INTRODUCTION:Significant progress has been made in understanding and treating lung cancer. In the unique context of the Amazonian indigenous population, it is crucial to identify genetic variants in genes important for the risk of developing this cancer. There is a limitation of research on the broader genomic profile of indigenous peoples, especially in the Amazon region, in relation to lung cancer. METHODS:We evaluated the genomic profile of seven genes (KRAS, MET, RET, ERBB2, BRAF, PDL2 and PD-L1) related to lung cancer by sequencing the exome of 64 indigenous individuals belonging to 12 ethines from the Brazilian Amazon. RESULTS:Our study identified six variants of moderate impact already described in the literature, located in the RET, ERBB2, PDL2 and PD-L1 genes. We discovered six new variants unique to the Amazonian Amerindian population, one located in the KRAS gene, two located in the ERBB2 gene, and three located in the PDL2 gene. CONCLUSIONS:The variants studied can potentially exert a significant influence on the heredity and carcinogenesis of lung cancer.

INTRODUCTION:Taxanes are drugs commonly used in the treatment of breast cancer. Despite their proven therapeutic efficacy, they can induce severe toxicities, which can be investigated by pharmacogenomics. In this context, the aim of this study was to investigate 26 molecular biomarkers in 17 pharmacogenes (CYP2C8, ABCB1, CYP1A1, CYP1B1, CYP19A1, CYP3A5, ERCC1, ERBB2, VEGFA, ERCC2, MDM2, MTHFR, RAD51, SOD2, TP53, TANC1 and XRCC1), in women with Breast Cancer undergoing Taxane treatment in the Brazilian Amazon region. METHODS:This study was carried out with 279 women diagnosed with BC, undergoing antineoplastic chemotherapy treatment based on Taxanes (Docetaxel and Paclitaxel), in Brazilian Amazon region. 26 pharmacogenetic markers located in 17 genes involved in the metabolic pathway of Taxanes and related toxicities were selected. Single nucleotide variants were genotyped by allelic discrimination using TaqMan OpenArray Genotyping technology. RESULTS:The study population showed significant associations of Taxane toxicities with ten variants of nine genes: CYP1A1, CYP19A1, CYP3A5, ERCC1, VEGFA, ERCC2, MTHFR, TANC1 and XRCC1. Notably, variants in TANC1 and XRCC1, previously associated with radiotoxicity, were also implicated in Taxane-induced toxicities. The study demonstrated that novel biomarkers may be important for investigating Taxane-induced toxicities in breast cancer. CONCLUSIONS:These findings represent a unique contribution to the field, potentially enabling more precise chemotherapy selection, particularly for populations such as Amazonian women.

BACKGROUND:Acute Lymphoblastic Leukemia (ALL) is a neoplasm of the hematopoietic system characterized by a clonal expansion of abnormal lymphocyte precursor cells. ALL is the most common form of cancer in children, but despite advances in treatment, it can still be fatal. Ethnic differences influence survival rates, and genomic ancestry plays an important role, especially in mixed-race populations such as Latin America. This study aims to analyze the influence of genomic ancestry on toxicity in children with ALL in the Amazon region.METHODS:The study included 171 patients (protocol number 119,649/2012-Ethics Committee) with ALL treated at a pediatric treatment center in Belém do Pará, in the Brazilian Amazon. The patients were submitted to the BFM protocol of induction therapy for ALL. Toxicity was assessed based on laboratory tests and adverse events, classified according to the CTC-NCI guide. Genomic ancestry was determined using autosomal informative markers.RESULTS:The majority of children (94.74%) developed some type of toxicity during treatment, 87.04% of which were severe. Infectious toxicity was the most common, present in 84.8% of cases, 77.24% of which were severe. Amerindian ancestry showed an association with the risk of severe general toxicity and severe infectious toxicity, with a contribution of 35.0% demonstrating a significant increase in risk. In addition, post-induction refractoriness and relapse were also associated with an increased risk of death.CONCLUSION:This study highlights the influence of Amerindian genomic ancestry on response to therapy and toxicity in children with ALL in the Amazon region. Understanding these associations can contribute to personalizing treatment and improving clinical outcomes.

Coronavirus disease 2019 (COVID-19) is an infection caused by SARS-CoV-2. Genome-wide association studies (GWASs) have suggested a strong association of genetic factors with the severity of the disease. However, many of these studies have been completed in European populations, and little is known about the genetic variability of indigenous peoples’ underlying infection by SARS-CoV-2. The objective of the study is to investigate genetic variants present in the genes AQP3, ARHGAP27, ELF5L, IFNAR2, LIMD1, OAS1 and UPK1A, selected due to their association with the severity of COVID-19, in a sample of indigenous people from the Brazilian Amazon in order to describe potential new and already studied variants. We performed the complete sequencing of the exome of 64 healthy indigenous people from the Brazilian Amazon. The allele frequency data of the population were compared with data from other continental populations. A total of 66 variants present in the seven genes studied were identified, including a variant with a high impact on the ARHGAP27 gene (rs201721078) and three new variants located in the Amazon Indigenous populations (INDG) present in the AQP3, IFNAR2 and LIMD1 genes, with low, moderate and modifier impact, respectively.

Studies have identified elevated levels of mercury in Amazonian Indigenous individuals, highlighting them as one of the most exposed to risks. In the unique context of the Brazilian Indigenous population, it is crucial to identify genetic variants with clinical significance to better understand vulnerability to mercury and its adverse effects. Currently, there is a lack of research on the broader genomic profile of Indigenous people, particularly those from the Amazon region, concerning mercury contamination. Therefore, the aim of this study was to assess the genomic profile related to the processes of mercury absorption, distribution, metabolism, and excretion in 64 Indigenous individuals from the Brazilian Amazon. We aimed to determine whether these individuals exhibit a higher susceptibility to mercury exposure. Our study identified three high-impact variants (GSTA1 rs1051775, GSTM1 rs1183423000, and rs1241704212), with the latter two showing a higher frequency in the study population compared to global populations. Additionally, we discovered seven new variants with modifier impact and a genomic profile different from the worldwide populations. These genetic variants may predispose the study population to more harmful mercury exposure compared to global populations. As the first study to analyze broader genomics of mercury metabolism pathways in Brazilian Amazonian Amerindians, we emphasize that our research aims to contribute to public policies by utilizing genomic investigation as a method to identify populations with a heightened susceptibility to mercury exposure.

Acute lymphoblastic leukemia (ALL) is the most common childhood cancer in the world. Single nucleotide variants (SNVs) in miRNA and genes encoding proteins of the miRNA synthesis complex (SC) may affect the processing of drugs used in the treatment of ALL, resulting in treatment-related toxicities (TRTs). We investigated the role of 25 SNVs in microRNA genes and genes encoding proteins of the miRNA SC, in 77 patients treated for ALL-B from the Brazilian Amazon. The 25 SNVs were investigated using the TaqMan® OpenArray™ Genotyping System. SNVs rs2292832 (MIR149), rs2043556 (MIR605), and rs10505168 (MIR2053) were associated with an increased risk of developing Neurological Toxicity, while rs2505901 (MIR938) was associated with protection from this toxicity. MIR2053 (rs10505168) and MIR323B (rs56103835) were associated with protection from gastrointestinal toxicity, while DROSHA (rs639174) increased the risk of development. The rs2043556 (MIR605) variant was related to protection from infectious toxicity. SNVs rs12904 (MIR200C), rs3746444 (MIR499A), and rs10739971 (MIRLET7A1) were associated with a lower risk for severe hematologic toxicity during ALL treatment. These findings reveal the potential for the use of these genetic variants to understand the development of toxicities related to the treatment of ALL in patients from the Brazilian Amazon region.

Breast cancer is the most common malignant disease and the leading cause of mortality among women worldwide. Antineoplastic chemotherapy is one of its primary treatments, typically based on the class of drugs known as taxanes. Despite their proven therapeutic efficacy, these drugs can induce severe toxicities, leading to dose limitations or even treatment discontinuation. The objective of this study was to describe the clinical-epidemiological profile, risk factors, and toxicities of taxane-based chemotherapy treatment in women with breast cancer in the Amazon region. This is a cross-sectional, quantitative, and descriptive study conducted with 300 women diagnosed with breast cancer undergoing taxane treatment. Most patients were in the 40-49 age range, of brown ethnicity, and had completed elementary school. The majority of patients had risk factors such as alcoholism and a sedentary lifestyles. Most women had their first pregnancy between the ages of 18 and 21, breastfed their children, had menarche between the ages of 12 and 13, and were pre-menopausal and with a family history of cancer. The most frequent histological type was non-special invasive carcinoma and the Luminal B subtype. Most participants in this study showed taxane toxicity, with neurotoxicity being the most frequent. These findings reveal the importance of early detection, comprehensive risk factors, and effective management of treatment toxicities to improve patient outcomes in breast cancer care in the Amazon region.

Gastric cancer (GC) is a multifactorial, complex, and aggressive disease with a prevalence of one million new cases and high global mortality. Factors such as genetic, epigenetic, and environmental changes contribute to the onset and progression of the disease. Identification of INDELs in miRNA and its target sites in current studies showed an important role in the development of cancer. In GC, miRNAs act as oncogenes or tumor suppressors, favoring important cancer pathways, such as cell proliferation and migration. This work aims to investigate INDELs in the coding region of miRNAs (hsa-miR-302c, hsa-miR-548AJ-2, hsa-miR-4274, hsa-miR-630, hsa-miR-516B-2, hsa-miR-4463, hsa-miR-3945, hsa-miR-548H_4, hsa-miR-920, has-mir-3171, and hsa-miR-3652) that may be associated with susceptibility and clinical variants of gastric cancer. For this study, 301 patients with GC and 145 individuals from the control group were selected from an admixed population in the Brazilian Amazon. The results showed the hsa-miR-4463, hsa-miR-3945, hsa-miR-548H_4, hsa-miR-920 and hsa-miR-3652 variants were associated with gastric cancer susceptibility. The hsa-miR-4463 was significantly associated with clinical features of GC such as diffuse gastric tumor histological type, "non-cardia" localization region, and early onset. Our findings indicated that INDELs could be potentially functional genetic variants for gastric cancer risk.

Non-small cell lung cancer (NSCLC) accounts for the vast majority of cases of lung neoplasms. It is formed in multiple stages, with interactions between environmental risk factors and individual genetic susceptibility and with genes involved in the immune and inflammatory response paths, cell or genome stability, and metabolism, among others. Our objective was to evaluate the association between five genetic variants (IL-1A, NFKB1, PAR1, TP53, and UCP2) and the development of NSCLC in the Brazilian Amazon. The study included 263 individuals with and without lung cancer. The samples were analyzed for the genetic variants of NFKB1 (rs28362491), PAR1 (rs11267092), TP53 (rs17878362), IL-1A (rs3783553), and UCP2 (INDEL 45-bp), which were genotyped in PCR, followed by an analysis of the fragments, in which we applied a previously developed set of informative ancestral markers. We used a logistic regression model to identify differences in the allele and the genotypic frequencies among individuals and their association with NSCLC. The variables of gender, age, and smoking were controlled in the multivariate analysis to prevent confusion by association. The individuals that were homozygous for the Del/Del of polymorphism NFKB1 (rs28362491) (p = 0.018; OR = 0.332) demonstrate a significant association with NSCLC, which was similar to that observed in the variants of PAR1 (rs11267092) (p = 0.023; OR = 0.471) and TP53 (rs17878362) (p = 0.041; OR = 0.510). Moreover, the individuals with the Ins/Ins genotype of polymorphism IL-1A (rs3783553) demonstrated greater risk for NSCLC (p = 0.033; OR = 2.002), as did the volunteers with the Del/Del of UCP2 (INDEL 45-bp) (p = 0.031; OR = 2.031). The five polymorphisms investigated can contribute towards NSCLC susceptibility in the population of the Brazilian Amazon.

Autism spectrum disorder is a neurodevelopmental disorder, affecting one in 160 children worldwide. The causes of autism are still poorly understood, but research shows the relevance of genetic factors in its pathophysiology, including the CHD8, SCN2A, FOXP1 and SYNGAP1 genes. Information about the genetic influence on various diseases, including autism, in the Amerindian population from Amazon, is still scarce. We investigated 35 variants of the CHD8, SCN2A, FOXP1, and SYNGAP1 gene in Amazonian Amerindians in comparison with publicly available population frequencies from the 1000 Genomes Project database. Our study identified 16 variants in the Amerindian population of the Amazon with frequencies significantly different from the other populations. Among them, the SCN2A (rs17183814, rs75109281, and rs150453735), FOXP1 (rs56850311 and rs939845), and SYNGAP1 (rs9394145 and rs115441992) variants presented higher frequency than all other populations analyzed. In addition, nine variants were found with lower frequency among the Amerindians: CHD8 (rs35057134 and rs10467770), SCN2A (rs3769951, rs2304014, rs1838846, and rs7593568), FOXP1 (rs112773801 and rs56850311), and SYNGAP1 (rs453590). These data show the unique genetic profile of the indigenous population of the Brazilian Amazon. Knowledge of these variants can help to understand the pathophysiology and diagnosis of autism among Amerindians, Brazilians, and in admixed populations that have contributions from this ethnic group.

The mucin (MUC) family includes several genes aberrantly expressed in multiple carcinomas and mediates diverse pathways essentials for oncogenesis, in both solid and hematological malignancies. Acute Lymphoblastic Leukemia (ALL) can have its course influenced by genetic variants, and it seems more frequent in the Amerindian population, which has been understudied. Therefore, the present work aimed to investigate the MUC family exome in Amerindian individuals from the Brazilian Amazon, in a sample containing healthy Native Americans (NAMs) and indigenous subjects with ALL, comparing the frequency of polymorphisms between these two groups. The population was composed of 64 Amerindians from the Brazilian Amazon, from 12 different isolated tribes, five of whom were diagnosed with ALL. We analyzed 16 genes from the MUC family and found a total of 1858 variants. We compared the frequency of each variant in the ALL vs. NAM group, which led to 77 variants with a significant difference and, among these, we excluded those with a low impact, resulting in 63 variants, which were distributed in nine genes, concentrated especially in MUC 19 (n = 30) and MUC 3A (n = 18). Finally, 11 new variants were found in the NAM population. This is the first work with a sample of native Americans with cancer, a population which is susceptible to ALL, but remains understudied. The MUC family seems to have an influence on the development of ALL in the Amerindian population and especially MUC19 and MUC3A are shown as possible hotspots. In addition, the 11 new variants found point to the need to have their clinical impact analyzed.

In Brazil, Acute lymphoid leukemia (ALL) is the leading cause of cancer deaths in children and adolescents. Treatment toxicity is one of the reasons for stopping chemotherapy. Amerindian genomic ancestry is an important factor for this event due to fluctuations in frequencies of genetic variants, as in the NUDT15 and SLC22A1 genes, which make up the pharmacokinetic and pharmacodynamic pathways of chemotherapy. This study aimed to investigate possible associations between NUDT15 (rs1272632214) and SLC22A1 (rs202220802) gene polymorphism and genomic ancestry as a risk of treatment toxicities in patients with childhood ALL in the Amazon region of Brazil. The studied population consisted of 51 patients with a recent diagnosis of ALL when experiencing induction therapy relative to the BFM 2009 protocol. Our results evidenced a significant association of risk of severe infectious toxicity for the variant of the SLC22A1 gene (OR: 3.18, p = 0.031). Genetic ancestry analyses demonstrated that patients who had a high contribution of African ancestry had a significant protective effect for the development of toxicity (OR: 0.174; p = 0.010), possibly due to risk effects of the Amerindian contribution. Our results indicate that mixed populations with a high degree of African ancestry have a lower risk of developing general toxicity during induction therapy for ALL. In addition, individuals with the SLC22A1 variant have a higher risk of developing severe infectious toxicity while undergoing the same therapy.

Objective: Identify the global functionality of hospitalized elderly, correlating the performance to basic (BADL) and instrumental (IADL) activities of daily life, with the main functional systems (cognition, mood, mobility and communication). Methods: Analytical, observational, cross-sectional study, with the participation of 94 elderly patients admitted to a medical clinic. The tools used in the assessments were: the Katz Scale, Lawton and Brody Scale, Mini-Mental State Examination (MMSE), Geriatric Depression Scale 15 (GDS-15), Timed Up and Go Test (TUG) and the Functional Assessment of Communication Skills from the American Speech-Language-Hearing Association (ASHA FACS). Results: 94 elderly people were evaluated, where most had some degree of dependence for BADL (61.71%) and IADL (52.13%). In functional systems, autonomy proved to be preserved with an average performance of 18.14 points on the MMSE, and 4.43 points in the GDS-15; independence was altered, for average performance of 21.82 seconds on the TUG, classifying them with regular mobility, and 5.27 points in ASHA FACS, considering them as in need of moderate assistance in this task. It was evidenced moderate and significant association between performance for IADL and BADL in nearly all functional systems. Conclusion: The study population presented changed overall functionality, due to some degree of dependence in BADL and IADL, with preserved autonomy and impaired independence. The correlations showed that with the decline of the major functional systems occurred decline in overall functionality.

e15532 Background: Fluoropyrimidine-based treatments are still considered challenging due to the wide variability in efficacy and toxicity rates presented by patients. This variability can be explained, partially, by individual genetic differences that contribute significantly to the response of the drug, with 30% of patients experiencing severe toxicity related to dihydropyrimidine dehydrogenase (DPD) deficiency and 5-Fluorouracil (5-FU) metabolism. Methods: This study analyzed the exome of the main genes involved in the fluoropyrimidine metabolism pathway ( DPYD, TYMS / ENOSF1, MTHFR, CDA, CES2, and UGT1A1) in seven patient who developed fatal 5-FU toxicity diagnosed with gastric or colorectal adenocarcinoma and underwent fluoropyrimidine-based cancer treatment. The genotyping service was carried out at CEGEN-PRB3-ISCIII; it is supported by grant PT17/0019, of the PE I+D+i 2013-2016, funded by ISCIII and ERDF. Results: A total of 74 genetic polymorphisms were identified, 25 of which stand out due to their potential role in the safety of 5-FU administration. Eight variants are exclusive of the studied population (two found in the DPYD gene, two in the MHFR, one in the CES2, and three in the UGT1A1 gene) and 17 have already been associated with fluoropyrimidine efficacy and/or toxicity events: 10 of them are located in the DPYD gene (rs1801159, rs2297595, rs72728438, rs17376848, rs1801160, rs1801265, rs22447512, rs5568, rs56038477, rs56276561, and rs56293913), two in the intergenic region of the TYMS/ ENOSF1 genes (rs11280056 and rs699517), two in the MTHFR gene (rs1801131 and rs1801133) and three in the CDA gene (rs1048977, rs2072671, and rs3215400). Conclusions: The current study has allowed us to obtain a global profile of genetic variants in the pharmacokinetic and pharmacodynamic pathways of fluoropyrimidines in patients with high genetic miscegenation in the northern region of Brazil who have evolved to death due to the fatal toxicity resulting from 5-FU-based therapies. Keywords: Pharmacogenomics; Exome; 5-Fluorouracil; Drug toxicity; Brazil.

e19025 Background: The MUC family includes several genes previously associated with carcinogenesis and it is associated with solid neoplasms such as those of the gastrointestinal tract. As far as we are aware, there are no studies relating MUC genes to acute lymphoblastic leukemia (ALL), and this type of cancer is more frequent in the Amerindian population, which has been understudied. Therefore, the present work aimed to investigate the MUC family exome in Amerindian individuals from Brazilian Amazon, in a sample containing healthy Native Americans (NAM) and indigenous with ALL, comparing the frequency of polymorphisms between these two groups. Methods: The population was formed by 64 Amerindians from the Brazilian Amazon from 12 different ethnic groups, 5 of whom were diagnosed with ALL. We analyzed 16 genes from the MUC family (MUC1, MUC2, MUC3A, MUC4, MUC5AC, MUC5B, MUC6, MUC7, MUC12, MUC13, MUC15, MUC16, MUC17, MUC19, MUC20, MUC21) and found a total of 1858 variants. Results: After the quality filter, only 743 variants remained. Among them, we compared the frequency of each polymorphism in the LLA vs NAM group, which led to 77 variants with a significant difference, and, among these, we excluded those with LOW impact, resulting in 63. The 63 polymorphisms were distributed in 9 genes, concentrated especially in MUC 19 (n = 30) and MUC 3A (n = 18). Finally, 11 new variants were found in the NAM population. Conclusions: This is the first work with a sample of native americans with cancer, a population which is susceptible to ALL, but remains understudied. The MUC family seems to have an influence on the development of ALL in the Amerindian population, and especially MUC19 and MUC3A are shown as possible hotspots. In addition, the 11 new variants found point to the need to have their clinical impact analyzed. Keywords: MUC family; ALL; Susceptibility; Native American Populations; Brazil.

e20538 Background: Lung cancer is one of the most frequent neoplasms in the world, representing 11.4% of all registered cancers, and is responsible for 18% of cancer deaths. It is divided into two categories, small cell lung cancer, responsible for 15% of cases; and non-small cell lung cancer (NSCLC), which represents 85% of cases. The most well-known risk factor for the development of lung cancer is smoking, due to substances contained in tobacco associated with inflammation and carcinogenesis. Pulmonary carcinogenesis is a complex and gradual process, with synergistic and complex interactions between environmental risk factors and individual genetic susceptibility. The aim of this study was to investigate possible associations between TP53, PAR1, and CCR5 gene polymorphism for susceptibility to NSCLC in the Amazon. Methods: This is a pilot, case-control study, which included 263 subjects, 67 patients with NSCLC and 196 healthy subjects. The samples were analyzed for TP53 (rs17880560), PAR1 (rs11267092), and CCR5 (rs333) gene polymorphism, genotyped in PCR, followed by fragment analysis. To avoid misinterpretation due to population substructure, we applied a previously developed set of 61 informative ancestral markers that were genotyped by multiplex PCR. We used logistic regression to identify differences in genotypic frequencies between individuals with and without lung cancer. Results: We observed that some genotypes were associated with protection for NSCLC: TP53 gene LED/DEL genotype (p = 0.041, OR: 0.510, 95%CI: 0.267-0.974); DEL/DEL genotype of the PAR1 gene (p = 0.023, OR: 0.471, 95%CI: 0.247-0.971); and also the INS/INS genotype of the CCR5 gene (p = 0.033, OR: 0.331, 95%CI: 0.120-0.917). Conclusions: TP53 (rs17880560), PAR1 (rs11267092) and CCR5 (rs333) gene variants were significantly associated with NSCLC in patients from the Amazon. The validation of these findings may favor, in the future, the screening of individuals, facilitating the institution of preventive measures personalized, early diagnosis, consequently reducing the cost for health services and mortality from this malignant neoplasm. Keywords: Genetic Polymorphism; TP53; PAR1; CCR5; Biomarker; Non-Small Cell Lung Cancer.

Lung cancer is one of the most frequent neoplasms in the world. Because it is a complex disease, its formation occurs in several stages, stemming from interactions between environmental risk factors, such as smoking, and individual genetic susceptibility. Our objective was to investigate associations between a UGT1A1 gene polymorphism (rs8175347) and lung cancer risk in an Amazonian population. This is a pilot study, case-controlled study, which included 276 individuals with cancer and without cancer. The samples were analyzed for polymorphisms of the UGT1A1 gene (rs8175347) and genotyped in PCR, followed by fragment analysis in which we applied a previously developed set of informative ancestral markers. We used logistic regression to identify differences in allelic and genotypic frequencies between individuals. Individuals with the TA7 allele have an increased chance of developing lung adenocarcinoma (p = 0.035; OR: 2.57), as well as those with related genotypes of reduced or low enzymatic activity: TA6/7, TA5/7, and TA7/7 (p = 0.048; OR: 8.41). Individuals with homozygous TA7/7 have an increased chance of developing squamous cell carcinoma of the lung (p = 0.015; OR: 4.08). Polymorphism in the UGT1A1 gene (rs8175347) may contribute as a risk factor for adenocarcinoma and lung squamous cell carcinoma in the population of the Amazon region.

e15082 Background: Adverse drug reactions are an important cause of morbidity and mortality commonly found in different therapeutic regimens, particularly in oncologic. About 20-30% of these reactions are due to the individual genetic variability of patients. Pharmacogenomics focuses on the identification of genetic variants that influence drug efficacy, response, and/or toxicity by changes in pharmacokinetics/pharmacodynamics. Pharmacogenomic investigations are known to have a population bias. There is a gap in the accumulated about pharmacogenomic variants in poorly studied populations, such as the Amerindian population from the Brazilian Amazon region. The objective of this work is to describe the pharmacogenetic variability regarding 160 pharmacogenes involved in pharmacokinetic processes and biological pathways of different therapies, including oncology treatments, based on data obtained through complete exome sequencing of 64 individuals from different Amerindian groups of the Brazilian Amazon. Methods: The present study was approved by the National Committee for Ethics in Research and the Research Ethics Committee of the UFPA Tropical Medicine Center, under CAAE number 20654313.6.0000.5172. All participants signed a free-informed consent. The DNA extraction was performed using phenol-chloroform. Libraries were prepared using the Nextera Rapid Capture Exome and SureSelect Human All Exon V6 kits. Bioinformatic analysis was performed by ViVa software. Results: Our results show a total of 3,311 variants found in the study subjects. Of this, 167 are exclusive variants found in the Amerindians. Among these new variants, we found a non-synonymous coding variant in the DPYD gene with an allelic frequency of 3%, and variants with high allelic frequencies in intronic regions, which may regulate gene expression: MTHFR (5.56%), TYMS (11.5%) GSTT1 (54.1%), and three variants in the CYP2D6 gene with frequencies of 54%, 62.3%, and 65.6%. The DPYD is a pivotal gene involved with the efficacy of fluoropyrimidine-based treatment; the MTHFR and TYMS genes also participate in the biological pathways of these drugs, responsible for variation in response rates. The GSTT1 is a gene associated with platinum-based treatments, such as carboplatin and cisplatin. And, finally, CYP2D6 is one of the main pharmacogene described, involved in several drug schemes, including tamoxifen and gefitinib, used to treat breast and lung cancer, respectively. Conclusions: Understanding the diversity of genetic markers in Amazonian Amerindian is crucial to the implementation of pharmacogenomic-guided oncology treatment protocols, since pharmacogenomic data validated in other ancestral groups may not be fully applicable in these populations due to their unique genetic profile. Keywords: Exome, Native American populations, fluoropyrimidine, platinum-based drugs, tamoxifen, gefitinib.

A number of genomic variants related to native American ancestry may be associated with an increased risk of developing Acute Lymphoblastic Leukemia (ALL), which means that Latin American and hispanic populations from the New World may be relatively susceptible to this disease. However, there has not yet been any comprehensive investigation of the variants associated with susceptibility to ALL in traditional Amerindian populations from Brazilian Amazonia. We investigated the exomes of the 18 principal genes associated with susceptibility to ALL in samples of 64 Amerindians from this region, including cancer-free individuals and patients with ALL. We compared the findings with the data on populations representing five continents available in the 1000 Genomes database. The variation in the allele frequencies found between the different groups was evaluated using Fisher's exact test. The analyses of the exomes of the Brazilian Amerindians identified 125 variants, seven of which were new. The comparison of the allele frequencies between the two Amerindian groups analyzed in the present study (ALL patients vs. cancer-free individuals) identified six variants (rs11515, rs2765997, rs1053454, rs8068981, rs3764342, and rs2304465) that may be associated with susceptibility to ALL. These findings contribute to the identification of genetic variants that represent a potential risk for ALL in Amazonian Amerindian populations and might favor precision oncology measures.