Summary
Most of the population in certain areas of Melanesia have one α-globin gene deletion (α thal2). It is thought that the high frequencies of α thal2 in this population is due to a selective advantage given by malaria infection to carriers of α thal2. We are interested in neighboring Polynesia which, although adjacent to Melanesia, has always been free of malaria due to the absence of the vector anopheles. We studied 60 Polynesian Samoans and 150 Malaysians by restriction endonuclease gene mapping using Eco RI, Bam HI, and Bgl II and hybridization to 32P-labeled α-globin gene probe. Seven among the 60 (11.7%) Samoans had triplicated α-globin loci type 1, while none had α thal2. On digestion with Bgl II the third α-globin gene was found in an additional 3.7kb fragment in all seven Samoans with triplicated α-globin loci, while digestion with Bam HI produced an abnormal elongated 18.2 kb fragment carrying α-globin genes in addition to the normal 14.5 kb fragment. None of the Polynesian Samoans had α thal2 or α thal1. Only two of the Malaysians had triplicated α-globin loci.
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Lie-Injo, L.E., Pawson, I.G. & Solai, A. High frequency of triplicated α-globin loci and absence or low frequency of α thalassemia in Polynesian Samoans. Hum Genet 70, 116–118 (1985). https://doi.org/10.1007/BF00273068
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DOI: https://doi.org/10.1007/BF00273068