TIMM8A and Mohr-Tranebjaerg syndrome: Mohr-Tranebjaerg syndrome (MTS) is a rare X-linked recessive neurodegenerative disorder caused by mutations in the Translocase of Inner Mitochondrial Membrane 8A (TIMM8A) gene, which encodes TIMM8a, a protein localized to the mitochondrial intermembrane space (IMS).