It's a disease of the brain that is commonly accompanied by a fever. It can happen after being infected with the malaria virus. It has a mortality rate of about 50%. Symptoms include comas and loss of consciousness :S
As far as I know, anyone with malaria can get it. You may have thought that it is common to Africans and Asians and this would probably be true. This is because of the fact that malaria is still very present in countries including these people, whilst in developed countries such as the USA and the UK, malaria is extinct.
Though this has nothing to do with race, a person with african ethnicity as far as I know would not be more prone to this disease than anyone else in a malaria free or less prevalent country.