Abstract The coronavirus disease 2019 (COVID-19) mortality rates varied among the states of Brazil during the course of the pandemics. The human leukocyte antigen (HLA) is a critical component of the antigen presentation pathway. Individuals with different HLA genotypes may trigger different immune responses against pathogens, which could culminate in different COVID-19 responses. HLA genotypes are variable, especially in the highly admixed Brazilian population. In this ecological study, we aimed to investigate the correlation between HLA haplotypes and the different regional distribution of COVID-19 mortality in Brazil. HLA data was obtained from 4,148,713 individuals registered in The Brazilian Voluntary Bone Marrow Donors Registry. COVID-19 data was retrieved from epidemiological bulletins issued by State Health Secretariats via Brazil’s Ministry of Health from February/2020 to July/2022. We found a positive significant correlation between the HLA-A*01~B*08~DRB1*03 haplotype and COVID-19 mortality rates when we analyzed data from 26 states and the Federal District. This result indicates that the HLA-A*01~B*08~DRB1*03 haplotype may represent an additional risk factor for dying due to COVID-19. This haplotype should be further studied in other populations for a better understanding of the variation in COVID-19 outcomes across the world. 201 COVID19 COVID 19 (COVID-19 pandemics (HLA pathway pathogens COVID-1 variable population study 4148713 4 148 713 4,148,71 Registry Brazils s February2020 February 2020 February/202 July2022 July 2022 July/2022 HLAA*01~B*08~DRB1*03 HLAA01B08DRB103 HLAABDRB A*01~B*08~DRB1*03 A 01 B 08 DRB1 03 DRB HLA-A*01~B*08~DRB1*0 2 District COVID19. 19. world 20 COVID1 1 (COVID-1 COVID- 414871 14 71 4,148,7 February202 202 February/20 July202 July/202 HLAA HLAA*01~B*08~DRB1*0 HLAA01B08DRB10 A01B08DRB103 ABDRB A*01~B*08~DRB1*0 0 HLA-A*01~B*08~DRB1* (COVID- 41487 7 4,148, February20 February/2 July20 July/20 HLAA*01~B*08~DRB1* HLAA01B08DRB1 A01B08DRB10 A*01~B*08~DRB1* HLA-A*01~B*08~DRB1 (COVID 4148 4,148 February2 February/ July2 July/2 HLAA*01~B*08~DRB1 HLAA01B08DRB A01B08DRB1 A*01~B*08~DRB1 HLA-A*01~B*08~DRB 414 4,14 July/ HLAA*01~B*08~DRB A01B08DRB A*01~B*08~DRB 41 4,1 4,

Abstract Tuberous Sclerosis Complex (TSC) is caused by loss of function germline variants in the TSC1 or TSC2 tumor suppressor genes. Genetic testing for the detection of pathogenic variants in either TSC1 or TSC2 was implemented as a diagnostic criterion for TSC. However, TSC molecular diagnosis can be challenging due to the absence of variant hotspots and the high number of variants described. This review aimed to perform an overview of TSC1/2 variants submitted in the ClinVar database. Variants of uncertain significance (VUS), missense and single nucleotide variants were the most frequent in clinical significance (37-40%), molecular consequence (37%-39%) and variation type (82%-83%) categories in ClinVar in TSC1 and TSC2 variants, respectively. Frameshift and nonsense VUS have potential for pathogenic reclassification if further functional and segregation studies were performed. Indeed, there were few functional assays deposited in the database and literature. In addition, we did not observe hotspots for variation and many variants presented conflicting submissions regarding clinical significance. This study underscored the importance of disseminating molecular diagnostic results in a public database to render the information largely accessible and promote accurate diagnosis. We encourage the performance of functional studies evaluating the pathogenicity of TSC1/2 variants. (TSC genes However described TSC12 2 TSC1/ VUS, , (VUS) 3740%, 3740 37 40% 40 (37-40%) 37%39% 3739 37% 39% 39 (37%-39% 82%83% 8283 82% 83% 82 83 (82%-83% respectively performed Indeed literature addition (VUS 3740% 374 3 4 (37-40% 37%39 373 (37%-39 82%83 828 8 (82%-83 (37-40 37%3 (37%-3 82%8 (82%-8 (37-4 (37%- (82%- (37- (37% (82% (37 (82 (3 (8 (

Abstract The TP53 3’UTR variant rs78378222 A>C has been detected in different tumor types as a somatic alteration that reduces p53 expression through modification of polyadenylation and miRNA regulation. Its prevalence is not yet known in all tumors. Herein, we examine tumor tissue prevalence of rs7837822 in Brazilian cohorts of patients from south and southeast regions diagnosed with lung adenocarcinoma (LUAD, n=586), sarcoma (SARC, n=188) and uterine leiomyoma (ULM, n=41). The minor allele (C) was identified in heterozygosity in 6/586 LUAD tumors (prevalence = 1.02 %) and none of the SARC and ULM samples. Additionally, next generation sequencing analysis revealed that all variant-positive tumors (n=4) with sample availability had additional pathogenic or likely pathogenic somatic variants in the TP53 coding regions. Among them, 3/4 (75 %) had the same pathogenic or likely pathogenic sequence variant (allele frequency <0.05 in tumor DNA) namely c.751A>C (p.Ile251Leu). Our results indicate a low somatic prevalence of rs78378222 in LUAD, ULM and SARC tumors from Brazilian patients, which suggests that no further analysis of this variant in the specific studied regions of Brazil is warranted. However, these findings should not exclude tumor molecular testing of this TP53 3’UTR functional variant for different populations. TP TP5 3UTR UTR 3 rs AC A C p p5 regulation Herein rs783782 (LUAD n=586, n586 n n=586 , 586 n=586) SARC, (SARC n=188 n188 188 ULM, (ULM n=41. n41 n=41 . 41 n=41) (C 6586 6 6/58 102 1 02 1.0 % samples Additionally variantpositive positive n=4 n4 4 (n=4 them 34 3/ 75 (7 005 0 05 <0.0 DNA c751AC cAC c 751A p.Ile251Leu. pIle251Leu pIleLeu p.Ile251Leu Ile251Leu Ile Leu (p.Ile251Leu) warranted However populations rs78378 n58 n=58 58 n=18 n18 18 658 6/5 10 1. n= (n= 7 ( 00 <0. pIle IleLeu (p.Ile251Leu rs7837 n5 n=5 5 n=1 n1 65 6/ (n <0 rs783 < rs78 rs7

Abstract Tuberous sclerosis complex (TSC) is an autosomal dominant genetic disorder caused by germline mutations in TSC1 or TSC2 genes, which leads to the hyperactivation of the mTORC1 pathway, an important negative regulator of autophagy. This leads to the development of hamartomas in multiple organs. The variability in symptoms presents a challenge for the development of completely effective treatments for TSC. One option is the treatment with mTORC1 inhibitors, which are targeted to block cell growth and restore autophagy. However, the therapeutic effect of rapamycin seems to be more efficient in the early stages of hamartoma development, an effect that seems to be associated with the paradoxical role of autophagy in tumor establishment. Under normal conditions, autophagy is directly inhibited by mTORC1. In situations of bioenergetics stress, mTORC1 releases the Ulk1 complex and initiates the autophagy process. In this way, autophagy promotes the survival of established tumors by supplying metabolic precursors during nutrient deprivation; paradoxically, excessive autophagy has been associated with cell death in some situations. In spite of its paradoxical role, autophagy is an alternative therapeutic strategy that could be explored in TSC. This review compiles the findings related to autophagy and the new therapeutic strategies targeting this pathway in TSC.

Abstract Tuberous sclerosis complex (TSC) is an autosomal dominant cancer predisposition disorder caused by heterozygous mutations in TSC1 or TSC2 genes and characterized by mTORC1 hyperactivation. TSC-associated tumors develop after loss of heterozygosity mutations and their treatment involves the use of mTORC1 inhibitors. We aimed to evaluate cellular processes regulated by mTORC1 in TSC cells with different mutations before tumor development. Flow cytometry analyses were performed to evaluate cell viability, cell cycle and autophagy in non-tumor primary TSC cells with different heterozygous mutations and in control cells without TSC mutations, before and after treatment with rapamycin (mTORC1 inhibitor). We did not observe differences in cell viability and cell cycle between the cell groups. However, autophagy was reduced in mutated cells. After rapamycin treatment, mutated cells showed a significant increase in the autophagy process (p=0.039). We did not observe differences between cells with distinct TSC mutations. Our main finding is the alteration of autophagy in non-tumor TSC cells. Previous studies in literature found autophagy alterations in tumor TSC cells or knock-out animal models. We showed that autophagy could be an important mechanism that leads to TSC tumor formation in the haploinsufficiency state. This result could guide future studies in this field.

Abstract In Brazil, the population in general has little knowledge about genetic risks, as well as regarding the role and importance of the Cancer Genetic Counseling (CGC). The goal of this study was to evaluate cancer-related worry and cancer risk perception during CGC sessions in Brazilian women at-risk for hereditary breast cancer. This study was performed in 264 individuals seeking CGC for hereditary breast cancer. Both cancer-affected and unaffected individuals were included. As results, individuals with and without cancer reported different motivations for seeking CGC and undergoing genetic testing. A correlation was observed between age at the first CGC session and age at which the closest relative was diagnosed with cancer. Multivariate analysis showed that educational level, cancer risk discussion within the family, and number of deaths by cancer among first-degree relatives influenced positively the cancer risk perception. In conclusion, the results of this study indicate that cancer-related worry and cancer risk perception are significant aspects of morbidity in individuals seeking CGC, whether they are cancer-affected or unaffected. CGC has an important role in health education and cancer prevention for its potential of promoting an accurate perception of the risk.

Abstract Germline mutations in BRCA1 and BRCA2 (BRCA) genes confer high risk of developing cancer, especially breast and ovarian tumors. Since the cloning of these tumor suppressor genes over two decades ago, a significant amount of research has been done. Most recently, monoallelic loss-of-function mutations in PALB2 have also been shown to increase the risk of breast cancer. The identification of BRCA1, BRCA2 and PALB2 as proteins involved in DNA double-strand break repair by homologous recombination and of the impact of complete loss of BRCA1 or BRCA2 within tumors have allowed the development of novel therapeutic approaches for patients with germline or somatic mutations in said genes. Despite the advances, especially in the clinical use of PARP inhibitors, key gaps remain. Now, new roles for BRCA1 and BRCA2 are emerging and old concepts, such as the classical two-hit hypothesis for tumor suppression, have been questioned, at least for some BRCA functions. Here aspects regarding cancer predisposition, cellular functions, histological and genomic findings in BRCA and PALB2-related tumors will be presented, in addition to an up-to-date review of the evolution and challenges in the development and clinical use of PARP inhibitors.

Abstract Breast cancer (BC) risk assessment models base their estimations on different aspects of a woman’s personal and familial history. The Gail and Tyrer–Cuzick models are the most commonly used, and BC risks assigned by them vary considerably especially concerning familial history. In this study, our aim was to compare the Gail and Tyrer-Cuzick models after initial screening for familial history of cancer in primary care using the FHS-7 questionnaire. We compared 846 unrelated women with at least one positive answer to any of the seven FHS-7 questions (positive group) and 892 unrelated women that answered negatively (negative group). Concordance between BC risk estimates was compared by Bland-Altman graphics. Mean BC risk estimates were higher using the Tyrer-Cuzick Model in women from the positive group, while women from the negative group had higher BC risk estimates using the Gail model. With increasing estimates, discordance also increased, mainly in the FHS-7 positive group. Our results show that in women with a familial history of cancer, the Gail model underestimates risk and the Tyrer-Cuzick seems to be more appropriate. FHS-7 can be a useful tool for the identification of women with higher breast cancer risks in the primary care setting.

Abstract Tuberous sclerosis complex is an autosomal dominant disorder characterized by skin manifestations and formation of multiple tumors in different organs, mainly in the central nervous system. Tuberous sclerosis is caused by the mutation of one of two tumor suppressor genes, TSC1 or TSC2. Currently, the development of novel techniques and great advances in high-throughput genetic analysis made mutation screening of the TSC1 and TSC2 genes more widely available. Extensive studies of the TSC1 and TSC2 genes in patients with TSC worldwide have revealed a wide spectrum of mutations. Consequently, the discovery of the underlying genetic defects in TSC has furthered our understanding of this complex genetic disorder, and genotype-phenotype correlations are becoming possible, although there are still only a few clearly established correlations. This review focuses on the main symptoms and genetic alterations described in TSC patients from 13 countries in three continents, as well as on genotype-phenotype correlations established to date. The determination of genotype-phenotype correlations may contribute to the establishment of successful personalized treatment for TSC.

Abstract Approximately 5-10% of breast cancers are caused by germline mutations in high penetrance predisposition genes. Among these, BRCA1 and BRCA2, which are associated with the Hereditary Breast and Ovarian Cancer (HBOC) syndrome, are the most frequently affected genes. Recent studies confirm that gene rearrangements, especially in BRCA1, are responsible for a significant proportion of mutations in certain populations. In this study we determined the prevalence of BRCA rearrangements in 145 unrelated Brazilian individuals at risk for HBOC syndrome who had not been previously tested for BRCA mutations. Using Multiplex Ligation-dependent Probe Amplification (MLPA) and a specific PCR-based protocol to identify a Portuguese founder BRCA2 mutation, we identified two (1,4%) individuals with germline BRCA1 rearrangements (c.547+240_5193+178del and c.4675+467_5075-990del) and three probands with the c.156_157insAlu founder BRCA2 rearrangement. Furthermore, two families with false positive MLPA results were shown to carry a deleterious point mutation at the probe binding site. This study comprises the largest Brazilian series of HBOC families tested for BRCA1 and BRCA2 rearrangements to date and includes patients from three regions of the country. The overall observed rearrangement frequency of 3.44% indicates that rearrangements are relatively uncommon in the admixed population of Brazil.

Abstract In Brazil, breast cancer is a public health care problem due to its high incidence and mortality rates. In this study, we investigated the prevalence of hereditary breast cancer syndromes (HBCS) in a population-based cohort in Brazils southernmost capital, Porto Alegre. All participants answered a questionnaire about family history (FH) of breast, ovarian and colorectal cancer and those with a positive FH were invited for genetic cancer risk assessment (GCRA). If pedigree analysis was suggestive of HBCS, genetic testing of the BRCA1, BRCA2, TP53, and CHEK2 genes was offered. Of 902 women submitted to GCRA, 214 had pedigrees suggestive of HBCS. Fifty of them underwent genetic testing: 18 and 40 for BRCA1/BRCA2 and TP53 mutation screening, respectively, and 7 for CHEK2 1100delC testing. A deleterious BRCA2 mutation was identified in one of the HBOC probands and the CHEK2 1100delC mutation occurred in one of the HBCC families. No deleterious germline alterations were identified in BRCA1 or TP53. Although strict inclusion criteria and a comprehensive testing approach were used, the suspected genetic risk in these families remains unexplained. Further studies in a larger cohort are necessary to better understand the genetic component of hereditary breast cancer in Southern Brazil.

Abstract Germline mutations in the TP53 gene are associated with Li-Fraumeni and Li-Fraumeni-Like Syndromes, characterized by increased predisposition to early-onset cancers. In Brazil, the prevalence of the TP53-p.R337H germline mutation is exceedingly high in the general population and in cancer-affected patients, probably as result of a founder effect. Several genotyping methods are used for the molecular diagnosis of LFS/LFL, however Sanger sequencing is still considered the gold standard. We compared performance, cost and turnaround time of Sanger sequencing, PCR-RFLP, TaqMan-PCR and HRM in the p.R337H genotyping. The performance was determined by analysis of 95 genomic DNA samples and results were 100% concordant for all methods. Sequencing was the most expensive method followed by TaqMan-PCR, PCR-RFLP and HRM. The overall cost of HRM increased with the prevalence of positive samples, since confirmatory sequencing must be performed when a sample shows an abnormal melting profile, but remained lower than all other methods when the mutation prevalence was less than 2.5%. Sequencing had the highest throughput and the longest turnaround time, while TaqMan-PCR showed the lowest turnaround and hands-on times. All methodologies studied are suitable for the detection of p.R337H and the choice will depend on the application and clinical scenario.