This was one of two heterozygous variants, c.457A > G (p.Arg153Gly; in 3DN is Arg117Gly) and c.925G > A (p.Gly309Ser; in 3DN is Gly273Ser) identified in the human FARS2 gene (NM_006567.3) of Patient 1F (Supporting Information Table S1), both were predicted to be deleterious by SIFT and PolyPhen2.3 This baby girl was 5 months old at the time of diagnosis, presenting with poor growth, persistent lactic acidosis with ketosis. The gene discussed is FARS2; the disease is lactic acidosis.