TPMT (Thio Purine Methyl Transferase) Genotyping

Thiopurine drugs are offered to patients suffering from health complications such as autoimmune diseases and acute lymphoblastic leukaemia. Doctors might also prescribe these drugs to patients after undergoing organ transplantation.

However, some patients may suffer from the side effects of these drugs as they may be at the risk of developing thiopurine toxicity. The common side effects and ailments patients face after consuming these drugs include:

• Extreme fatigue and weakness 
• Headache 
• Muscular weakness 
• Abnormal weight loss 
• Alopecia 
• Stomatitis 
• Skin infections or rashes 
• Arthralgia

Doctors conduct the thiopurine methyltransferase (TPMT) genotyping test to prevent complications after prescribing thiopurine drugs to patients. It also helps them examine the deficiency of thiopurine methyltransferase among the patients.

Apollo 24|7 provides comprehensive facilities for conducting this TPMT genotyping test. During the process, doctors determine whether the patient's TPMT enzyme level is suitable for administering the thiopurine drugs and if it can metabolise the drugs.

If the patient's TPMT level is too low, the doctors might need to provide alternatives to the thiopurine drugs. The TPMT genotyping test analyses the TPMT enzyme activity and genetic variations in the TPMT gene. The test also identifies genetic differences that might lead to thiopurine toxicity and outlines the patient's probable response to thiopurines.

The TPMT genotyping test can help doctors prevent severe complications like bone marrow suppression and reduced levels of red blood cells, white blood cells, and platelets. Bone marrow damage can result in a condition called myelosuppression, in which the bone marrow is unable to develop red blood cells, platelets, and white blood cells. Conducting the TPMT genotyping test thus helps doctors understand strategies to treat complications like neutropenia and thrombocytopenia.

After the test, the doctors might find that the patient's TPMT enzyme activity is low. In that case, they might reduce the dosage of the thiopurine drugs. Patients might also receive additional drugs to decrease the possible risks of hematopoietic toxicity.

If the patient has very high levels of the TPMT enzyme, the doctor may advise them to take alternative medicine. If the patient has two copies of the TPMT gene, they are more likely to develop myelosuppression. This important genetic information will be identified when the patient undergoes the TPMT genotyping test. The test is also ideal for identifying common variants of TPMT deficiency.