They are the same enzyme. See http://www.chem.qmul.ac.uk/iubmb/enzyme/EC2/1/1/67.html
There is another enzyme, EC 2.1.1.9 with a similar name, but it has a broader range of thiol acceptors compared to EC 2.1.1.67 (TPMT). You can check out this kind of information from either the Enzyme Commission web site, or the Expasy or NCBI servers.

nice answer blcr 😯 😯

I’m not sure what the problem is, exactly. The DNA sequence doesn’t have a different name distinct from the name of the expressed protein. For example, if I clone the gene for lysozyme, I can refer to either the DNA sequence or the expressed protein as “lysozyme”, though, I suppose, I would talk about the ‘DNA sequence of lysozyme’ if I had to make a distinction that wasn’t clear from the context. There are, I think, four names for TPMT that different people have used. Any or all of them could be used to refer to the DNA sequence. You could refer to the accessention number of the DNA sequence if you want, but there can be several such numbers for the same sequence. The accessention number only identifies the sequence within a particular database. I don’t know that there’s anything wrong in saying the TPMT gene expresses Thiopurine methyl transferase.