Your genes could hold the answer
HIV
HIV is a virus that attacks your immune system. More specifically it attacks your body’s white blood cells, which are responsible for fighting off diseases. It is a sexually transmitted disease and can also common contracted through the sharing of dirty needles and from mothers during pregnancy (HIV/AIDS). Nowadays many people who have HIV can lead long lives with extensive treatment and management. However, it can still be a terrifying disease with no cure.
What is Delta 32?
Rs333 or CCR5 Delta32 is in the CCR5 gene which helps with many immune-related functions. More specifically it is found in the cell membrane and allows chemokines into the cell. The rs333 allele is a 32-nucleotide deletion located in chromosome 3. This alleles’ main effect is increased resistance to HIV. The allele stops the virus from being able to enter the cell. People who have one copy of this allele are somewhat resistant to the virus and the virus progresses slower. People with 2 copies of the allele are almost completely resistant to the virus. However, having 2 copies of the allele is quite rare. Only about 1% of Caucasians have this variation. It is thought this allele may have evolved in Europeans because it may have also caused resistance to the plague or smallpox. On the other hand, this allele can increase the risk of aneurysms (“rs333”).
Are there other genes that can cause resistance to HIV?
Yes, although Delta 32 is the most famous. Some genes like HLA-B57 and HLA-B27 suppress the virus’s ability to replicate. It is estimated that 3% of the population may have these alleles. Another gene known as DRB1 and DQB1 has been known to stop HIV from progressing to AIDS (PALFIR Genetics). Despite being the most well known and most researched allele linked to fighting HIV there are others that can also help your body fight the virus. Some tests, which are discussed later, that test for the Delta 32 allele will also test for these variations.
How can Delta 32 be used as a treatment?
New treatment for HIV has been built on how this allele functions. By taking medicine that binds with the co-receptor on the cell. The HIV virus is unable to bind with the cell blocking it from entering the cell (PALFIR Genetics). Some scientists have also tried to give bone marrow transplants to patients with HIV from people who are homozygous for the Delta 32 allele (Rothenberger). At this time there seem to be mixed results on the effectiveness of these transplants. Current research indicates that the use of bone marrow transplants used in tandem with other forms of treatment leads to a greater chance of fighting HIV and bringing levels of the disease in the system to below testable levels (Rothenberger).
Another case that has made international news recently is the CRISPER baby scandal. A Chinese doctor named He Jiankui edited the genes of two babies to give them the Delta 32 allele. During his testing, he failed to adhere to multiple safety protocols and has since been fired and is facing criminal investigation (Cohen). Some people have also expressed concern that without fully understanding the effects of this allele we should not be thrusting it onto babies unable to comply.
Should you get tested for Delta 32?
23-and-me tests for the allele but there are other companies like PALFIR Genetics that will also test for just this allele. The delta-32 specific test cost about $200 (PALFIR Genetics). At this point, there does not seem to be a good reason to get tested for this allele, especially for this cost. Since this allele is found mainly in Europeans it may be a waste of money for someone who has no European ancestors (Solloch).
The test may bring someone peace of mind to know they have a resistance to this virus if they have been exposed to it. However, if someone knows they are going to be exposed to the HIV virus there are other medications such as PrEP that can also lower your chances of getting the virus. PrEP is also covered by many insurance companies and can even be purchased for a discounted price if you do not have medical insurance (“Pre-Exposure Prophylaxis (PrEP)”). So instead of spending $200 to find out if you are one of the 1% who is resistant to HIV you ask your doctor about getting a medicine like PrEp instead and save a lot of money and also guarantee the outcome of lower your risk to getting the virus.
If on the other hand, you want to know if you have the allele so you can contribute to research surrounding it such as the bone marrow test or a longitudinal study about the lives of people with the allele then obviously getting tested would be the first step. Another potential problem with getting tested for this allele may be a false sense of security. Although the allele does confer almost immunity to the HIV disease and likely the plague and smallpox this does not mean people should still not be careful. At the end of the day getting tested for a genetic mutation is up to each individual and as fascinating as it sounds that your genes may make you resistant to certain potentially deadly viruses getting tested for these alleles may be more of a hassle than they are worth. I would recommend looking into some gene testing for mutations that could be potentially harmful not one that may be beneficial.
Works Cited
Cohen, Jon, et al. “The Untold Story of the ‘Circle of Trust’ behind the World’s First Gene-Edited Babies.” Science, 2 Aug. 2019, www.sciencemag.org/news/2019/08/untold-story-circle-trust-behind-world-s-first-gene-edited-babies.
“HIV/AIDS | HIV | HIV Symptoms | AIDS.” MedlinePlus, U.S. National Library of Medicine, 27 Nov. 2019, medlineplus.gov/hivaids.html#cat_77.
PALFIR Genetics. “Get Tested Now.” Are You Resistant To HIV?, 2018, www.delta-32.com/ccr5-delta32.html.
“Pre-Exposure Prophylaxis (PrEP).” Centers for Disease Control and Prevention, Centers for Disease Control and Prevention, 8 Nov. 2019, www.cdc.gov/hiv/risk/prep/index.html.
Rothenberger, Meghan, et al. “Transplantation of CCR5∆32 Homozygous Umbilical Cord Blood in a Child With Acute Lymphoblastic Leukemia and Perinatally Acquired HIV Infection.” Open Forum Infectious Diseases, Oxford University Press, 22 May 2018, www.ncbi.nlm.nih.gov/pmc/articles/PMC5965100/.
“rs333.” SNPedia, 3 July 2019, www.snpedia.com/index.php/Rs333.
Solloch, Ute V., et al. “Frequencies of Gene Variant CCR5-Δ32 in 87 Countries Based on next-Generation Sequencing of 1.3 Million Individuals Sampled from 3 National DKMS Donor Centers.” Human Immunology, Elsevier, 5 Oct. 2017, www.sciencedirect.com/science/article/pii/S0198885917305104.
Walker, Nick. “Umbilical Cord Blood Bank to Fight HIV and AIDS.” Umbilical Cord Blood | Parents’ Guide to Cord Blood, 2016, parentsguidecordblood.org/en/news/umbilical-cord-blood-bank-fight-hiv-and-aids.