Question
Where can I get a genetic test for delta 32 gene?
26 March 2010. Related: All topics.
Hi, I have been reading about delta 32 gene mutation and I want to know if I can be tested for this on the NHS. If not do you know where I can get a test and how much it will cost? Thank you.
Answer
Thank you for your question.
Genetic testing for the delta 32 mutation is not available on the NHS. It would only be available as part of a research programme and I am not aware of research studies in the UK at the moment.
The delta 32 gene mutation is a deletion of part of the genetic sequence making up the CCR5 receptor which is found on the surface of the CD4 cell. HIV uses this receptor to connect with and infect a CD4 cell.
We all have two genes for each characteristic (two sets of chromosomes), one from the mother and one from the father. Having one mutated gene for delta 32 and one regular gene (called heterozygous) is related to a reduced risk from HIV compared to someone with two regular genes. This type of heterozygous mutation occurs in about 20% of Caucasians but in about 1% of people from African origin.
If both genes carry the delta 32 mutation this is called homozygous and occurs in only about 1% of causations. This provides a much stronger protection against HIV. However, this protection is only against a type of HIV that uses the CCR5 co-receptor (called R5 tropic).
Approximately 10% of infections are related to a type of HIV that uses CXCR4 (called X4 tropic) and the delta 32 mutation provide no protection here. The chance someone has X4 tropic HIV increase with the time they have been HIV positive.
Therefore people who are homozygous for delta 32 can still become infected with HIV.
For further information explaining the effect of this mutation please follow this link.
Please see this more recent question that discusses why this test in not very helpful in terms of protection from HIV.
Hi Bk,
Sorry but Charlotte is talking about testing for delta 32 gene. It’s a genetic variation that we get from both parents. So it can’t be given to children.
Good news, Let there be bulk production of CCR5 Delta 32 since majority of us lack it and be given to very child after birth to save the world.
Hi Jaji,
There can be many reasons. Please see here for risk for transmission.
I have been tested several times in my life but have never been positive and i havent been sick but have had sex with a lot of hiv positive people . what could be the reason . do i have any special protection in my genes i wonder . though i am not proud of that
Hi Christine,
This Q&A discusses why i-Base doesn’t link to commercial testing sites. However, recently there have been intersting papers on elite controllers. Please see this link to a recent article in HTB. Perhaps you could ask at your clinic if there are any studies you could enrol on.
I’ve been positive for 24 years and I have never had a viral load and my T cells have always stayed above 856 and I’m considered an elite controller. I’m very interested in having the test done ccr5 delta 32
i-Base doesn’t post link to commercial testing sites.
For a discussion of why we don’t do this, and for links to research about why testing is not a reliable way to protect against HIV, see this more recent question.
http://i-base.info/qa/603
Hey thanks Alex. I checked out a commercial website and I got my kit. Looks good, cant wait for the results to see if I got the genes. Thanks for the website.
I was curious and I tried this last month and I got a package mailed to me after a few days. After I sent the package back, took them about a week to get back to me with the result. Unfortunately I did not have the genetic mutation but it was worth the try lol. The thing I like about them is that ccr5 delta 32 test is the main test they do, so thats why I chose them.
There are several services which will test for this gene and many others for a total price of about US $200.
An individual registers online for the service which includes the testing and then online access to the service results for at least a year. They then send a test kit to the individual. The individual provides one saliva sample into the test kit and ships/mails the kit back. The company then tests the sample and advises the individual when the results are available privately for the individual to access online. This is great news as previously such testing has not been regularly, commercially available. Delta 32 is just one of the hundreds of genes that will be tested for and results rendered.