P. F. Wowk

Analysis of HLA-G Polymorphisms in Couples with Implantation Failure

HLA‐G expression is related as an immune modulator of fetal–maternal tolerance, and its levels was correlated with pregnancy outcome. In a case–control study, we investigate the association between the genetic variability of the HLA‐G gene and serum levels of soluble HLA‐G in cases of embryo implantation failure.

HLA class II polymorphisms and recurrent spontaneous abortion in a Southern Brazilian cohort

A high proportion of human recurrent spontaneous abortions (RSA) remain unexplained. The possible association between RSA and different genetic polymorphisms within the human leucocyte antigen system (HLA system, the human major histocompatibility complex) has been investigated with conflicting results since many decades. Here, we describe a case–control study with 136 Southern Brazilian women of predominantly European ancestry (75 control and 61 cases with unexplained RSA). We investigated the relationship between unexplained RSA and alleles and genotypes from two classical loci of the HLA: HLA‐DRB1 and HLA‐DQB1, as well as three loci related to cytokine production and their serum levels: TNFA (−308G>A), IL10 (−1082G>A, −819T>C, −592A>C) and IFNG (+874A>T). Genotyping was performed by an allele‐specific PCR method. While all results concerning cytokine‐related genes turned out to be negative, we found the genotype HLA‐DQB1*02:02, 03:01 to be significantly decreased and the allele HLA‐DRB1*11:04 to be significantly increased among patients.

HLA-E polymorphisms in an Afro-descendant Southern Brazilian population

HLA-E is a non-classical I (Ib) gene which has limited polymorphism and low levels of tissue expression. Currently, 11 alleles are described in the literature with only three protein products. In the present study we investigated HLA-E gene variations at exons 2 and 3 and calculated allele, genotype and haplotype frequencies in a sample of 152 individuals who reported themselves as being Afro-descendants and who are voluntary bone marrow donors living in the state of Paraná, Brazil. The most frequent allele in the sample analyzed was the E(∗)01:01 (59.21%). The presence of the E(∗)01:04 allele was not detected suggesting that it has a very low worldwide frequency or that this allele may be an artifact of sequencing. We reported the most frequent alleles found as well as genotypes and haplotypes and compared our results with the few other studies found in the literature. This study is the first to investigate Afro-descendants from the South of Brazil.

A novel allele, HLA‐A*66:14, identified in a Brazilian volunteer bone marrow donor

The new allele might have arisen from HLA-A*66:01 through a point mutation at codon 182.1 (ACG→GCG) resulting in a non-conservative change from threonine to alanine.

Two novel alleles, HLA-B*40:125 and B*40:129, in the Brazilian population

The new alleles, HLA-B*40:125 and HLA-B*40:129, present a mismatch at codon 103.1 (G → C) and three mismatches at codons 9.1 (C → T), 11.1 (T → G) and 12.1 (G → A).

HLA-DRB1*08:48, a novel allele identified in a Brazilian donor

The new allele presents a point mutation at codon 67.1 (ATC→CTC) resulting in a conservative change from isoleucine to leucine.

Identification of a new HLA‐DRB1*11 variant, HLA‐DRB1*11:130, by sequence‐based typing in a Brazilian individual

HLA-DRB1*11:130, detected in a Euro-Brazilian female, presents a point mutation at codon 59.3 (GAG→GAC).

HLA-B*18:35, a new HLA-B*18 allele identified by sequence-based typing in a Brazilian volunteer bone marrow donor

A novel human leukocyte antigen-B allele named B*18:35 was identified in a Brazilian volunteer bone marrow donor.

A new allele, HLA-B*4212, identified in a Brazilian volunteer bone marrow donors by sequence-based typing.

Here we report the discovery of a novel HLA‐B allele, named B*4212 in a Brazilian volunteer bone marrow donor. The new sequence has nucleotide variation at position 496 (T→G) as compared with B*4201. This variation results in a conservative amino acid substitution from valine to glycine at codon 165 of exon 3.

HLA-G 5' URR SNPs and 3' UTR 14-bp insertion/deletion polymorphism in an Afro-Brazilian population from Paraná State.

The present study investigated 23 SNPs in the 5′URR promoter region and the 14 bp ins/del polymorphism at the 3′UTR region of the HLA‐G gene in 150 individuals with Afro‐Brazilian ancestry. Three haplotypes were found to be the most frequent. Comparing these polymorphisms in other samples, our data suggest that Afro‐Brazilians are more similar to the Euro‐Brazilians than to Hutterite population.