Glucose-6-phosphate dehydrogenase (G6PD) deficiency in southern Italy: a study on the population of the Cosenza province.

35,660 healthy children attending secondary school in the Cosenza province, in the North of Calabria (Southern Italy), were screened for G6PD deficiency. Of 16,787 schoolboys, 209 were found to be G6PD deficient (1.24%). Of these, 99 (47.37%) had red cell G6PD activity below 5%, and they were classified as having the G6PD Mediterranean phenotype. The remaining 110 (52.63%), had a mild to moderate degree of deficiency, with an enzyme activity between 5 and 60%. Of these, 82 (74.55%) were electrophoretically normal, while 17 (15.45%) were electrophoretically fast and 11 (10.0%) were electrophoretically slow. The highest incidence of G6PD deficiency is on the Ionian Coast and along the Crati and Esaro river valleys, in good agreement with the distribution of the past malarial endemicity.