Severe red cell glucose-6-phosphate dehydrogenase (G-6-PD) deficiency has been 
found in an 'aboriginal' Finnish family. 2 male and 9 female carriers of the 
variant G-6-PD were studied. The genetic pattern is consistent with x-linked 
recessive inheritance and the defect is associated with drug (primaquine) 
induced haemolysis. This was demonstrated by enzyme deficient red cell 
(51Cr-labelled) survival studies on a normal volunteer recipient. In addition, 
one of the hemizygotes studied had a slight chronic nonspherocytic haemolytic 
disorder. The partially purified enzyme had many of the characteristics of 
G-6-PD Mediterranean. The occurrence of this G-6-PD Mediterranean type variant 
in the Finnish population, which differs greatly from Mediterranean ethnic 
groups, as well as the association of slight chronic haemolysis with severe 
G-6-PD deficiency is discussed.