] |
| GTPBP3 | GTP-binding protein 3 | Hypertrophic or dilated cardiomyopathy, encephalopathy (hypotonia, developmental delay, seizures, visual impairment), lactate↑ | Early childhood | AR | 608536 | Kopajtich et al. (2014) [44] |
| NSUN3 | 5-methylcytosine (m(5)C) methyltransferase | Developmental delay, microcephaly, failure to thrive, lactic acidosis, muscular weakness, external ophthalmoplegia, and nystagmus | Neonatal | AR | 617491 | van Haute et al. (2016) [45] |
| TRMT5 | tRNA methyltransferase 5 | Exercise intolerance, lactic acidosis, growth retardation, developmental delay, complex hereditary spastic paraparesis | Childhood neonatal | AR | 611023 | Powell et al. (2015) [46] Tarnopolsky et al. (2017) [47] |
| TRIT1 | tRNA isopentenyl-transferase | Encephalopathy and myoclonic epilepsy, brain abnormalities | Childhood | AR | Yarham et al. (2014) [48] Kernohan et al. (2017) [49] |
|
| TRNT1 | tRNA nucleotidyltransferase | Retinitis pigmentosa, erythrocitic microcytosis; sideroblastic anemia with B-cell immunodeficiency, periodic fevers, and developmental delay | Neonatal, juvenile | AR | 612907 | Chakraborty et al. (2014) [50] DeLuca et al. (2016) [51] |
| PUS1 | Pseudouridine synthase | Myopathy, lactic acidosis, and sideroblastic anemia (MLASA1) | Early childhood to adult age | AR | 608109 | Bykhovskaya et al. (2004) [52] Fernandez-Vizarra et al. (2007) [53] Metodiev et al. (2015) [54] |
| MTFMT | Methionyl-tRNA formyltransferase | Leigh encephalopathy, white matter lesions, microcephaly, mental retardation, ataxia, and muscular hypotonia | Childhood | AR | 611766 | Tucker et al. (2011) [55] Neeve et al. (2013) [56] Haack et al. (2014) [57] |
OMIM, Online Mendelian Inheritance in Man; AR, autosomal recessive.