The importance of geographic and sociodemographic aspects in the characterization of mucopolysaccharidoses: a case series from Ceará state (Northeast Brazil).

Geographic and sociodemographic aspects may influence the natural history and epidemiology of mucopolysaccharidoses (MPS). The main objective in this work was to evaluate the clinical, molecular, and geographic profile of MPS in a population from Ceará (Northeast Brazil). For this, we have performed a descriptive cross-sectional study based on clinical evaluation, interviews with patients and/or family members, and review of medical records of 76 MPS patients. MPS II was the most common type, with the most affected individuals presenting missense pathogenic variants. Patients with MPS I proved to be the most severe clinical phenotype, presenting the first symptoms (mean: 7.1 months; SD = 4.5) and being diagnosed earlier (2.2 years; SD = 2.1) in comparison with the other types. In addition, we have shown that 13 individuals with MPS VI were born of consanguineous marriages in small, nearby cities, in a place where geographical isolation, consanguinity, and clusters of genetic diseases were previously reported. Ten of these individuals (at least, seven different families) presented a rare pathogenic variant in the ARSB gene, c.1143-8T > G in homozygosity, previously reported only among Iberian and South American patients. The results presented here provide a comprehensive picture of MPS in an important state of the Brazilian Northeast, a region that concentrates many risk factors for rare genetic diseases, such as endogamy, inbreeding, and reproductive isolation. We discuss the possible evolutionary processes and biosocial dynamics that can help to explain this finding in terms of population medical genetics and public health.

An invincible memory: what surname analysis tells us about history, health and population medical genetics in the Brazilian Northeast.

Several studies have shown that the Brazilian Northeast is a region with high rates of inbreeding as well as a high incidence of autosomal recessive diseases. The elaboration of public health policies focused on the epidemiological surveillance of congenital anomalies and rare genetic diseases in this region is urgently needed. However, the vast territory, socio-demographic heterogeneity, economic difficulties and low number of professionals with expertise in medical genetics make strategic planning a challenging task. Surnames can be compared to a genetic system with multiple neutral alleles and allow some approximation of population structure. Here, surname analysis of more than 37 million people was combined with health and socio-demographic indicators covering all 1794 municipalities of the nine states of the region. The data distribution showed a heterogeneous spatial pattern (Global Moran Index, GMI = 0.58; p < 0.001), with higher isonymy rates in the east of the region and the highest rates in the Quilombo dos Palmares region - the largest conglomerate of escaped slaves in Latin America. A positive correlation was found between the isonymy index and the frequency of live births with congenital anomalies (r = 0.268; p < 0.001), and the two indicators were spatially correlated (GMI = 0.50; p < 0.001). With this approach, quantitative information on the genetic structure of the Brazilian Northeast population was obtained, which may represent an economical and useful tool for decision-making in the medical field.

Decifrando o "mistério dos gêmeos": vinte anos de pesquisa em Cândido Godói, Rio Grande do Sul / Solving the "twins mystery": twenty years of research in Cândido Godói, Rio Grande do Sul state

Cândido Godói (CG) é um pequeno município brasileiro localizado no noroeste do Rio Grande do Sul e é conhecido como "Cidade dos Gêmeos" devido à alta taxa de nascimentos gemelares na região. Diante de um fato tão notável, muitas explicações foram sugeridas. Entre estas teorias, a que mais recebeu atenção da mídia, mesmo sem base científica, foi a de que a gemelaridade seria fruto de experimentos de um médico nazista alemão foragido após a Segunda Guerra Mundial. A convite da própria comunidade de CG, nosso grupo de pesquisa trabalha para resolver este mistério desde 1994, analisando diferentes fatores possivelmente relacionados, em especial suas características genéticas. Aqui, nós sumarizamos os principais resultados obtidos em mais de duas décadas de pesquisa, com foco nas particularidades do processo de comunicação dos resultados, aspectos éticos e como os achados científicos naquela comunidade contribuem não apenas com a resolução de um mistério histórico e local, mas também com o estudo de outras questões, como a reprodução humana e as bases biológicas da gemelaridade. (AU)

Cândido Godói (CG) is a small town located in the northwest region of Rio Grande do Sul state which is known as "Town of Twins" because of the high rate of twin births. Many explanations have been suggested for such a noteworthy fact. The theory that has received most attention from the press, despite a lack of scientific evidence, was that twinning would result from experiments conducted by a Nazi German physician who had been a fugitive after World War II. Invited by the local community, our research team has been dedicated to solving this mystery since 1994 by analyzing different possibly related factors, especially genetic characteristics. In this paper, we summarize the main results obtained in more than two decades of research, focusing on the particular communication process of the results, ethical aspects, and how the scientific findings in that community have contributed not only to the resolution of a historical and localized mystery, but also with the study of other issues such as human reproduction and biological basis of the twinning process. (AU)

Genealogical data in population medical genetics: Field guidelines.

This is a guide for fieldwork in Population Medical Genetics research projects. Data collection, handling, and analysis from large pedigrees require the use of specific tools and methods not widely familiar to human geneticists, unfortunately leading to ineffective graphic pedigrees. Initially, the objective of the pedigree must be decided, and the available information sources need to be identified and validated. Data collection and recording by the tabulated method is advocated, and the involved techniques are presented. Genealogical and personal information are the two main components of pedigree data. While the latter is unique to each investigation project, the former is solely represented by gametic links between persons. The triad of a given pedigree member and its two parents constitutes the building unit of a genealogy. Likewise, three ID numbers representing those three elements of the triad is the record field required for any pedigree analysis. Pedigree construction, as well as pedigree and population data analysis, varies according to the pre-established objectives, the existing information, and the available resources.

Atenção em genética médica no sus: a experiência de um município de médio porte / Attention in medical genetics in the brazilian health system: the experience of a medium-sized municipality

Realizou-se estudo descritivo e exploratório da experiência em município de médio porte da implantação de ações na área da Genética, conjugando a análise dos documentos oficiais e de um questionário aplicado a 43 profissionais de nível superior da Estratégia Saúde da Família. Os dados obtidos foram analisados buscando obter respostas sobre como e por que foram realizadas determinadas estratégias de atenção à saúde na área da Genética Clínica e Comunitária. Tais ações foram classificadas em "educação permanente", "vigilância em saúde" e "ampliação do acesso à assistência". Os resultados revelaram que ainda é necessário estender as ações de educação permanente na área para profissionais da atenção primária, possibilitando assim promover a efetivação dessa porta de entrada do Sistema Único de Saúde para a área da Genética e o acesso a um cuidado integral em saúde.

We conducted a descriptive study on the experience of implementation of actions in the area of genetics in a medium-sized municipality, combining the analysis of official documents and a questionnaire administered to 43 university level professionals of the Family Health Strategy. The data were analyzed looking for answers about how and why certain health care strategies in the area of clinical and community genetics were performed. Such actions were classified as "continuing education", "health surveillance" and "enhanced access to care". The results showed that it is still necessary to extend the actions of continuing education in genetics for primary care professionals, promoting this gateway to the SUS also to the area of genetics, in order to allow full access to comprehensive health care.