Mitochondrially encoded tRNA histidine, also known as MT-TH, is a transfer RNA which, in humans, is encoded by the mitochondrial MT-TH gene.
MT-TH is a small 69 nucleotide RNA (human mitochondrial map position 12138-12206) that transfers the amino acid histidine to a growing polypeptide at the ribosomal site of protein synthesis during translation.
MT-TH is associated with mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes (MELAS).
It has also been associated with MERRF syndrome.