Exon 8 was targeted with an sgRNA (targeting TCCTGACTTCTCCAGACTTG) and an ssODN template (CCGTCCCCTGTATTCCAACCCACCTCTCAATGGGGCCCGGATCGCAGCAACCATTCTGACGTCTCCGGATTTAGGTAAGCAATGGTAACGATTACTAGCTGTTCCGTGCTACAGCTCCATGAATGGAAAAG) using CRISPR/Cas9 technology to change arginine codon 337 (CGG) to glycine (GGT) (p.R337G, c.1009_1011CGG>GGT). The equivalent human mutation (p.Arg337Gly c.1009C>G) is found in some Malate-Aspartate Shuttle (MAS)-Related Encephalopathy patients.