We examined the extent of variation of the 3′ region of the Circumsporozoite gene among
Plasmodium falciparum isolates through amplification of a selected DNA fragment followed
by DNA sequencing. A total of 32 isolates were analyzed, of which 24 were from Amazon
endemic areas in Brazil and 8 from widely separated geographical regions in the world.
Among Brazilian isolates only 2 variants were detected: 19 displayed the same sequence of
strain 7G8 whereas the 4 remaining isolates differed from the 7G8 strain at five nucleotide …