POLG and Alpers syndrome: Recent studies have identified molecular genetic causes of Alpers’ syndrome, including pathogenic mutations in the gene encoding the catalytic subunit of polymerase gamma (POLG), PARS2 which encodes prolyl-tRNA synthetase, FARS2 which encodes phenylalanyl-tRNA synthetase, and NARS2 which encodes asparaginyl-tRNA synthetase, etc, POLG gene variation is the most common (Sofou et al., 2015; Walker et al., 2016; Samanta et al., 2018; Sofou et al., 2021).