New TAP2 polymorphisms in Africans.
Polymorphisms in genes encoding transporters associated with antigen processing (TAP) have been associated with heterogeneity of disease progression in HIV-1-infected homosexual men. In our recent AIDS-related studies of cohorts from Rwanda and Zambia, four new polymorphic sites in the TAP2 coding region were detected by single-strand conformation polymorphism (SSCP) and confirmed by bi-directional nucleotide sequencing and restriction enzyme digestion. The first, a substitution of Thr (GCC) for Ala (ACC) at codon position 374 in exon 5, was found in about 13% of Rwandans and Zambians (n=213). The remaining 3 new polymorphisms were seen in the 7th exon with changes of 458Thr-ACG to ACA, 466Gly-GGG to GGA, and 467Val-GTT to Ile-ATT, respectively These 3 variants occurred exclusively on the same chromosome and appeared to have arisen together from the 374Thr-bearing allele. Analyses of the relationship between the 374Thr-467Ile segment and the nearby markers in DQB1 and DRB1 suggested the existence of a unique extended haplotype related to these newly identified variants.
Department of Medicine, University of Alabama at Birmingham, 35294, USA. jtang@epi.soph.uab.edu
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J
Tang
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S
Allen
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E
Karita
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Musonda
R A
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Kaslow
D000071450:ATP Binding Cassette Transporter, Subfamily B, Member 3; D018528:ATP-Binding Cassette Transporters / Q000235:genetics*; D044383:Black People / Q000235:genetics*; D005819:Genetic Markers; D005838:Genotype; D006801:Humans; D008285:Major Histocompatibility Complex; D011110:Polymorphism, Genetic; D012432:Rwanda; D015024:Zambia
D000071450:ATP Binding Cassette Transporter, Subfamily B, Member 3; D018528:ATP-Binding Cassette Transporters; D005819:Genetic Markers; C071692:TAP2 protein, human