Medical Genetics in Brazil in the 21st Century: A Thriving Specialty and Its Incorporation in Public Health Policies.

Brazil is a continent-size country with 203 million inhabitants, classified as a developing upper-middle-income country, although inequities remain significant. Most of the population is assisted by the public Unified Health System (SUS), along with a thriving private health sector. Congenital malformations are the second leading cause of infant mortality and chronic/genetic disorders and a significant burden in hospital admissions. The past two decades have been crucial for formalizing medical genetics as a recognized medical specialty in the SUS, as well as for implementing a new health policy by the Ministry of Health for comprehensive care for rare diseases. These public health policies had the broad support of the Brazilian Society of Medical Genetics and Genomics and patient organizations. Most comprehensive genetic services are concentrated in large urban centers in the South and Southeast regions of Brazil; with this new policy, new services throughout the country are progressively being integrated. The number of medical geneticists increased by 103% in a decade. Details on the policy and an overview of the availability of services, testing, human resources, newborn screening, research projects, patient organizations, and relevant issues regarding medical genetics in this vast and diverse country are presented.

Risk for Hereditary Neoplastic Syndromes in Women with Mismatch Repair-Proficient Endometrial Cancer.

Endometrial cancer (EC) is a prevalent malignancy in women, and those who are proficient in the DNA mismatch repair (pMMR) pathway may have a family history (FH) that meets the criteria for a hereditary neoplastic condition (HNS). This study aimed to estimate the risk of HNS in women with pMMR endometrial tumors by analyzing their FH. To achieve this, we collaborated with a primary study and collected FH information by telephone. The final sample comprised 42 women who responded to the Primary Screening Questionnaire. Their family pedigrees were drawn and categorized according to internationally standardized criteria for the risk of HNS. Results showed that 26 women (61%) were found to be at risk for HNS, with Bethesda criteria being met by 23%, Amsterdam criteria by 15%, and 4% met the attenuated familial adenomatous polyposis criteria. Our results emphasize the importance of FH and the need to encourage healthcare professionals to collect and document FH more frequently, even if it is self-reported. By identifying individuals with HNS, we can improve their outcomes and reduce the burden of cancer in families with a predisposition to cancer.

Health Policies for Rare Disease Patients: A Scoping Review.

OBJECTIVE: To identify and map the available evidence on the implementation of public health policies directed at individuals with rare diseases, and to compare the implementation of these health policies between Brazil and other countries. METHOD: A scoping review guided by the PRISMA-ScR and JBI checklists. The search for articles was conducted in eight electronic databases, MEDLINE/Pubmed, Embase, Cochrane Library, Web of Science, Scopus, CINAHL, PsycINFO, and LILACS, using controlled descriptors, synonyms, and keywords combined with Boolean operators. All steps of this review were independently conducted by two researchers. The selected studies were classified by evidence hierarchy, and a generic quantitative tool was used for the assessment of the studies. RESULTS: A total of 473 studies were identified, of which 13 which met all the inclusion criteria were selected and analyzed. Of these studies, 61.5% (n = 8) had final scores equal to or greater than 70%, i.e., they were classified by this tool as being well-reported. The comparative analysis of international rare diseases demonstrates that public authorities' priorities and recommendations regarding this topic also permeate and apply to the Brazilian context. CONCLUSIONS: The evaluation and monitoring of public policies directed at rare disease patients are urgent and necessary to improve and implement such policies with less bureaucracy and more determination for this unique population that requires timely and high-quality care.

Epidemiological profile and clinical characteristics of 491 Brazilian patients with neurofibromatosis type 1.

BACKGROUND: Neurofibromatosis type 1 (NF1) is a chronic and progressive autosomal dominant genetic and sporadic disease characterized by cutaneous and neurological abnormalities. Plexiform neurofibroma (PN), a significant cause of clinical complications in NF-1, is a benign tumor of the peripheral nerve sheath that involves multiple nerve fascicles. Although there is an important number of patients who are affected by NF1 in Brazil, there is little data on the behavior of the disease in the national literature as well as in other low- and middle-income countries. METHODS: We performed a retrospective analysis of 491 patients with NF1 followed at two reference centers in Brazil. RESULTS: Approximately 38% of patients had PNs, resulting in reduced life quality. The median patient age with PNs was 30 years (range: 6 to 83 years). Head and neck, and extremity were the main affected locations with 35.8 and 30.6%, respectively. PNs were classified as asymptomatic in 25.1% of patients, while 52.5% presented symptomatic and inoperable tumors. The most common manifestations related to PNs were disfigurement and orthopedic involvement. Twenty patients developed neoplasms and ten (50%) presented with malignant peripheral nerve sheath tumors (MPNST). The prevalence of MPNST in our study was 2.9%. CONCLUSIONS: Patients with NF1 experience clinically significant morbidity, especially when it is associated with PN. Though there are many patients affected by NF1 in Brazil and other low- and middle-income countries, there is little data available in the corresponding literature. Our results are comparable to the previous results reported from higher-income countries and international registries.

Epidemiology of rare diseases in Brazil: protocol of the Brazilian Rare Diseases Network (RARAS-BRDN).

The Brazilian Policy of Comprehensive Care for People with Rare Diseases (BPCCPRD) was established by the Ministry of Health to reduce morbidity and mortality and improve the quality of life of people with rare diseases (RD). Several laboratory tests, most using molecular genetic technologies, have been incorporated by the Brazilian Public Health System, and 18 specialised centres have so far been established at university hospitals (UH) in the capitals of the Southern, Southeastern and Northeastern regions. However, whether the available human and technological resources in these services are appropriate and sufficient to achieve the goals of care established by the BPCCPRD is unknown. Despite great advances in diagnosis, especially due to new technologies and the recent structuring of clinical assessment of RD in Brazil, epidemiological data are lacking and when available, restricted to specific disorders. This position paper summarises the performance of a nationally representative survey on epidemiology, clinical status, and diagnostic and therapeutic resources employed for individuals with genetic and non-genetic RD in Brazil. The Brazilian Rare Disease Network (BRDN) is under development, comprising 40 institutions, including 18 UH, 17 Rare Diseases Reference Services and five Newborn Screening Reference Services. A retrospective study will be initially conducted, followed by a prospective study. The data collection instrument will use a standard protocol with sociodemographic data and clinical and diagnostic aspects according to international ontology. This great collaborative network is the first initiative of a large epidemiological data collection of RD in Latin America, and the results will increase the knowledge of RD in Brazil and help health managers to improve national public policy on RD in Brazil.

Implementação de um programa de mentoring para estudantes de graduação em saúde: a experiência da FMRP-USP / Implementation of a mentoring program for undergraduate health students: the experience of FMRP-USP

Resumo: Introdução: Discussões acerca da importância de proporcionar uma formação integral a estudantes do ensino superior têm sido ampliadas. Para além da aquisição de competências técnicas, ressalta-se a importância do desenvolvimento relacional, de atitudes e valores sustentados em princípios éticos. No campo da formação em saúde, cuidar dos futuros cuidadores pode ser uma forma de atingir tais objetivos. Programas de mentoria configuram uma relação de ajuda em que uma pessoa mais experiente na área de formação acolhe, orienta e auxilia um grupo de ingressantes na mesma área, contribuindo para o desenvolvimento acadêmico, pessoal e social. Relato de experiência: Este trabalho relata a implementação, o desenvolvimento e a manutenção de um programa de mentoring para cursos da área da saúde em uma instituição pública de ensino superior, sob coordenação do Centro de Apoio Educacional e Psicológico. Foi iniciado por meio de um projeto-piloto com o curso de Medicina e oferecido posteriormente aos demais cursos da unidade de ensino. Caracteriza-se como atividade extracurricular, de caráter voluntário, oferecida no primeiro semestre aos estudantes ingressantes. Os encontros são conduzidos por mentores, auxiliados por estudantes veteranos, os peers. Discussão: São destacados fatores que contribuíram para maior ou menor sensibilização e compreensão dos objetivos do programa, adesão dos participantes e manutenção dos grupos. O programa recebeu ajustes e modificações alinhados às próprias transformações ocorridas no centro responsável por sua coordenação, com o investimento em atividades coletivas de promoção de bem-estar e qualidade de vida. Conclusão: Programas de mentoria são intervenções importantes para acolhimento e suporte a estudantes durante a formação universitária. Podem apresentar desafios em sua implementação e manutenção, necessitando de coordenação e acompanhamentos constantes, em diálogo com todos os envolvidos em sua realização.

Abstract: Introduction: Discussions on the importance of providing comprehensive education to students in higher education have been broadened. In addition to the acquisition of technical skills, the importance of relational development, attitudes and values based on ethical principles is emphasized. In the field of health education, taking care of future caregivers can be a way to achieve these goals. Mentoring programs constitute a help relationship in which a person with more experience in the field of training welcomes, guides and assists a group of newcomers in the same area, contributing to academic, personal and social development. Experience report: This work reports on the implementation, development and maintenance of a Mentoring Program for students from undergraduate health courses of a public higher education institution, under the coordination of its educational and psychological support center. It was initiated through a pilot project with medical students, and later offered to students from six other undergraduate health courses of the teaching unit. It is characterized as a voluntary, extracurricular activity, offered in the first semester to incoming students. The meetings are conducted by mentors, assisted by veteran students, the peers. Discussion: The study highlights factors that contributed to a greater or lesser awareness and understanding of the program's objectives, participation and the maintenance of groups. The program was adjusted and modified in line with the changes that took place at the center responsible for its coordination, with investment in collective activities to promote well-being and quality of life. Conclusion: Mentoring programs are important interventions for welcoming and supporting students during their undergraduate training. They can present challenges in their implementation and maintenance, requiring coordination and constant monitoring, in dialogue with all those involved in their implementation.

First description of ultramutated endometrial cancer caused by germline loss-of-function and somatic exonuclease domain mutations in POLE gene.

Endometrial cancer (EC) harboring heterozygous POLE proofreading inactivating mutations (POLE-exo*) is associated with an increased number of somatic mutations that result in a distinctive anti-tumor immune response. However, the consequences of such POLE mutations in the context of the missing wild-type allele have not yet been described in endometrial tumors. A 72-year-old woman harboring a germline monoallelic frameshift mutation (p.Pro269fsTer26) in POLE was diagnosed with an EC having a somatic heterozygous mutation in the exonuclease domain of POLE (S459F). Targeted gene sequencing revealed an ultramutated phenotype (381 mutations/Mb) in the tumor and a 2-fold excess of mutations on the DNA leading strand. Additionally, we observed a mutational signature similar to the COSMIC signature 10, a higher mutation rate in this tumor than in endometrial tumors with heterozygous POLE-exo*, and an increased number of T lymphocytes. This is the first report of an ultramutated EC harboring a somatic POLE-exo* mutation in association with a germline loss-of-function mutation in this gene. The absence of a wild type POLE allele led to a particularly high mutational burden.

Lynch syndrome identification in a Brazilian cohort of endometrial cancer screened by a universal approach.

OBJECTIVE: To report the frequency of Lynch syndrome (LS) in a cohort of patients from Southeast Brazil bearing endometrial cancer (EC), using a tumor screening universal approach. METHODS: A total of 242 endometrial carcinomas were screened by immunohistochemistry (IHC) and microsatellite instability (MSI) for detection of DNA mismatch repair deficiency (dMMR). MLH1 methylation was assessed to identify sporadic cases. Patients with dMMR tumors were recruited for germline variant analysis by next-generation sequencing of the MLH1, MSH2, MSH6, PMS2, and EPCAM genes. RESULTS: Ninety-three out of 242 tumors (38.5%) were classified as dMMR based on MSI and IHC results. Of these, 54 cases were selected for germline analysis, and 37/54 (68.5%) were available for sequencing. Ten patients (10/37, 27%) harbored germline pathogenic or likely pathogenic variants, most of them in the MSH6 gene (4/10, 40%). Seven variants of uncertain significance were found. Eight novel germline variants were identified. The LS prevalence in our cohort was of at least 4.1%. LS patients presented lower mean age at cancer diagnosis compared with patients diagnosed with sporadic EC. Individuals with dMMR tumors, without germline pathogenic variants detected in LS-genes ("Lynch-like" syndrome), had an intermediate mean age at cancer diagnosis between LS and sporadic cases. CONCLUSION: This is the first report of the LS prevalence in EC screened by a universal approach in Brazil. Our findings contribute to a better understanding of the mutational landscape of this syndrome in Brazil, which is relevant for improved identification, genetic counseling, prevention and control of cancer in LS.

Germline variants in DNA repair genes associated with hereditary breast and ovarian cancer syndrome: analysis of a 21 gene panel in the Brazilian population.

BACKGROUND: The Hereditary Breast and Ovarian Cancer Syndrome (HBOC) occurs in families with a history of breast/ovarian cancer, presenting an autosomal dominant inheritance pattern. BRCA1 and BRCA2 are high penetrance genes associated with an increased risk of up to 20-fold for breast and ovarian cancer. However, only 20-30% of HBOC cases present pathogenic variants in those genes, and other DNA repair genes have emerged as increasing the risk for HBOC. In Brazil, variants in ATM, ATR, CHEK2, MLH1, MSH2, MSH6, POLQ, PTEN, and TP53 genes have been reported in up to 7.35% of the studied cases. Here we screened and characterized variants in 21 DNA repair genes in HBOC patients. METHODS: We systematically analyzed 708 amplicons encompassing the coding and flanking regions of 21 genes related to DNA repair pathways (ABRAXAS1, ATM, ATR, BARD1, BRCA1, BRCA2, BRIP1, CDH1, CHEK2, MLH1, MRE11, MSH2, MSH6, NBN, PALB2, PMS2, PTEN, RAD50, RAD51, TP53 and UIMC1). A total of 95 individuals with HBOC syndrome clinical suspicion in Southeast Brazil were sequenced, and 25 samples were evaluated for insertions/deletions in BRCA1/BRCA2 genes. Identified variants were assessed in terms of population allele frequency and their functional effects were predicted through in silico algorithms. RESULTS: We identified 80 variants in 19 genes. About 23.4% of the patients presented pathogenic variants in BRCA1, BRCA2 and TP53, a frequency higher than that identified among previous studies in Brazil. We identified a novel variant in ATR, which was predicted as pathogenic by in silico tools. The association analysis revealed 13 missense variants in ABRAXAS1, BARD1, BRCA2, CHEK2, CDH1, MLH1, PALB2, and PMS2 genes, as significantly associated with increased risk to HBOC, and the patients carrying those variants did not present large insertions or deletions in BRCA1/BRCA2 genes. CONCLUSIONS: This study embodies the third report of a multi-gene analysis in the Brazilian population, and addresses the first report of many germline variants associated with HBOC in Brazil. Although further functional analyses are necessary to better characterize the contribution of those variants to the phenotype, these findings would improve the risk estimation and clinical follow-up of patients with HBOC clinical suspicion.

Molecular basis of familial adenomatous polyposis in the southeast of Brazil: identification of six novel mutations.

BACKGROUND: The goal of this study was to screen point mutations and deletions in APC and MUTYH genes in patients suspected of familial adenomatous polyposis (FAP) in a Brazilian cohort. METHODS: We used high-resolution melting, Sanger direct sequencing and multiplex ligation-dependent probe association (MLPA) assays to identify point mutations, and large genomic variations within the coding regions of APC and MUTYH genes. RESULTS: We identified 19 causative mutations in 40 Brazilian patients from 20 different families. Four novel mutations were identified in the APC gene and two in the MUTYH gene. We also found a high intra- and inter-familial diversity regarding extracolonic manifestations, and gastric polyps were the most common manifestation found in our cohort. CONCLUSION: We believe that the FAP mutational spectrum can be population-specific and screening FAP patients in different populations can improve pre-clinical diagnosis and improve clinical conduct.

Competency Profile in Genetics for Physicians in Brazil: A Proposal of the Brazilian Society of Medical Genetics and Genomics / Perfil de Competência em Genética para Médicos do Brasil: uma Proposta da Sociedade Brasileira de Genética Médica e Genômica

ABSTRACT Training in genetics is fundamental to understanding the biological aspects of the health-disease binomial. Moreover, with the change in the epidemiological profile, genetically determined disorders have become more relevant as a public health concern. Thus, managing these disorders in an ethical and diligent manner, both in patients and in their families, and considering the logic and policies of the Brazilian Unified Health System (SUS), has become a desirable competency for all physicians, impacting on their undergraduate training. Viewing this issue as relevant, the Brazilian Society of Medical Genetics and Genomics (SBGM) defined the desirable competencies in genetics for Brazilian physicians, tied to the public policies related to medical genetics in Brazil. This paper is a theoretical essay that aims to contextualize and present the competency profile in Genetics for physicians proposed by the SBGM. The proficiency profile, presented and discussed in this essay, was structured based on four essential competencies: (1) to recognise the necessity for continuing education, regularly examining one's own clinical competency, identifying learning gaps and the advances of genetics and of genomics over time; (2) to identify individuals that present or can develop a genetic disorder and know how and when to refer the patient to a specialist in medical genetics; (3) to manage patients with previously diagnosed genetic disorders and/or birth defects, employing established clinical guidelines in the scope of their professional role; and (4) to promote and stimulate clinical and education practices aimed at preventing genetic disorders and birth defects. The knowledge, skills and attitudes required for attaining these four competencies were identified. Therefore, a competency-based theoretical reference is presented to support the teaching of genetics during medical training. It is proposed that this essential competency profile in genetics should be adopted in all Brazilian medical schools with the purpose of training physicians better prepared for the current demands of the SUS. Furthermore, this competency profile can support continuing professional education actions in the area of Genetics, in order to qualify SUS staff in relation to genetic disorders and birth defects.

RESUMO Educação em genética é fundamental para o entendimento dos aspectos biológicos do binômio saúde-doença. Além disso, com a mudança do perfil epidemiológico, as doenças com determinantes genéticos tornaram-se mais relevantes como problema de saúde pública. Assim, manejar estas doenças, tanto em pacientes como em suas famílias, de forma ética, diligente e considerando a lógica e as políticas do Sistema Único de Saúde (SUS), passa a ser competência desejável para todos os médicos, impactando sua formação na graduação. Entendendo esta questão como absolutamente relevante, a Sociedade Brasileira de Genética Médica e Genômica (SBGM) definiu as competências desejáveis em genética para os médicos do Brasil, articuladas às políticas públicas relacionadas à área existentes no País. Este artigo é um ensaio teórico que objetiva contextualizar e apresentar o perfil de competência em genética para médicos proposto pela SBGM. O perfil de competência, apresentado e discutido neste ensaio, foi estruturado com base em quatro competências essenciais: (a) reconhecer a necessidade de educação continuada, examinando regularmente a sua própria competência clínica; (b) identificar indivíduos que apresentem ou possam desenvolver uma doença genética e saber como e quando encaminhá-los para aconselhamento genético; (c) manejar pacientes com doenças genéticas e/ou defeitos congênitos no âmbito da sua atuação profissional; (d) promover e estimular práticas clínicas e de educação em saúde, objetivando a prevenção de doenças genéticas e defeitos congênitos. Conhecimentos, habilidades e atitudes necessários para alcançar essas quatro competências foram elencados. Dessa forma, é apresentado um referencial teórico, baseado em competências, para apoiar o ensino da genética durante a graduação em Medicina. Defende-se a adoção deste perfil de competência mínimo em genética em todas as escolas médicas brasileiras com a finalidade de formar um médico mais adequado às atuais demandas do SUS. Adicionalmente, esse perfil de competência pode subsidiar ações de educação profissional permanente na área da genética, de forma a capacitar o recurso humano do SUS em relação às doenças genéticas e aos defeitos congênitos.

Contribution of SLC26A4 to the molecular diagnosis of nonsyndromic prelingual sensorineural hearing loss in a Brazilian cohort.

OBJECTIVE: Hereditary hearing loss (HL) is the most common sensorineural disorder in humans. Besides mutations in GJB2 and GJB6 genes, pathogenic variants in the SLC26A4 gene have been reported as a cause of hereditary HL due to its role in the physiology of the inner ear. In this research we wanted to investigate the prevalence of mutations in SLC26A4 in Brazilian patients with nonsyndromic prelingual sensorineural HL. We applied the high-resolution melting technique to screen 88 DNA samples from unrelated deaf individuals that were previously screened for GJB2, GJB6 and MT-RNR1 mutations. RESULTS: The frequency of mutations in the SLC26A4 gene was 28.4%. Two novel mutations were found: p.Ile254Val and p.Asn382Lys. The mutation c.-66C>G (rs17154282) in the promoter region of SLC26A4, was the most frequent mutation found and was significantly associated with nonsyndromic prelingual sensorineural HL. After mutations in the GJB2, GJB6 and mitochondrial genes, SLC26A4 mutations are considered the next most common cause of hereditary HL in Brazilian as well as in other populations, which corroborates with our data. Furthermore, we suggest the inclusion of the SCL26A4 gene in the investigation of hereditary HL since there was an increase in the frequency of the mutations found, up to 22.7%.

Genetic education, knowledge and experiences between nurses and physicians in primary care in Brazil: A cross-sectional study.

Recent advances in genomics and related technologies have the potential to improve health care throughout the world. In this cross-sectional study, we examine genetics education, knowledge, and genetics-related experiences among the nurses and physicians who provide primary care in a Brazilian city. Fifty-four healthcare professionals from family health units participated in the study (response rate: 90%). Data were collected using a structured 36-item questionnaire divided into five axes: sociodemographic data and academic background; genetics education; genetics knowledge; genetics-related experiences in family practice; and knowledge regarding the National Policy for Comprehensive Care in Clinical Genetics in the Unified Health System. Although most participants (85.2%) acknowledged receiving some genetic content during their undergraduate education, the majority (77.8%) advised that they did not feel prepared to deliver genomics-based health care in primary care. The results suggest that nurses and physicians often lack the knowledge to provide genomics-based health care in primary care. Therefore, continuing education in genetics/genomics should be provided to primary healthcare professionals in order to enhance family practice and compliance with national policies.

I Fórum Paulista de Serviços de Apoio ao Estudante de Medicina — Forsa Paulista — “A Carta de Marília” / I Forum of Paulista Medical Student Support Services — Forsa Paulista — “The Letter of Marília”

RESUMO No dia 12 de maio de 2016, estiveram reunidos na cidade de Marília, no I Fórum de Serviços de Apoio aos Estudantes de Medicina (Forsa), realizado durante o 10° Congresso Paulista de Educação Médica (CPEM), representantes de serviços de apoio discente, bem como docentes e estudantes de Medicina, a fim de discutir e elencar estratégias de fortalecimento dos serviços de apoio à saúde discente, estritamente necessárias no contexto violento em que se inserem as escolas médicas. Foi criado um documento, denominado “A Carta de Marília”. Em 13 de outubro de 2016, esse documento foi referendado pelo XI Fórum Cobem dos Serviços de Apoio (Forsa Cobem) durante o 54º Congresso Brasileiro de Educação Médica na cidade de Brasília.

ABSTRACT On May 12, 2016 the first Forum for Support Services for Medical Students (Forsa) held in the city of Marilia during the 10th Paulista Congress of Medical Education (CPEM), gathered representatives of student support services, as well as teachers and medical students in order to discuss and rank strategies to enhance the services to support student health, strictly necessary in the violent setting in which medical schools operate. A document was created and named “The Letter of Marilia.” On October 13, 2016, this document was endorsed by the XI COBEM Forum for Support Services (FORSA COBEM) during the 54th Brazilian Medical Education Congress in Brasília.

Self-reported cancer family history is a useful tool for identification of individuals at risk of hereditary cancer predisposition syndrome at primary care centers in middle-income settings: a longitudinal study.

Analysis of cancer family history (CFH) offers a low-cost genetic tool to identify familial cancer predisposition. In middle-income settings, the scarcity of individual records and database-linked records hinders the assessment of self-reported CFH consistency as an indicator of familial cancer predisposition. We used self-reported CFH to identify those families at risk for hereditary cancer syndromes in community-based primary care centers of a low-income Brazilian area. We also evaluated the consistency of the information collected by reassessing CFH five years later. We interviewed 390 families and constructed their pedigrees for genetic cancer risk assessment. We found 125 families affected by cancer, 35.2% with moderate to high risk of familial susceptibility to cancer, a number that represents a relatively high prevalence of potential hereditary cancer syndromes in the overall study sample. Upon reassessment of CFH in 14/20 families that were previously identified as having at least one first-degree and one second-degree relative affected by cancer, and presented moderate to high risk for developing cancer, 90% of initial pedigrees were confirmed. These results demonstrate the reliability of self-reports as a means of early identification of healthy individuals at risk, encouraging the wider use of this method in low- and middle-income primary care settings.

Recurrent Mutations in the Basic Domain of TWIST2 Cause Ablepharon Macrostomia and Barber-Say Syndromes.

Ablepharon macrostomia syndrome (AMS) and Barber-Say syndrome (BSS) are rare congenital ectodermal dysplasias characterized by similar clinical features. To establish the genetic basis of AMS and BSS, we performed extensive clinical phenotyping, whole exome and candidate gene sequencing, and functional validations. We identified a recurrent de novo mutation in TWIST2 in seven independent AMS-affected families, as well as another recurrent de novo mutation affecting the same amino acid in ten independent BSS-affected families. Moreover, a genotype-phenotype correlation was observed, because the two syndromes differed based solely upon the nature of the substituting amino acid: a lysine at TWIST2 residue 75 resulted in AMS, whereas a glutamine or alanine yielded BSS. TWIST2 encodes a basic helix-loop-helix transcription factor that regulates the development of mesenchymal tissues. All identified mutations fell in the basic domain of TWIST2 and altered the DNA-binding pattern of Flag-TWIST2 in HeLa cells. Comparison of wild-type and mutant TWIST2 expressed in zebrafish identified abnormal developmental phenotypes and widespread transcriptome changes. Our results suggest that autosomal-dominant TWIST2 mutations cause AMS or BSS by inducing protean effects on the transcription factor's DNA binding.

Genotype-Phenotype Correlations in CYP1B1-Associated Primary Congenital Glaucoma Patients Representing Two Large Cohorts from India and Brazil.

BACKGROUND: Primary congenital glaucoma (PCG), occurs due to the developmental defects in the trabecular meshwork and anterior chamber angle in children. PCG exhibits genetic heterogeneity and the CYP1B1 gene has been widely implicated worldwide. Despite the diverse mutation spectra, the clinical implications of these mutations are yet unclear. The present study attempted to delineate the clinical profile of PCG in the background of CYP1B1 mutations from a large cohort of 901 subjects from India (n=601) and Brazil (n=300). METHODS: Genotype-phenotype correlations was undertaken on clinically well characterized PCG cases from India (n=301) and Brazil (n=150) to assess the contributions of CYP1B1 mutation on a set of demographic and clinical parameters. The demographic (gender, and history of consanguinity) and quantitative clinical (presenting intraocular pressure [IOP] and corneal diameter [CD]) parameters were considered as binary and continuous variables, respectively, for PCG patients in the background of the overall mutation spectra and also with respect to the prevalent mutations in India (R368H) and Brazil (4340delG). All these variables were fitted in a multivariate logistic regression model using the Akaike Information Criterion (AIC) to estimate the adjusted odds ratio (OR) using the R software (version 2.14.1). RESULTS: The overall mutation spectrum were similar across the Indian and Brazilian PCG cases, despite significantly higher number of homozygous mutations in the former (p=0.024) and compound heterozygous mutations in the later (p=0.012). A wide allelic heterogeneity was observed and only 6 mutations were infrequently shared between these two populations. The adjusted ORs for the binary (demographic) and continuous (clinical) variables did not indicate any susceptibility to the observed mutations (p>0.05). CONCLUSIONS: The present study demonstrated a lack of genotype-phenotype correlation of the demographic and clinical traits to CYP1B1 mutations in PCG at presentation. However, the susceptibility of these mutations to the long-term progression of these traits are yet to be deciphered.

The breast cancer immunophenotype of TP53-p.R337H carriers is different from that observed among other pathogenic TP53 mutation carriers.

Germline TP53 mutations are associated with Li-Fraumeni syndrome, an autosomal dominant disorder characterized by a predisposition to multiple early-onset cancers including breast cancer (BC), the most prevalent tumor among women. The majority of germline TP53 mutations are clustered within the DNA-binding domain of the gene, disrupting the structure and function of the protein. A specific germline mutation in the tetramerization domain of p53, p.R337H, was reported at a high frequency in Southern and Southeastern Brazil. This mutation appears to result in a more subtle defect in the protein, which becomes functionally deficient only under particular conditions. Recent studies show that the BC phenotype in TP53 mutation carriers is often HER2 positive (63-83%). Considering that the immunophenotype of BC among p.R337H carriers has not been reported, we reviewed immunohistochemistry data of 66 p.R337H carriers in comparison with 12 patients with other non-functional TP53 germline mutation. Although 75% of carriers of these mutations showed significant HER2 overexpression (3+), corroborating previous studies, only 22.7% of p.R337H patients had BC overexpressing HER2. These results reinforce the notion that different germline mutations in TP53 may predispose to BC via different mechanisms.