23andMe’s 4-star Drug Response reports are structured very similarly to the Carrier Status reports discussed in the previous post, with information about the drug and how our bodies respond to it in the How It Works tab, and details about the genetic variants tested and how they influence drug response in the Technical Report tab, both located near the top of the page under the title of the report. Your results for that report’s drug response are found in a table in the section called “Your Genetic Data.”My 4-star Drug Response reports are ranked in the dashboard according to whether my results for those reports are typical or not. Three reports — Warfarin (Coumadin®) Sensitivity; Clopidogrel (Plavix®) Efficacy; and Alcohol Consumption, Smoking, and Risk of Esophageal Cancer — show atypical results.Warfarin (Coumadin®) Sensitivity Alcohol Flush Reaction trait report). This variant disrupts a protein that normally helps break down toxic byproducts of alcohol, causing the byproduct to build up in the body; people with one copy of the variant have a reduced ability to break down the byproduct, while people with two copies cannot break it down at all. The same toxic byproduct is also found in cigarette smoke. It turns out that people with one or two copies of this genetic variant are at increased risk for esophageal cancer — and the risk is even higher if they are heavy drinkers or smokers. I’ve known for a long time that I flush when I drink alcohol (I have one copy of the disruptive gene variant), and now I’ll be even more mindful to drink only in moderation!
I have typical results for the other 4-star Drug Response reports:
Abacavir Hypersensitivity – Abacavir is a drug used to treat HIV/AIDS but a small percentage of people are hypersensitive to it. This reaction is linked to a specific genetic variant.
Fluorouracil Toxicity – 5-fluorouracil is a chemotherapy drug used to treat several types of cancer. It has very serious side effects in about 30% of people receiving it. Genetic variants in one specific gene are associated with increased risk for 5-fluorouracil toxicity.
Pseudocholinesterase Deficiency – Choline esters are a class of muscle relaxants commonly used in medical procedures, such as general anesthesia. Pseudocholinesterase is a protein that normally breaks down choline ester drugs. Certain variants in the gene for pseudocholinesterase disrupt its activity and cause an individual to experience the drug — and its effects — longer.
Response to Hepatitis C Treatment – The most common treatment for hepatitis C infection has a highly variable success rate. A genetic variant, however, influences your odds of responding favorably to this treatment.
Oral Contraceptives, Hormone Replacement Therapy and Risk of Venous Thromboembolism – Oral estrogen use in women — via oral contraceptives or hormone replacement therapy — has been associated with increased risk for venous thromboembolism (VTE), a potentially serious clotting disorder. Certain genetic variants also significantly increase your risk for VTE, so if you’re a woman taking oral estrogen, it’s important to know these risks as well as your status with regards to these variants. (Risk information for Venous Thromboembolism alone is also available as a Disease Risk report.)
Thiopurine Methyltransferase Deficiency – Thiopurine drugs are chemical compounds used to treat acute lymphoblastic leukemia, autoimmune diseases, and to prevent the rejection of transplanted organs. Thiopurine methyltransferase is a protein that helps convert thiopurines — which are quite toxic — into less harmful forms. Deficiency of this protein can cause an individual to experience serious side effects.The information contained in the 4-star Drug Response reports has the potential to be very useful, but individuals should NOT start, stop, or change any treatment plans unless directed by a medical professional. It’s a good idea, however, to share your drug response reports with your physician so that he or she may make more informed decisions about your care.Next post: Fun with photic sneeze, asparagus anosmia, and the circus of human traits! Check out our companion series, Ancestry at 23andMe, and other articles in 23andMe How-To.