To systematically investigate the potential contributions of lncMtDloop to mitochondrial structure, we administered injections of AAV-PHP.eB carrying allotropic lncMtDloop fused with the 3’UTR of MRPS12 (designated as SYN: AAV-PHP.eB-lncMtDloop-3’UTRMRPS12) via the tail vein of 11-month-old 3xTg-AD mice and their age-matched controls. The gene discussed is MRPS12; the disease is Alzheimer disease.