Mitochondrial neurogastrointestinal encephalomyopathy (MNGIE) is a fatal and rare autosomal recessive disorder of nucleotide metabolism caused by mutations in the nuclear thymidine phosphorylase gene (TYMP), which encodes cytosolic thymidine phosphorylase, the enzyme required for the normal metabolism of pyrimidine deoxynucleosides, thymidine, and deoxyuridine [1,2]. This evidence concerns the gene TYMP and mitochondrial neurogastrointestinal encephalomyopathy.