Roman Conquerors Destroyed HIV Resistance in Early Europe

From New Scientist:

It appears that the Roman Empire left a legacy that may still affect modern Europe – those living within its conquered lands are more susceptible to HIV. It could explain why a gene that confers resistance to HIV varies in frequency across the continent. The gene in question codes for a protein receptor called CCR5. The HIV virus binds to this receptor before entering cells. One gene variant, called CCR5-Delta32, has 32 DNA base pairs missing and produces a receptor that HIV cannot bind to, which prevents the virus from entering the cells. People with this variant have some resistance to HIV infection and also take longer to develop AIDS. [Did the Romans destroy Europe’s HIV resistance? – health – 03 September 2008]