Genotyping of Human parvovirus B19 among Brazilian patients with hemoglobinopathies

Human parvovirus B19 (B19V) infection can be a life-threatening condition among patients with hereditary (chronic) hemolytic anemias. Our objective was to characterize the infection molecularly among patients with sickle cell disease and thalassemia. Forty-seven patients (37 with sickle cell disease, and 10 with beta-thalassemia major) as well as 47 healthy blood donors were examined for B19V infection by anti-B19V IgG enzyme immunoassay, quantitative PCR, which detects all B19V genotypes, and DNA sequencing. B19V viremia was documented in nine patients (19.1%) as two displayed acute infection and the rest had a low titre viremia (mean 3.4 x 10(4) copies/mL). All donors were negative for B19V DNA. Anti-B19V IgG was detected in 55.3% of the patients and 57.4% among the donors. Based on partial NS1 fragments, all patient isolates were classified as genotype 1 and subgenotype 1A. The evolutionary events of the examined partial NS1 gene sequence were associated with a lack of positive selection. The quantification of all B19V genotypes by a single hydrolytic probe is a technically useful method, but it is difficult to establish relationships between B19V sequence characteristics and infection outcome.

Non-classical HLA-E gene variability in Brazilians: a nearly invariable locus surrounded by the most variable genes in the human genome

The non-classical human leukocyte antigen (HLA) class I genes present a very low rate of variation. So far, only 10 HLA-E alleles encoding three proteins have been described, but only two are frequently found in worldwide populations. Because of its historical background, Brazilians are very suitable for population genetic studies. Therefore, 104 bone marrow donors from Brazil were evaluated for HLA-E exons 14. Seven variation sites were found, including two known single nucleotide polymorphisms (SNPs) at positions +424 and +756 and five new SNPs at positions +170 (intron 1), +1294 (intron 3), +1625, +1645 and +1857 (exon 4). Haplotyping analysis did show eight haplotypes, three of them known as E*01:01:01, E*01:03:01 and E*01:03:02:01 and five HLA-E new alleles that carry the new variation sites. The HLA-E*01:01:01 allele was the predominant haplotype (62.50%), followed by E*01:03:02:01 (24.52%). Selective neutrality tests have disclosed an interesting pattern of selective pressures in which balancing selection is probably shaping allele frequency distributions at an SNP at exon 3 (codon 107), sequence diversity at exon 4 and the non-coding regions is facing significant purifying pressure. Even in an admixed population such as the Brazilian one, the HLA-E locus is very conserved, presenting few polymorphic SNPs in the coding region.

A Transcriptomic View of the Proteome Variability of Newborn and Adult Bothrops jararaca Snake Venoms

Background: Snake bite is a neglected public health problem in communities in rural areas of several countries. Bothrops jararaca causes many snake bites in Brazil and previous studies have demonstrated that the pharmacological activities displayed by its venom undergo a significant ontogenetic shift. Similarly, the venom proteome of B. jararaca exhibits a considerable variation upon neonate to adult transition, which is associated with changes in diet from ectothermic prey in early life to endothermic prey in adulthood. Moreover, it has been shown that the Brazilian commercial antibothropic antivenom, which is produced by immunization with adult venom, is less effective in neutralizing newborn venom effects. On the other hand, venom gland transcripts of newborn snakes are poorly known since all transcriptomic studies have been carried out using mRNA from adult specimens. Methods/Principal Findings: Here we analyzed venom gland cDNA libraries of newborn and adult B. jararaca in order to evaluate whether the variability demonstrated for its venom proteome and pharmacological activities was correlated with differences in the structure of toxin transcripts. The analysis revealed that the variability in B. jararaca venom gland transcriptomes is quantitative, as illustrated by the very high content of metalloproteinases in the newborn venom glands. Moreover, the variability is also characterized by the structural diversity of SVMP precursors found in newborn and adult transcriptomes. In the adult transcriptome, however, the content of metalloproteinase precursors considerably diminishes and the number of transcripts of serine proteinases, C-type lectins and bradykinin-potentiating peptides increase. Moreover, the comparison of the content of ESTs encoding toxins in adult male and female venom glands showed some genderrelated differences. Conclusions/Significance: We demonstrate a substantial shift in toxin transcripts upon snake development and a marked decrease in the metalloproteinase P-III/P-I class ratio which are correlated with changes in the venom proteome complexity and pharmacological activities.

Clinical findings in patients with GLI2 mutations - phenotypic variability

Mutations in the human GLI2 gene were first reported in association with defective anterior pituitary formation, panhypopituitarism, and forebrain anomalies represented by typical holoprosencephaly (HPE) and holoprosencephaly-like (HPE-L) phenotypes and postaxial polydactyly. Subsequently, anophthalmia plus orbital anomalies, heminasal aplasia, branchial arch anomalies and polydactyly have also been incorporated into the general phenotype. Here we described six Brazilian patients with phenotypic manifestations that range from isolated cleft lip/palate with polydactyly, branchial arch anomalies to semi-lobar holoprosencephaly. Novel sequence variants were found in the GLI2 gene in patients with marked involvement of the temporomandibular joint (TMJ), a new clinical finding observed with mutations of this gene. Clinical, molecular and genetic aspects are discussed.

A compound heterozygote SLC26A2 mutation resulting in robin sequence, mild limbs shortness, accelerated carpal ossification, and multiple epiphysial dysplasia in two Brazilian sisters. A new intermediate phenotype between diastrophic dysplasia and recessive multiple epiphyseal dysplasia

Mutations in solute carrier family 26 (sulfate transporter), member 2 (SLC26A2) gene result in a spectrum of autosomal recessive chondrodysplasias that range from the mildest recessive form of multiple epiphysial dysplasia (rMED) through the most common diastrophic dysplasia (DTD) to lethal atelosteogenesis type II and achondrogenesis IB. The clinical variability has been ascribed to quantitative effect of mutations of the sulfate transporter activity. Here we describe two Brazilian sisters, born to healthy and non consanguineous parents, with Robin sequence, mild shortening of upper and lower limbs, brachymetacarpalia/tarsalia, additional and accelerated carpal ossification, marked genu valgum, and multiple epiphysial dysplasia. This phenotype was intermediate between DTD and rMED, and both girls have a compound heterozygous mutations for the SLC26A2, a Finnish founder mutation (c.-26?+?2T>C), and R279W. This combination of mutations has been observed in individuals with different phenotypes, including DTD, DTD variant, and rMED. The distinct phenotype of our cases reinforces the hypothesis that other factors may be influencing the phenotype as previously suggested.