HLA-G 14-bp polymorphism at exon 8 in Amerindian populations from the Brazilian Amazon.
HLA-G (human leukocyte antigen-G) plays an important role in the modulation of the maternal immune system during pregnancy. HLA-G alleles presenting a 14-bp insertion at exon 8 have been associated with decreased messenger RNA levels, preeclampsia, and miscarriages. This suggests that natural selection may exert a strong influence against the insertion allele in isolated populations. DNA samples from 384 Amazonian Indians spread across seven isolated tribes were evaluated for the 14-bp polymorphism. The insertion frequency (38.54%) was somewhat low. The Ewens-Watterson's neutrality test showed a slight trend toward balancing selection operating at this locus but no correlation between the 14-bp locus and fertility data was found. To sum up, no definitive evidence was obtained indicating that the 14-bp frequencies in Amerindians depart from neutrality.
Mendes-Junior
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Division of Clinical Immunology, Department of Medicine, School of Medicine of Ribeirão Preto, University of São Paulo, Brazil. ctmendes@rge.fmrp.usp.br
Castelli
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Simões
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Simões
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Donadi
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D000022:Abortion, Spontaneous / Q000235:genetics; D001938:Brazil; D005091:Exons / Q000235:genetics*; D005260:Female; D005828:Genetics, Population; D006680:HLA Antigens / Q000235:genetics*; D059951:HLA-G Antigens; D015395:Histocompatibility Antigens Class I / Q000235:genetics*; D006801:Humans; D007199:Indians, South American / Q000235:genetics; D008297:Male; D011110:Polymorphism, Genetic; D011225:Pre-Eclampsia / Q000235:genetics; D011247:Pregnancy
D006680:HLA Antigens; D059951:HLA-G Antigens; D015395:Histocompatibility Antigens Class I