19. Pharmacogenetics Flashcards
A 27 year old woman is brought to the hospital for a outpatient surgery, she is given Succinylcholine as a anesthetic. After the surgery the women is still suffering from muscle paralysis long after what is expected. In defect in which gene may be causing the issue in this patient.
A. BCHE gene B. NAT2 gene C. CYP2D6 gene D. TPMT Gene E. EGFR Gene
RFA
ANS. A. BCHE Gene is the gene related to Butyrylcholinesterase which is the enzyme that metabolizes Succinylcholine
B. NAT2- is N-actyltransferase 2 with is important in the metabolism. If defienct it can cause several issues isoniazid (neuropathy/ hepatoxicity) , hydralazine(SLE), procainamide(SLE), sulfamides(Hypersensitivity, hemolytic anemia, SLE)
C.CYP2D6 is a member of the cytochrome P450 family. It metabolizes a large amount of drugs including: antidepressants, antiarrhythmics and analgesics
D. TPMT catalyzes methylation of anticancer thiopurines link 6-MP and azathioprine. Lead to increase risk of myelosuppression
E EGFR gen- Epidermal growth Factor Receptor is overexpressed in non small cell lung cancer ( NSCLC), Gefitinib targets these receptors to inhibit tyrosine kinase to treat NSCLC
A patient has a bacterial infection and is prescribed sulfonamides. They following the medications instructions. The patient returns to the clinic after two weeks complaining of fatigue and lightheadedness. They present with yellowish tint to their skin and Liver and Spleen are found to be enlarged during palpation they also are producing dark urine. The patient is diagnosed with hemolytic anemia. What is the possible cause of this condition?
A. VKORC1 polymorphism B. CYP2C9 polymorphism C. NAT 2 Mutation D. CYP2D6 Mutation E. G6PD Def.
RFA
ANS E G6PD def. -Sulfonamides causes oxidative stress, with out G6PD cells can’t decrease NADPH causing cell toxification and hemolytic anemia
A.VKORC1- Vitamin K epoxide reductase complex 1 is a gene that affect warfarin dose requirements
B.CYP2C9- patient who carry variants need less Warfarin or run risk of hemorrhage
C. NAT2- slow acetylators- high blood drug level
Fast acetylators- low blood drug levels
D. CYP2D6- codeine ultra metabolizer= high does but can overdose with respiratory depression on standard dose, Poor metabolizers codeine- ineffective
