title: Low variability at the HLA-E promoter region in the Brazilian population.
abstract: Little information has been reported regarding the regulatory region of the HLA-E gene. Only a proximal segment (300 bp immediately before exon 1) has been described at IMGT/HLA database. We aimed to evaluate the genetic diversity of the promoter region by PCR amplification and DNA sequencing. We observed a pattern of sequencing interruption in the same position in all samples, suggesting the presence of a secondary structure hampering the DNA polymerase sliding during the sequencing process, which was confirmed after bioinformatics analysis. Considering the promoter region evaluated (nucleotide -440 to -1), only three variation sites were found, including one new variation site at position -104, and the concomitant deletions already described at positions -187 and -186. We concluded that the promoter region of the HLA-E gene presents few and rare variable sites in this population sample; however, the double-stranded branch formation hampered the evaluation of the distant promoter by conventional sequencing.
authors.affiliation: Divisão de Imunologia Clínica, Departamento de Clínica Médica, Faculdade de Medicina de Ribeirão Preto (FMRP), Universidade de São Paulo (USP), 14049-900 Ribeirão Preto, SP, Brazil. Electronic address: luciana.veigacastelli@gmail.com.
authors.forename: Luciana Caricati
authors.initials: LC
authors.lastname: Veiga-Castelli
authors.affiliation: Divisão de Imunologia Clínica, Departamento de Clínica Médica, Faculdade de Medicina de Ribeirão Preto (FMRP), Universidade de São Paulo (USP), 14049-900 Ribeirão Preto, SP, Brazil.
authors.forename: João Marcos da Silveira Bulcão
authors.initials: JM
authors.lastname: Bertuol
authors.affiliation: Departamento de Patologia, Faculdade de Medicina de Botucatu, Universidade Estadual Paulista - UNESP, 18618-970 Botucatu, SP, Brazil.
authors.forename: Erick C
authors.initials: EC
authors.lastname: Castelli
authors.affiliation: Divisão de Imunologia Clínica, Departamento de Clínica Médica, Faculdade de Medicina de Ribeirão Preto (FMRP), Universidade de São Paulo (USP), 14049-900 Ribeirão Preto, SP, Brazil.
authors.forename: Eduardo Antonio
authors.initials: EA
authors.lastname: Donadi
mesh_terms: D001483:Base Sequence; D001938:Brazil; D005260:Female; D005838:Genotype; D006239:Haplotypes; D015395:Histocompatibility Antigens Class I / Q000235:genetics*; D006801:Humans; D008297:Male; D008968:Molecular Conformation; D008969:Molecular Sequence Data; D011110:Polymorphism, Genetic; D011401:Promoter Regions, Genetic / Q000235:genetics*; D012045:Regulatory Sequences, Nucleic Acid / Q000235:genetics*; D000097625:HLA-E Antigens
chemical_list: D015395:Histocompatibility Antigens Class I; D000097625:HLA-E Antigens
keywords: Brazilians; HLA-E; Haplotypes; Polymorphism; Promoter