TPMT3B

TPMT3B is a gene that encodes for the enzyme thymidylate synthase 3B, also known as 5-methyltetrahydrofolate-homocysteine methyltransferase. The enzyme plays a crucial role in the metabolism of folate and the synthesis of thymidylate, a nucleotide required for DNA synthesis and repair.

The TPMT3B gene is located on chromosome 21 and is composed of 12 exons. The enzyme encoded by this gene is primarily responsible for the regeneration of methionine from homocysteine, a process that also involves the transfer of a methyl group to homocysteine. This process is also known as the methionine cycle.

Thymidylate synthase 3B is involved in the metabolism of certain anticancer drugs, particularly 6-mercaptopurine and 6-thioguanine. Variations in the TPMT3B gene have been associated with toxicity and altered efficacy of these medications. Individuals with reduced TPMT3B enzyme activity may be at increased risk of adverse effects, such as bone marrow suppression and liver damage.

The TPMT3B gene has been the subject of numerous studies, particularly in the context of pharmacogenomics. Research has shown that genetic variations in the TPMT3B gene can influence the response to certain medications, providing valuable information for personalized medicine approaches. Further studies are needed to fully elucidate the relationship between TPMT3B and its role in human disease susceptibility and response to treatment.