NARS2 and infantile spasms: In addition, Our data showed that patients with pathogenic NON-POLG (NARS2, FARS2, PARS2, CARS2, and GABRB2) variations showed the characteristics of age at onset was earlier, mostly in the early infantile period, with prominent infantile spasms, less liver damage, and microcephaly, most of the survival time after treatment is longer.