HTDG, or Thymine DNA glycosylase, is a human gene encoded by TDG. It may also be known as: G/T mismatch-specific thymine DNA glycosylase; G/T mismatch-specific thymine DNA glycosylase ; Thymine-DNA glycosylase. The encoded protein is an enzyme with an amino acid length of 410 and a mass of 46.1 kDa. HTDG is a member of the TDG/mug DNA glycosylase family. Homologs of this gene exist in other organisms, including: Mouse, Rat, Zebrafish, Frog, Chicken.