COVID-19 in Brazilian Pediatric Patients: A Retrospective Cross-Sectional Study with a Predictive Model for Hospitalization.

BACKGROUND: This study was conducted to ascertain the most frequent symptoms of COVID-19 infection at first consultation in a pediatric cohort and to devise a predictive model for hospitalization. METHODS: This is a retrospective cross-sectional study of 1028 Brazilian patients aged <18 years with SARS-CoV-2 infection in a single reference hospital in the first year of the pandemic. Clinical, demographic, laboratory, and disease spectrum data were analyzed via multivariate logistic regression modeling to develop a predictive model of factors linked to hospitalization. RESULTS: The majority of our cohort were schoolchildren and adolescents, with a homogeneous distribution concerning sex. At first consultation, most patients presented with fever (64.1%) and respiratory symptoms (63.3%). We had 204 admitted patients, including 11 with Pediatric Multisystem Inflammatory Syndrome. Increased D-dimer levels were associated with comorbidities (p = 0.018). A high viral load was observed in patients within the first two days of symptoms (p < 0.0001). Our predictive model included respiratory distress, number and type of specific comorbidities, tachycardia, seizures, and vomiting as factors for hospitalization. CONCLUSIONS: Most patients presented with mild conditions with outpatient treatment. However, understanding predictors for hospitalization can contribute to medical decisions at the first patient visit.

From Acute Phase to Long COVID: A Cross-Sectional Study of the Epidemiological Profile and Clinical Evaluation of SARS-CoV-2 Infection in Employees at a Pediatric Hospital.

BACKGROUND: The coronavirus disease 2019 (COVID-19) pandemic began in Brazil on 26 February 2020. By 6 May 2023, 37.4 million cases had been confirmed, causing 701 thousand deaths in the country. We aimed to describe the epidemiological profile and clinical development of COVID-19 cases among the employees of a health institution, from acute infection to long COVID. METHODS: This was a longitudinal study using a retrospective and prospective approach via questionnaires referring to epidemiological investigation, which was the inclusion criteria, and about long-term symptoms. RESULTS: A total of 809 employees were detected with SARS-CoV-2 infection via RT-PCR, 466 of them answered the epidemiological investigation, and 101 completed the Long COVID Symptom Questionnaire. The most commonly affected employees were women (88.6%) working in patient care (68.6%). Headache, myalgia, cough, odynophagia, and runny nose were the most frequent symptoms. Only three employees (0.6%) required hospitalization, while the other employees required outpatient management due to mild symptoms. We identified 19 (4.1%) cases of reinfection, and 42 (41.6%) employees reported long-term symptoms, such as myalgia, dyspnea, and headache. CONCLUSIONS: Although most cases were mild with good outcomes, long COVID cases identified are noteworthy, as these symptoms may impact quality of life even months after SARS-CoV-2 infection.

Biomarkers associated with persistence and severity of IgE-mediated food allergies: a systematic review.

OBJECTIVE: The prevalence of food allergies (FA) has increased worldwide over the last few decades. Milk, eggs, and peanuts are among the most common allergens and can cause anaphylaxis. Therefore, we aimed to identify biomarkers that could predict the persistence and/or severity of IgE-mediated allergies to milk, eggs, and peanuts via a systematic review. METHODS: This systematic review proceeded according to a protocol registered in the International Prospective Register of Systematic Reviews. Two independent authors extracted studies of interest from PubMed, SciELO, EMBASE, Scopus, and Ebsco databases and assessed their quality using the Newcastle-Ottawa Scale. RESULTS: We selected 14 articles describing 1,398 patients. Among eight identified biomarkers, total IgE, specific IgE (sIgE), and IgG4 were the most often cited biomarkers of persistent allergies to milk, eggs, and peanuts. Skin prick tests, endpoint tests, and sIgE cutoff levels may predict positive responses to challenges with these foods. The basophil activation test is a biomarker for the severity and/or threshold of allergic reactions to milk and peanuts. CONCLUSION: Only a few publications identified possible prognostic indicators of the persistence or severity of FA and outcomes of oral food challenges, indicating that more accessible biomarkers are needed to determine the likelihood of having a severe food allergic reaction.

Polymorphism in cytolytic pathway genes in patients with pediatric inflammatory multisystemic syndrome temporally associated with SARS-CoV-2 / Polimorfismos em genes da via citolítica em pacientes com síndrome inflamatória multissistêmica pediátrica temporariamente associada ao SARS-CoV-2

Introduction: Pediatric inflammatory multisystem syndrome temporally associated with SARS-CoV-2 (PIMS-TS) is a systemic hyperinflammatory disease that occurs in a small number of children after being infected with SARS-CoV-2. Macrophage activation syndrome, an aggressive condition characterized by the excessive inflammation and activation of well-differentiated macrophages, has been shown to occur in patients infected by SARS-CoV-2. Considering the clinical and pathophysiological similarities between these diseases, our main objective was to determine whether gene polymorphisms associated with macrophage activation syndrome were also present in patients with PIMS-TS. Methods: DNA from 10 pediatric patients with PIMS-TS (case group) and ten COVID-19 patients without PIMS-TS (control group) were genotyped by Real-time PCR analysis (TaqMan®) for single nucleotide polymorphisms (SNP) in four genes associated with macrophage activation syndrome: perforin 1 (PRF1), granzyme B (GZMB), syntaxin 11 (STX11), and syntaxin binding protein 2 (STXBP2). The SNP analysis was performed using the additive, dominant, and recessive models. Results: A significantly higher frequency of an SNP (C wild allele in rs6573910) in the GZMB gene was observed in both the additive and dominant models in the PIMS-TS group than controls. A borderline significant difference was also observed for the G allele in rs7764017 of the STX11 gene in the PIMS-TS group in the additive model. Conclusions: This study indicated the presence of two polymorphisms in genes associated with macrophage activation syndrome (GZMB and STX11) in patients who developed PIMS-TS. If the presence of these SNPs is validated in a larger number of PIMS-TS cases, they can be used as potential biomarkers for early identification of pediatric patients with a higher probability of developing PIMS-TS associated with SARS-CoV-2 infection.

Introdução: A síndrome multissistêmica inflamatória pediátrica temporariamente associada ao SARS-CoV-2 (SIMP-TS) é uma doença hiperinflamatória sistêmica que ocorre em um pequeno número de crianças após serem infectadas pelo SARS-CoV-2. A síndrome de ativação de macrófagos (SAM), uma condição agressiva caracterizada pela inflamação excessiva e ativação de macrófagos bem diferenciados, demonstrou ocorrer em pacientes infectados por SARS-CoV-2. Considerando as semelhanças clínicas e fisiopatológicas entre essas doenças, neste estudo o nosso principal objetivo foi determinar se polimorfismos gênicos associados à SAM também estavam presentes em pacientes com SIMP-TS. Métodos: DNA de dez pacientes pediátricos com SIMP (grupo caso) e dez pacientes COVID-19 sem SIMP (grupo controle) foram genotipados por análise de PCR em tempo real (tecnologia TaqMan®) para polimorfismos de nucleotídeo único (SNPs) em quatro genes selecionados associados com SAM: perforina 1 (PRF1), granzima B (GZMB), sintaxina 11 (STX11) e proteína de ligação de sintaxina 2 (STXBP2). A análise dos SNPs foi realizada utilizando o modelo aditivo, dominante e recessivo. Resultados: Uma frequência significativamente maior de um SNP (alelo selvagem C em rs6573910) no gene GZMB foi observada pelos modelos aditivo e dominante no grupo SIMP quando comparado aos controles. Além disso, uma significância limítrofe foi observada para o alelo G em rs7764017 do gene STX11 no grupo SIMP pelo modelo aditivo. Conclusões: Nosso estudo indicou a presença de dois polimorfismos em genes associados à SAM (GZMB e STX11) em pacientes que desenvolveram SIMP-TS. Uma vez validada a presença desses SNPs em um número maior de casos de SIMP-TS, eles podem ser usados como potenciais biomarcadores para a identificação precoce de pacientes pediátricos com maior probabilidade de desenvolver SIMP-TS associado à infecção por SARS-CoV-2.

Immune reconstitution after allogenic stem cell transplantation: An observational study in pediatric patients.

INTRODUCTION: The immune reconstitution (IR) after the allogenic hematopoietic stem cell transplantation (allo-HSCT) is a progressive process intrinsically correlated to the therapeutic success. It is essential to understand the interfering factors in IR to prevent the HSCT-related mortality. METHODS: We retrospectively evaluated the clinical outcomes, absolute lymphocyte counts (ALCs) and lymphocyte subtypes at different time-points of 111 pediatric patients with allogeneic HSCT for malignant and non-malignant diseases from 2013 to 2018. RESULTS: The ALCs gradually increased on D+30, D+100, and D+180 (medians 634/µL, 1022/µL and 1541/µL, respectively). On D+100, the CD3+CD8+ achieved the highest recovery rate (68%), followed by the CD16+CD56+ (47%), CD3+CD4+ (39%) and CD19+ (8%). The adequate ALC recovery was associated with age < 8 years, bone marrow grafts, myeloablative conditioning, non-use of serotherapy and non-haploidentical donors. The ALC and CD3+CD8+ on D+100 counts were higher in patients with the cytomegalovirus infection. The CD3+CD4+ recovery was associated with an age < 8 years, a non-malignant disease and a lower incidence of acute graft-versus-host disease ≥ grade 2. Furthermore, the ALC recovery on D+100 resulted in a higher overall survival, regardless of the disease type (HR 3.65, 1.05 - 12.71, p = 0.04). CONCLUSION: Several factors influenced the IR after the allo-HSCT. The ALC ≥ 500/µL on D+100 was a simple IR predictor of survival, easily available to resource-limited centers.

Biomarkers associated with persistence and severity of IgE-mediated food allergies: a systematic review

Abstract Objective The prevalence of food allergies (FA) has increased worldwide over the last few decades. Milk, eggs, and peanuts are among the most common allergens and can cause anaphylaxis. Therefore, we aimed to identify biomarkers that could predict the persistence and/or severity of IgE-mediated allergies to milk, eggs, and peanuts via a systematic review. Methods This systematic review proceeded according to a protocol registered in the International Prospective Register of Systematic Reviews. Two independent authors extracted studies of interest from PubMed, SciELO, EMBASE, Scopus, and Ebsco databases and assessed their quality using the Newcastle-Ottawa Scale. Results We selected 14 articles describing 1,398 patients. Among eight identified biomarkers, total IgE, specific IgE (sIgE), and IgG4 were the most often cited biomarkers of persistent allergies to milk, eggs, and peanuts. Skin prick tests, endpoint tests, and sIgE cutoff levels may predict positive responses to challenges with these foods. The basophil activation test is a biomarker for the severity and/or threshold of allergic reactions to milk and peanuts. Conclusion Only a few publications identified possible prognostic indicators of the persistence or severity of FA and outcomes of oral food challenges, indicating that more accessible biomarkers are needed to determine the likelihood of having a severe food allergic reaction.

Immune reconstitution after allogenic stem cell transplantation: An observational study in pediatric patients

Abstract Introduction The immune reconstitution (IR) after the allogenic hematopoietic stem cell transplantation (allo-HSCT) is a progressive process intrinsically correlated to the therapeutic success. It is essential to understand the interfering factors in IR to prevent the HSCT-related mortality. Methods We retrospectively evaluated the clinical outcomes, absolute lymphocyte counts (ALCs) and lymphocyte subtypes at different time-points of 111 pediatric patients with allogeneic HSCT for malignant and non-malignant diseases from 2013 to 2018. Results The ALCs gradually increased on D+30, D+100, and D+180 (medians 634/μL, 1022/μL and 1541/μL, respectively). On D+100, the CD3+CD8+ achieved the highest recovery rate (68%), followed by the CD16+CD56+ (47%), CD3+CD4+ (39%) and CD19+ (8%). The adequate ALC recovery was associated with age < 8 years, bone marrow grafts, myeloablative conditioning, non-use of serotherapy and non-haploidentical donors. The ALC and CD3+CD8+ on D+100 counts were higher in patients with the cytomegalovirus infection. The CD3+CD4+ recovery was associated with an age < 8 years, a non-malignant disease and a lower incidence of acute graft-versus-host disease ≥ grade 2. Furthermore, the ALC recovery on D+100 resulted in a higher overall survival, regardless of the disease type (HR 3.65, 1.05 - 12.71, p= 0.04). Conclusion Several factors influenced the IR after the allo-HSCT. The ALC ≥ 500/μL on D+100 was a simple IR predictor of survival, easily available to resource-limited centers.

CD40 Ligand Deficiency in Latin America: Clinical, Immunological, and Genetic Characteristics.

CD40 ligand (CD40L) deficiency is a rare inborn error of immunity presenting with heterogeneous clinical manifestations. While a detailed characterization of patients affected by CD40L deficiency is essential to an accurate diagnosis and management, information about this disorder in Latin American patients is limited. We retrospectively analyzed data from 50 patients collected by the Latin American Society for Immunodeficiencies registry or provided by affiliated physicians to characterize the clinical, laboratory, and molecular features of Latin American patients with CD40L deficiency. The median age at disease onset and diagnosis was 7 months and 17 months, respectively, with a median diagnosis delay of 1 year. Forty-seven patients were genetically characterized revealing 6 novel mutations in the CD40LG gene. Pneumonia was the most common first symptom reported (66%). Initial immunoglobulin levels were variable among patients. Pneumonia (86%), upper respiratory tract infections (70%), neutropenia (70%), and gastrointestinal manifestations (60%) were the most prevalent clinical symptoms throughout life. Thirty-five infectious agents were reported, five of which were not previously described in CD40L deficient patients, representing the largest number of pathogens reported to date in a cohort of CD40L deficient patients. The characterization of the largest cohort of Latin American patients with CD40L deficiency adds novel insights to the recognition of this disorder, helping to fulfill unmet needs and gaps in the diagnosis and management of patients with CD40L deficiency.

CD40L modulates transcriptional signatures of neutrophils in the bone marrow associated with development and trafficking.

Neutrophils are produced in the BM in a process called granulopoiesis, in which progenitor cells sequentially develop into mature neutrophils. During the developmental process, which is finely regulated by distinct transcription factors, neutrophils acquire the ability to exit the BM, properly distribute throughout the body, and migrate to infection sites. Previous studies have demonstrated that CD40 ligand (CD40L) influences hematopoiesis and granulopoiesis. Here, we investigate the effect of CD40L on neutrophil development and trafficking by performing functional and transcriptome analyses. We found that CD40L signaling plays an essential role in the early stages of neutrophil generation and development in the BM. Moreover, CD40L modulates transcriptional signatures, indicating that this molecule enables neutrophils to traffic throughout the body and to migrate in response to inflammatory signals. Thus, our study provides insights into the complex relationships between CD40L signaling and granulopoiesis, and it suggests a potentially novel and nonredundant role of CD40L signaling in neutrophil development and function.

Immunity and inflammatory biomarkers in COVID-19: A systematic review.

Coronavirus disease 2019 (COVID-19) is a clinical syndrome caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus. Patients can be asymptomatic or present respiratory and gastrointestinal symptoms, and even multiple-organ failure which can lead to death. The balance between an effective antiviral response and dysregulated immune response is the key factor determining the severity of COVID-19 progression. A systematic review was performed using the NCBI-PubMed database to find the articles related to COVID-19 immunity and inflammatory response published from 1 December 2019 to 15 April 2020. Haematological, immunological and biochemical parameters were extracted and correlated with disease severity, age and presence of comorbidities. Twelve articles were analysed comprising a total of 1042 hospitalized patients infected with SARS-CoV-2 and 95 different parameters. Total lymphocyte count and levels of CD3+ and CD4+ T cells were decreased in severe and critical cases. Neutrophilia was found in patients who progressed to acute respiratory distress syndrome (ARDS). Interleukin-six (IL-6) was high in mild and severe patients regardless of comorbidities. Erythrocyte sedimentation rate (ESR) and count and C-reactive protein (CRP) levels were increased regardless of disease severity or presence of comorbidities. High levels of D-dimer and lactate dehydrogenase were present in diabetic patients and patients who developed ARDS. Procalcitonin levels were elevated to varying degrees in severe and critical patients. We conclude that the total lymphocyte count, CD3+ and CD4+ T cells are low, especially in severe and critical COVID-19 patients; ESR, CRP and IL-6 were elevated, independent of the severity of disease. Understanding the inflammatory response of COVID-19 patients is essential for the development of better therapeutic and management strategies.

Outcome of SARS-CoV-2 Infection in 121 Patients with Inborn Errors of Immunity: A Cross-Sectional Study.

PURPOSE: There is still scarce data on SARS-CoV-2 infection in patients with Inborn Errors of Immunity (IEI) and many unresolved questions. We aimed to describe the clinical outcome of SARS-CoV-2 infection in Brazilian IEI patients and identify factors influencing the infection. METHODS: We did a cross-sectional, multicenter study that included patients of any age affected by IEI and SARS-CoV-2 infection. The variables studied were sex, age, type of IEI, comorbidities (number and type), treatment in use for IEI, clinical manifestations and severity of SARS-CoV-2 infection. RESULTS: 121 patients were included: 55.4% female, ages from six months to 74 yo (median age = 25.1 yo). Most patients had predominantly antibody deficiency (n = 53). The infection was mostly asymptomatic (n = 21) and mild (n = 66), and one child had multisystem inflammatory syndrome (MIS-C). We could not observe sex-related susceptibility, and there was a weak correlation between age and severity of infection. The number of comorbidities was higher in severe cases, particularly bronchiectasis and cardiopathy. There were no severe cases in hereditary angioedema patients. Six patients aged 2 to 74 years died, three of them with antibody deficiency. CONCLUSION: The outcome was mild in most patients, but the Case Fatality Ratio was higher than in the general population. However, the type of IEI was not a determining factor for severity, except for complement deficiencies linked to milder COVID-19. The severity of SARS-CoV-2 infection seems to be more related to older age, a higher number of comorbidities and type of comorbidities (bronchiectasis and cardiopathy).

Vacinas COVID-19 e outros imunobiológicos ­ intervalos preconizados / COVID-19 vaccines and other immunobiological drugs ­ recommended intervals

Com o início do programa de vacinação contra a COVID-19 no Brasil, surgiu uma série de questionamentos relacionados ao uso dos imunizantes. Neste documento, o grupo de estudo da COVID-19 da Associação Brasileira de Alergia e Imunologia (ASBAI) avalia as evidências científicas e se posiciona em relação aos intervalos preconizados entre a administração das vacinas contra o SARS-CoV-2 e dos imunobiológicos.

With the beginning of the COVID-19 vaccination program in Brazil, a series of questions related to the use of vaccines arose. In this document, the COVID-19 study group of the Brazilian Association of Allergy and Immunology (ASBAI) assesses the scientific evidence and takes a stand for the recommended intervals between the administration of SARS-CoV-2 vaccines and that of immunobiological drugs.

Extreme phenotypes approach to investigate host genetics and COVID-19 outcomes.

COVID-19 comprises clinical outcomes of SARS-CoV-2 infection and is highly heterogeneous, ranging from asymptomatic individuals to deceased young adults without comorbidities. There is growing evidence that host genetics play an important role in COVID-19 severity, including inborn errors of immunity, age-related inflammation and immunosenescence. Here we present a brief review on the known order of events from infection to severe system-wide disturbance due to COVID-19 and summarize potential candidate genes and pathways. Finally, we propose a strategy of subject's ascertainment based on phenotypic extremes to take part in genomic studies and elucidate intrinsic risk factors involved in COVID-19 severe outcomes.

Reinfecções pelo SARS-CoV-2: fato ou fake ? Implicações para a resposta vacinal / Reinfection with SARS-CoV-2: fact or fake? Implications for vaccine response

Há evidências atuais de que a reinfecção pelo SARS-CoV-2 é uma realidade, mas na grande maioria das situações não houve investigação que permitisse sua perfeita caracterização, sendo confirmados poucos casos. Em situações de real reinfecção, esta ocorreu, em sua grande maioria, por variantes do vírus, com diversas mutações, usualmente na proteína da espícula viral, em profissionais de saúde altamente expostos, ou em portadores de imunodeficiências, tanto primárias quanto secundárias. Ressaltamos que as vacinas podem ser modificadas com relativa facilidade, mas a capacidade de fabricação e de distribuição pelo mundo será capaz de acompanhar a demanda por vacinação em massa de forma eficiente? Neste manuscrito, a comissão de estudo da COVID-19 da ASBAI analisa criticamente o conhecimento atual sobre a reinfecção pelo SARS-CoV-2.

There is current evidence that reinfection with SARS-CoV-2 is a reality, but there is also a lack of investigation that would allow its perfect characterization, and few cases have been confirmed. Real reinfections occurred mostly with variants of the virus, with several mutations, usually in the viral spike protein, in highly exposed health professionals or in patients with immunodeficiencies, both primary and secondary. We emphasize that vaccines can be modified relatively easily, but will the manufacturing and distribution capacity around the world be able to keep up with the demand for mass vaccination efficiently? The ASBAI COVID-19 study commission critically analyzes in this manuscript the current knowledge about SARS-CoV-2 reinfection.

Alergias e vacinas contra a COVID-19 / Allergies and vaccines against COVID-19

As vacinas são reconhecidas como uma das conquistas do século passado de maior impacto em Saúde Pública, reduzindo de modo significativo a morbidade e mortalidade associadas a grande número de doenças infecciosas. No entanto, em casos raros, as vacinas podem causar doença ou eventos adversos pós-vacinação (EAPV). Os imunologistas clínicos e alergistas possuem um papel muito importante nesse momento em que mundialmente buscamos imunizar a população contra a COVID- 19. Eles devem fornecer apoio aos indivíduos orientando sobre o diagnóstico e tratamento de EAPV, incluindo anafilaxia, e, ainda, apoiar e encorajar os pacientes a se vacinarem, mesmo após eventos adversos, desde que leves ou moderados.

Vaccines are known as one of the achievements of the last century with greatest impact on public health, significantly reducing morbidity and mortality associated with a large number of infectious diseases. However, in rare cases, vaccines may cause disease or adverse events following immunization. Clinical immunologists and allergists have a very important role in the worldwide vaccination against COVID-19. They should provide support to individuals by advising on the diagnosis and treatment of adverse events following immunization, including anaphylaxis, and also support and encourage patients to be vaccinated, even after adverse events, as long as they are mild or moderate.

Vacinas contra a COVID-19 e os erros inatos da imunidade (ou imunodeficiências primárias) / COVID-19 vaccines and inborn errors of immunity (or primary immunodeficiencies)

Desde o início da pandemia de COVID-19 iniciou-se a corrida por uma imunização ativa, eficaz e segura. Todas as vacinas desenvolvidas até o momento vêm demostrando boa eficácia na prevenção de casos graves de COVID-19, de hospitalizações e mortes. Muitos pacientes com erros inatos da imunidade (EII) não terão capacidade de desenvolver uma resposta imune semelhante ao indivíduo imunocompetente. Esses pacientes foram incluídos nos grupos prioritários definidos pelo Ministério da Saúde, como pessoas entre 18 a 59 anos com uma ou mais das comorbidades, incluindo as imunodeficiências primárias. Eles podem e devem receber as vacinas em uso contra o SARS-CoV-2, mas nem sempre apresentarão uma resposta imunológica satisfatória e protetora, e, portanto, seus contactantes também devem ser vacinados.

Since the beginning of the COVID-19 pandemic, the race for an active, effective, and safe immunization has started. All vaccines developed to date have shown good efficacy in preventing serious cases of COVID-19, hospitalization, and death. Many patients with inborn errors of immunity will not be able to develop an immune response similar to that of immunocompetent individuals. These patients were included in the priority groups defined by the Brazilian Ministry of Health, as people between 18 and 59 years of age with one or more comorbidities, including primary immunodeficiencies. They can and should receive the vaccines in use against SARS-CoV-2, but they will not always have a satisfactory and protective immune response, and, therefore, those in direct contact with them should also be vaccinated.

Frequency of the TP53 R337H variant in sporadic breast cancer and its impact on genomic instability.

The R337H is a TP53 germline pathogenic variant that has been associated with several types of cancers, including breast cancer. Our main objective was to determine the frequency of the R337H variant in sporadic breast cancer patients from Paraná state, South Brazil, its association with prognosis and its impact in genomic instability. The genotyping of 805 breast cancer tissues revealed a genotypic and allelic frequency of the R337H variant of 2.36% and 1.18%, respectively. In these R337H+ cases a lower mean age at diagnosis was observed when compared to the R337H-cases. Array-CGH analysis showed that R337H+ patients presented a higher number of copy number alterations (CNAs), compared to the R337H-. These CNAs affected genes and miRNAs that regulate critical cancer signaling pathways; a number of these genes were associated with survival after querying the KMplot database. Furthermore, homozygous (R337H+/R337H+) fibroblasts presented increased levels of copy number variants when compared to heterozygous or R337H- cells. In conclusion, the R337H variant may contribute to 2.36% of the breast cancer cases without family cancer history in Paraná. Among other mechanisms, R337H increases the level of genomic instability, as evidenced by a higher number of CNAs in the R337H+ cases compared to the R337H-.