SSS 2009-12-14

（单词翻译）

Sickle¹ cell disease is a blood disorder² due to a single genetic⁴ mutation⁵. It remains⁶ in populations because the mutation has a flip⁷ side—it helps to protect against malaria⁸. Now another mutation has been shown to afford similar protection. Deficiency in the enzyme⁹ glucose-6-phosphate-dehydrogenase, known as G6PD deficiency, leads to anemia¹⁰ and jaundice. The condition affects more than 400 million people.

Scientists had thought that the prevalence of the deficiency might also be linked to protection against malaria, but they weren’t able to find a connection in Africa. Now a study in Asia shows how the gene³ for G6PD-deficiency can indeed help. It appeared in the December 11th edition of the journal Science. The deficiency is particularly common in Myanmar and Thailand. So researchers spent eight years studying the Karen people in Thailand, who live near the Myanmar border. They showed that the mutation definitely reduces the number of malaria-causing Plasmodium vivax parasites¹¹, lessening¹² the severity of the disease.

This protective effect has kept the genetic condition active in the population. Researchers hope that the good side of the mutation can be exploited to develop new and better ways to fight malaria.

—Cynthia Graber