Large-scale selection of highly informative microhaplotypes for ancestry inference and population specific informativeness.

Microhaplotypes (MHs) describe physically close genetic markers that are inherited together and are gaining prominence due to their efficiency in forensic, clinical, and population studies. They excel in kinship analysis, DNA mixture detection, and ancestry inference, offering advantages in precision over individual SNPs and STRs. In this study, a pipeline was developed to efficiently select highly informative MHs from large-scale genomic datasets.

Analysis and comparison of the STR genotypes called with HipSTR, STRait Razor and toaSTR by using next generation sequencing data in a Brazilian population sample.

Short tandem repeats (STRs) are particularly difficult to genotype with rapid evolving next-generation sequencing (NGS) technology. Long amplicons containing repetitive sequences result in alignment and genotyping errors. Stutters arising from polymerase slippage often result in reads with additional or missing repeat copies.

Prediction of eye and hair pigmentation phenotypes using the HIrisPlex system in a Brazilian admixed population sample.

Human pigmentation is a complex trait, probably involving more than 100 genes. Predicting phenotypes using SNPs present in those genes is important for forensic purpose. For this, the HIrisPlex tool was developed for eye and hair color prediction, with both models achieving high accuracy among Europeans.

HLA-G Polymorphisms Are Associated with Non-segmental Vitiligo among Brazilians.

(1) Background: Vitiligo is characterized by white patches on the skin caused by loss of melanocyte activity or the absence of these cells. The available treatments minimize the symptoms by retarding the process of skin depigmentation or re-pigmenting the affected regions. New studies are required for a better comprehension of the mechanisms that trigger the disease and for the development of more efficient treatments.

Applicability of the SNPforID 52-plex panel for human identification and ancestry evaluation in a Brazilian population sample by next-generation sequencing.

SNP analysis is of paramount importance in forensic genetics. The development of new technologies in next-generation sequencing allowed processing a large number of markers in various samples simultaneously. Although SNPs are less informative than STRs, they present lower mutation rates and perform better when using degraded samples.

Comprehensive analysis of gene in hereditary hemochromatosis and in diseases associated with acquired iron overload.

Background: Patients with hepatitis C virus (HCV) and hepatocellular carcinoma (HCC) may or not develop iron overload (IO), which is associated with worst prognosis, because can cause serious damage to organs. gene controls the iron uptake from gut, particularly in patients with hereditary hemochromatosis (HH).

Aim: To identify associations between coding region in patients exhibiting hereditary hemochromatosis and in diseases associated with acquired IO.

Copy number variation in the susceptibility to systemic lupus erythematosus.

Systemic lupus erythematosus (SLE) is an autoimmune disease with a strong genetic component and etiology characterized by chronic inflammation and autoantibody production. The purpose of this study was to ascertain copy number variation (CNV) in SLE using a case-control design in an admixed Brazilian population. The whole-genome detection of CNV was performed using Cytoscan HD array in SLE patients and healthy controls.

Extended HLA-G genetic diversity and ancestry composition in a Brazilian admixed population sample: Implications for HLA-G transcriptional control and for case-control association studies.

Human leukocyte antigen-G (HLA-G) is a nonclassical Major Histocompatibility Complex (MHC) molecule with immunomodulatory function and restricted tissue expression. The genetic diversity of HLA-G has been extensively studied in several populations, however, the segment located upstream -1406 has not yet been evaluated. We characterized the nucleotide variation and haplotype structure of an extended distal region (-2635), all exons and the 3'UTR segment of HLA-G by next-generation sequencing (NGS) in a sample of 335 Brazilian individuals.

Haplotypes from the SLC45A2 gene are associated with the presence of freckles and eye, hair and skin pigmentation in Brazil.

The Solute Carrier Family 45, Member 2 (SLC45A2) gene encodes the Membrane-Associated Transporter Protein (MATP), which mediates melanin synthesis by tyrosinase trafficking and proton transportation to melanosomes. At least two SLC45A2 coding SNPs [E272K (rs26722) and L374F (rs16891982)] were reported influencing normal variation of human pigmentation. Here we aimed at evaluating the influence of haplotypes of 12 SNPs within SLC45A2 in the determination of eye, hair and skin pigmentation in a highly admixed population sample and comparing their frequencies with the ones found in data retrieved from the 1000 Genomes Project.

NAT2, XRCC1 and hOGG1 polymorphisms, cigarette smoking, alcohol consumption and risk of upper aerodigestive tract cancer.

Aim: To evaluate associations between polymorphisms of the N-acetyltransferase 2 (NAT2), human 8-oxoguanine glycosylase 1 (hOGG1) and X-ray repair cross-complementing protein 1 (XRCC1) genes and risk of upper aerodigestive tract (UADT) cancer.

Patients And Methods: A case-control study involving 117 cases and 224 controls was undertaken. The NAT2 gene polymorphisms were genotyped by automated sequencing and XRCC1 Arg399Gln and hOGG1 Ser326Cys polymorphisms were determined by Polymerase Chain Reaction followed by Restriction Fragment Length Polymorphism (PCR-RFLP) methods.

European ancestry predominates in neuromyelitis optica and multiple sclerosis patients from Brazil.

Background: Neuromyelitis optica (NMO) is considered relatively more common in non-Whites, whereas multiple sclerosis (MS) presents a high prevalence rate, particularly in Whites from Western countries populations. However, no study has used ancestry informative markers (AIMs) to estimate the genetic ancestry contribution to NMO patients.

Methods: Twelve AIMs were selected based on the large allele frequency differences among European, African, and Amerindian populations, in order to investigate the genetic contribution of each ancestral group in 236 patients with MS and NMO, diagnosed using the McDonald and Wingerchuck criteria, respectively.

Distribution of the CCR5delta32 allele (gene variant CCR5) in Rondônia, Western Amazonian region, Brazil.

Since around 1723, on the occasion of its initial colonization by Europeans, Rondonia has received successive waves of immigrants. This has been further swelled by individuals from northeastern Brazil, who began entering at the beginning of the twentieth century. The ethnic composition varies across the state according to the various sites of settlement of each wave of immigrants.

Mitochondrial DNA variability among eight Tikúna villages: evidence for an intratribal genetic heterogeneity pattern.

To study the genetic structure of the Tikúna tribe, four major Native American mitochondrial DNA (mtDNA) founder haplogroups were analyzed in 187 Amerindians from eight Tikúna villages located in the Brazilian Amazon. The central position of these villages in the continent makes them relevant for attempts to reconstruct population movements in South America. In this geographic region, there is particular concern regarding the genetic structure of the Tikúna tribe, formerly designated "enigmatic" due to its remarkable degree of intratribal homogeneity and the scarcity of private protein variants.

Afro-derived Brazilian populations: male genetic constitution estimated by Y-chromosomes STRs and AluYAP element polymorphisms.

The genetic constitution of Afro-derived Brazilian populations is barely studied. To improve that knowledge, we investigated the AluYAP element and five Y-chromosome STRs (DYS19, DYS390, DYS391, DYS392, and DYS393) to estimate ethnic male contribution in the constitution of four Brazilian quilombos remnants: Mocambo, Rio das Rãs, Kalunga, and Riacho de Sacutiaba. Results indicated significant differences among communities, corroborating historical information about the Brazilian settlement.

Prognostic factors and survival analysis in a sample of oral squamous cell carcinoma patients.

Objectives: The aims of this report were to describe the 5-year overall survival (OS) in a group of oral squamous cell carcinoma (OSCC) patients and to investigate the effects of age, gender, anatomic localization, tumor evolution time, smoking and alcohol intake, nodal status, tumoral recurrences, histologic classification, p53 and p63 immunoexpression, human papillomavirus DNA presence, and treatment on the prognostic outcome.

Study Design: Survival curves were generated using Kaplan-Meier method, and univariate and multivariate analyses were made using the log rank test and Cox regression, respectively.

Results: The 5-year OS was 28.

Genomic ancestry in urban Afro-Brazilians.

Brazil is the result of interethnic crosses of European, African and Amerindian populations. Allelic frequencies for seven STR loci (TH01, TPOx, CSF1PO, vWA, FES/FPS, F13A1 and CD4), obtained from a sample of 70 individuals identified as Afro-Brazilian and 150 as mulatto, are presented here. Based on the frequencies of these genetic markers, estimates of interethnic admixture showed 62%, 26% and 12% of European, African and Amerindian contribution, respectively, for the mulatto sample and 37% and 63% of European and African contribution, respectively, for the Afro-Brazilian sample.

HPV infection in Brazilian oral squamous cell carcinomapatients and its correlation with clinicopathological outcomes.

This study aims to investigate human papilloma virus (HPV) frequency in Brazilian patients with oral squamous cell carcinoma (OSCC) in order to establish a clinicopathological profile. It will also examine the correlation between patient survival and HPV expression in primary tumors (PTs), and their matched samples (MSs) of recidives, lymph nodal metastasis (LNM) or necropsies. Eighty-seven PTs and their corresponding 87 MSs were tested for HPV infection by polymerase chain reaction (PCR) using general and type-specific HPV primers.

Ancestry informative markers in Amerindians from Brazilian Amazon.

Ancestry informative markers (AIMs) are genetic loci with large frequency differences between the major ethnic groups and are very useful in admixture estimation. However, their frequencies are poorly known within South American indigenous populations, making it difficult to use them in admixture studies with Latin American populations, such as the trihybrid Brazilian population. To minimize this problem, the frequencies of the AIMs FY-null, RB2300, LPL, AT3-I/D, Sb19.

Genomic ancestry of a sample population from the state of São Paulo, Brazil.

Allelic frequencies of eight autosomal short-tandem repeat (STR) loci (TH01, TPOx, CSF1PO, vWA, FES/FPS, F13A1, F13B, and CD4) were determined in 400 individuals born in the State of São Paulo. No significant deviations from Hardy-Weinberg equilibrium were found in any loci analyzed. The Unweighted Pair-Group Method with Arithmetic Mean (UPGMA) tree constructed based on genetic distances revealed that the present population was grouped with Europeans, and separated from African and Amerindian populations.

Allele frequencies and genetic diversity in two groups of wild tufted capuchin monkeys (Cebus apella nigritus) living in an urban forest fragment.

There have been numerous studies genetically characterizing Old World Primates using microsatellites. However, few studies have been made of New World species and none on free-ranging Cebus apella, even though it is probably the most widely distributed species of monkey in the New World. The paucity of studies is due, in part, to the lack of polymorphisms described for this species.

[Myotonic dystrophy type 1 in cataract patients: molecular diagnosis for screening and genetic counseling].

Purpose: To detect MD1 premutation and full mutation carriers among cataract patients and offer familial genetic counseling.

Methods: We studied the DNA of 60 selected cataract patients through polymerase chain reaction analysis. This study was performed at the "Hospital das Clínicas da Faculdade de Medicina de Ribeirão Preto" where selected patients had been examined at the Cataract Outpatient Clinic from 01/01/1982 to 30/06/1995.