IS THE FLAVIN-DEFICIENT RED-BLOOD-CELL COMMON IN MAREMMA, ITALY, AN IMPORTANT DEFENSE AGAINST MALARIA IN THIS AREA

There is a high prevalence of a familial navin-deficient red blood cel l in Ferrara province in the Po delta in northern Italy, believed to h ave been selected for by malaria which was endemic from the 12th centu ry. In the present study, activities of FAD-dependent red-cell glutath ione reductase (EGR) in the Grosseto area of Maremma on the west coast of Italy where malaria was endemic from 300 B.C. are compared both wi th activities in the Ferrara area and with activities where there was no history of endemic malaria-in the Florence area and in London in pe ople of Anglo-Saxon origin. EGR activities were similar in Grosseto an d Ferrara and were significantly lower than in Florence and London. As previously found in Ferrara, low EGR activity in Grosseto was shown t o be unrelated to low dietary riboflavin intake. These findings in Gro sseto, suggesting selection by malaria, are particularly interesting b ecause, unlike the situation in Ferrara and most other malarial areas, the prevalence of thalassemia and glucose-6-phosphate dehydrogenase d eficiency is very low, and they do not appear to have been selected fo r in Maremma. It is possible that a flavin-deficient red cell, known t o inhibit growth of the malaria parasite, was an important protecting factor in the population of this area over the centuries.