I can understand that you (the reader of this post) might be ignorant of the science behind HIV and the delta 32 gene configuration. After all, it is kind of complicated and most people are simply not interested in the subject. My following comments are not directed at you.
Quit with your racist bullshit. There is a pretty damn clear explanation why HIV transmission rates are significantly lower amongst Caucasians. The information about this is easily available, so educate yourself about HIV then go find some other "racist outrage" about which to be outraged.
A google search, "delta 32 HIV", yielded 3,620,000 hits. I suggest you progs read the first three, or have a conservative read them to you.
http://www.nature.com/scitable/blog/viruses101/hiv_resistant_mutation
http://www.sciencedaily.com/releases/2005/03/050325234239.htm
http://www.ncbi.nlm.nih.gov/pubmed/15815693
http://en.wikipedia.org/wiki/CCR5
At least one copy of CCR5-Δ32 is found in about 4–16% of people of European descent. It has been speculated that this allele was favored by natural selection during the Black Death for Northern Europeans, but further research has revealed that the gene did not protect against the Black Death.[19] The current hypothesis is of protection vs smallpox throughout Europe,[19] especially in the major trade cities and in isolated islands and archipelagos, such as Iceland and the Azores.[20]
http://genetics.thetech.org/original_news/news13
HIV can only enter certain cells. How does it find the right cells? By special proteins called receptors.
Receptors sit on the outside of cells to receive messages and transmit them into the cell. HIV grabs onto cells that have a receptor called CD4.
Cells with the CD4 receptor are an important part of the body's system for fighting all diseases (our immune system). HIV gradually destroys these cells and cripples the immune system.
It turns out that CD4 isn't enough. Another protein called CCR5 is needed as well. CCR5, called a co-receptor because it works with CD4, is the door that opens to allow HIV to enter the cell.
Many people who are resistant to HIV have a mutation in the CCR5 gene called CCR5-delta32. The CCR5-delta32 mutation results in a smaller protein that isn't on the outside of the cell anymore. Most forms of HIV cannot infect cells if there is no CCR5 on the surface.
People with two copies of the CCR5 delta32 gene (inherited from both parents) are virtually immune to HIV infection. This occurs in about 1% of Caucasian people.
One copy of CCR5-delta32 seems to give some protection against infection, and makes the disease less severe if infection occurs. This is more common, it is found in up to 20% of Caucasians.
Should everyone be tested for this mutation? Not necessarily. It would be dangerous to assume you are completely safe from infection if you have the CCR5-delta32 mutation.
It's not an airtight guarantee of never getting AIDS. Some unusual types of HIV can use other proteins for entering cells. Rarely, there have been people who have two mutant CCR5 genes who have died from AIDS.
Also, CCR5 is not the whole story of immunity to HIV infection. Some resistant people have been found who have two perfectly normal copies of CCR5. So other genes also contribute to slowing down HIV infection, and scientists are busy trying to identify them.
