July 13,2000
Genetic Vulnerability to Malaria Discovered
Agence France-Presse

Paris - Many people of African origin have a genetic mutation 
that makes them vulnerable to malaria, especially a severe form 
of the disease that strikes the brain, British scientists 
reported Thursday.     
	The flawed gene, called CD36, controls a protein that may 
inhibit the immune system from reacting against blood cells 
infected with the malaria parasite, they said in the British 
scientific weekly Nature.    
	People who carry the mutated gene are especially 
susceptible to cerebral malaria, which develops when a strain of 
the parasite, Plasmodium falciparum, affects the brain.     
	Cerebral malaria, which can kill within 24 hours, is 
responsible for about half of the two million annual deaths 
caused by malaria. Around 300 million people worldwide are 
affected by the mosquito-borne disease, which is endemic in some 
tropical countries.     
	The survey, among 1,500 people, found that the mutated gene 
is carried by 7.5 percent of black Gambians, 19 percent of black 
Kenyans and 19 percent of Afro-Caribbeans in Britain, one of the 
researchers, Timothy Aitman, told AFP.     
	The rate among Kenyans and British Afro-Caribbeans shows  
an incredibly high frequency,  he said.     
	Previous studies suggest the mutation also exists among 
Koreans, Thais and Japanese, but at a much lower incidence, he 
said.     
	The reason why the gene mutation exists is unclear, he 
said.     
	 Normally, evolution would get rid of the mutation as it 
confers no natural advantage,  Aitman said. One theory is that 
the mutation developed to ward off another disease common in 
Africa or Asia, such as a strain of gut infection, he said.     
	Genes control proteins, the substances that are in charge 
of the body's ability to repair itself and fight off invaders. A 
mutation occurs when there is a flaw in the genetic code that 
causes a gene to malfunction, either by switching off the protein 
or conversely producing excess amounts of it.