Abstract Background The Brazilian Policy for Comprehensive Care for People with Rare Diseases was implemented in 2014; however, national epidemiological data on rare diseases (RDs) are scarce and mainly focused on specific disorders. To address this gap, University Hospitals, Reference Services for Neonatal Screening, and Reference Services for Rare Diseases, all of which are public health institutions, established the Brazilian Rare Diseases Network (RARAS) in 2020. The objective of this study was to perform a comprehensive nationwide epidemiological investigation of individuals with RDs in Brazil. This retrospective survey collected data from patients receiving care in 34 healthcare facilities affiliated with RARAS in 2018 and 2019. Results The survey included 12,530 participants with a median age of 15.0 years, with women representing 50.5% of the cohort. Classification according to skin color demonstrated that 5044 (47.4%) participants were admixed. Most had a confirmed diagnosis (63.2%), with a predominance of phenylketonuria (PKU), cystic fibrosis (CF), and acromegaly. Common clinical manifestations included global developmental delay and seizures. The average duration of the diagnostic odyssey was 5.4 years (± 7.9 years). Among the confirmed diagnoses, 52.2% were etiological (biochemical: 42.5%; molecular: 30.9%), while 47.8% were clinical. Prenatal diagnoses accounted for 1.2%. Familial recurrence and consanguinity rates were 21.6% and 6.4%, respectively. Mainstay treatments included drug therapy (55.0%) and rehabilitation (15.6%). The Public Health System funded most diagnoses (84.2%) and treatments (86.7%). Hospitalizations were reported in 44.5% of cases, and the mortality rate was 1.5%, primarily due to motor neuron disease and CF. Conclusion This study marks a pioneering national-level data collection effort for rare diseases in Brazil, offering novel insights to advance the understanding, management, and resource allocation for RDs. It unveils an average diagnostic odyssey of 5.4 years and a higher prevalence of PKU and CF, possibly associated with the specialized services network, which included newborn screening services.

INTRODUCTION: Phenylketonuria (PKU) is an inborn error of amino acid metabolism, with autosomal recessive inheritance. In non-treated patients, clinical signs may appear in the first months of life as hypotonia and neuropsychomotor development delay, in addition to seizures, irritability and a characteristic odor. In Brazil, PKU was one of the first genetic disorders to be included in neonatal screening, with the aim of starting early dietary treatment. OBJECTIVES: To present an overview of PKU in Brazil, using data from the Brazilian Rare Diseases Network (RARAS). MATERIALS AND METHODS: Data from individuals with a confirmed diagnosis of PKU assisted at the centers were included in this study. Cases were collected in the retrospective (2018-2019) and prospective (2022 to May 2024) survey. Data was collected and extracted from the REDCap. RESULTS: 717 individuals were included, 68.9% were female, with a mean age of 16.0 (±11.8) years at the time of data collection. Neonatal screening was responsible for 74.9% of diagnoses, while symptomatic diagnosis represented 22.5%. The largest paying source for diagnoses was the Unified Health System (SUS, 95.6%). The Southeast region had the highest number of diagnoses, with 65.2%, followed by the Northeast region, with 16.3%. CONCLUSION: Although included in neonatal screening since 2000, our data show that almost 1/4 of patients (22.5%) were diagnosed after presenting symptoms. Although the largest source of payment for diagnoses is the SUS, there is great regional inequality. Furthermore, this study corroborates the importance of diagnosis in the neonatal period to begin treatment in the first days of life. The majority of diagnoses in this registry were made through the Brazilian Unified Health System (SUS), highlighting the crucial role of the public healthcare system in neonatal screening and the diagnosis of rare diseases.

INTRODUÇÃO: Cerca de 1% dos nascidos vivos apresentam cardiopatias congênitas, sejam elas sindrômicas ou isoladas. Elas podem ser classificadas fenotípicamente em morfológicas, fisiológicas, detectadas em testes cardíacos e vasculares. OBJETIVOS: Determinar a prevalência de alterações cardiovasculares e descrever os fenótipos anormais mais prevalentes do sistema cardiovascular em um serviço de genética médica. METODOLOGIA: Foi realizada uma subanálise de participantes incluídos na Rede Nacional de Doenças Raras. Descreveu-se os diagnósticos de uma coorte de pacientes pediátricos atendidos no Hospital da Criança Santo Antônio da Santa Casa de Misericórdia de Porto Alegre - um hospital pediátrico de alta complexidade na região sul do Brasil - entre janeiro e maio de 2024. Deste universo, foram identificados os pacientes com acometimento cardiovascular e, para padronização, discriminaram-se os fenótipos relatados segundo o terceiro nível do Human Phenotype Ontology (disponível em https://www.ebi.ac.uk/ols4). Nos casos em que a redundância da classificação implicou na coexistência de mais de um descritor cardiovascular no quarto nível, todas as opções relevantes foram analisadas. Redundâncias que envolviam termos não relacionados ao sistema cardiovascular foram excluídas. RESULTADOS: Dos 135 participantes, 41 (30,3%) apresentaram algum acometimento cardiovascular - totalizando 62 alterações cardiovasculares e 75 descritores em 4º nível. A população estudada era majoritariamente masculina (24 indivíduos; 58,5%), com mediana de idade de 0 anos e média de 3,1 anos. Considerando os fenótipos encontrados em 3º nível, destacam-se como as mais comuns: alterações morfológicas do coração (46,6%), alterações morfológicas vasculares (25,3%) e alterações morfológicas das valvas (8%). Entre as alterações morfológicas do coração, verificou-se 9 casos de defeitos de septo atrial; das alterações vasculares 5 casos de Tetralogia de Fallot e 4 de coarctação aórtica. Ademais, 11 pacientes (26,8%) tinham diagnóstico etiológico definido; 8 (19,5%) com diagnóstico suspeito; 2 pacientes foram submetidos a cirurgia, e nenhum óbito foi verificado. CONCLUSÃO: Lesões cardíacas são prevalentes em pacientes em acompanhamento genético, especialmente as estruturais. Como limitações, destaca-se que este estudo é unicêntrico e incluiu pacientes majoritariamente pediátricos (apenas 2,4% tinham idade igual ou maior a 18 anos - média de 21 anos); assim, é interessante que análises semelhantes sejam replicadas. O número limitado de diagnósticos etiológicos na coorte em estudo pode ser explicado pela alta prevalência de cardiopatias não sindrômicas (70% dos casos) e multifatoriais.