From ISOGG Wiki
CCR5 is a gene located on chromosome 3. It is responsible for production of a protein that is also called CCR5. It is thought to offer resistance to HIV and AIDS.
One mutational variant of the CCR5 gene consists of a deletion of 32 consecutive base pairs. This mutation, known as CCR5-Delta32, has been found to occur at rates of 5% to 14% in European populations but is very rare in African, Native American and East Asian populations .