Furthermore, disease progression and brain atrophy were attenuated in sheep with early-stage or even advanced-stage disease treated with ICV delivery of recombinant self-complementary AAV9 vectors expressing codon-optimized ovine CLN5 (scAAV9/oCLN5) (Mitchell et al., 2018) (Mitchell et al., 2023a, manuscript co-submitted). This evidence concerns the gene CLN5 and Brain atrophy.