A endogamia explicaria a elevada prevalência de deficiências em populações do Nordeste brasileiro?

Communicating the diagnosis of spinal muscular atrophy in endogamous vs. non-endogamous regions

INTRODUCTION

The high prevalence of endogamy, or inbreeding, in northeastern Brazil, is due to historical and cultural factors, with large families living in cities far from the coast and subject to low socioeconomic and infrastructure levels. This breeding practice results in low genetic variability with an increased prevalence of rare autosomal recessive and neurodegenerative diseases, such as spinal muscular atrophy (SMA).

OBJECTIVE

Understanding the impact of communicating the diagnosis of SMA on the mental health of patients and their families and the differences between the Northeast (endogamous region) and the other regions of Brazil (non-endogamous ones).

METHODS

Cross-sectional study obtained through a structured questionnaire about the moment of receiving the SMA diagnosis, containing the Impact of Event Scale-Revised.

RESULTS AND DISCUSSION

The sample consisted of 100 volunteers from all regions of Brazil, 47 patients diagnosed with SMA and 53 family members present at the time of the diagnosis. There was a predominance of females (83%) and homogeneity between the groups for the variables gender, age, color, education, religion, and SMA subtype (1, 2, 3, and 4). The Northeast region, representing 43% of the sample, despite being less economically favored, showed greater satisfaction with medical care and inclusion in health services, with less self-reported psychological trauma and fewer signs of post-traumatic stress disorder (PTSD) related to the moment of receiving the diagnosis. The non-endogamous regions, in turn, reported the presence of strong waves of emotion, sleep problems, feelings of irritability, anger, and the presence of bad thoughts related to this situation.

CONCLUSION

The feeling of inclusion in health services and satisfaction with medical care in the endogamous region had a positive impact on the mental health of those involved, reducing psychological trauma and signs of PTSD arising from the communication of the SMA diagnosis.

Analyzing Inbreeding and Estimating Its Related Deficiencies in Northeastern Brazil

This cross-sectional study aimed to observe number of marriages between relatives in São Francisco Valley municipalities and correlations between degrees of kinship and susceptibility to genetic diseases. Three hundred and nine (309) consanguineous couples were interviewed in five municipalities. The data were analyzed using SPSS (version 22), Chi-square testing, and the generalized estimating equation (GEE). In Pariconha-AL for first cousins, the results revealed significantly higher numbers of disabled children than for third cousins (p < 0.05). Of these, the prevalence for physical disability was significant (χ2 = 19.203, df = 4, p = 0.001). In the cities of Glória-BA (χ2 = 11.652, df = 3, p = 0.020) and OlhoD'água do Casado-AL (χ2 = 8.123, df = 4, p = 0.044), physical disabilities were also significantly higher in children from unions of first-degree cousins than for other degrees of kinship. Visual impairment was more significant in first-degree cousins in Glória-BA (χ2 = 14.206, df = 3 p = 0.007); yet among third-degree cousins, visual impairment in the municipality of Santa Brígida-BA was more prevalent (χ2 = 6.416, df = 2 p = 0.040). Inbreeding, as revealed in the evaluated cities, reinforces the hypothesis for developing genetic diseases.

A large family with CYLD cutaneous syndrome: medical genetics at the community level

Germline mutations in the cylindromatosis gene (CYLD) are associated with a rare autosomal dominant disease known as CYLD cutaneous syndrome (CCS). Patients present multiple neoplasms originating from skin appendages. Here, we investigated the main clinical and molecular features of a large family with CCS having lived in a small Brazilian town for 6 generations, making its prevalence significantly high. We observed a predominance of the disease among males and a wide phenotypic variation. A high frequency of basal cell carcinomas among affected people was found. The mutation c.2806C>T, p.Arg936* in the CYLD gene was detected in all patients. In this work, a geographical cluster of CCS was found, which raised some community genetics issues related not only to the high prevalence of a rare disease in a limited area but also to the strong social stigma associated with the disease.

IDENTIFICATION OF MUTATIONS IN THE PAH GENE IN PKU PATIENTS IN THE STATE OF MATO GROSSO

Objective:

To identify phenylalanine hydroxylase (PAH) mutations in patients with phenylketonuria (PKU) from the Newborn Screening Service in Mato Grosso, Midwest Brazil.

Methods:

This is a cross-sectional descriptive study. The sample consisted of 19 PKU patients diagnosed by newborn screening. Molecular analysis: DNA extraction using the “salting-out” method. Detection of IVS10nt-11G>A, V388M, R261Q, R261X, R252W, and R408W mutations by the restriction fragment length polymorphism (RFLP) technique.

Results:

Two mutant alleles were identified in four patients (21.1%), one allele in five patients (26.2%), and none in the remaining ten patients (52.6%). A total of 13/38 alleles were detected, corresponding to 34.2% of the PAH alleles present. The most prevalent variant was V388M (13.2% of the alleles), followed by R261Q (10.1%) and IVS10nt-11G>A (7.9%). Three variants (R261X, R252W, and R408W) were not found. The most frequent mutation types were: missense mutation in eight alleles (18.4%) and splicing in four alleles (10.5%). The model proposed by Guldberg to determine a genotype/phenotype correlation was applied to four classical PKU patients with two identified mutations. In three of them, the predicted moderate/moderate or moderate PKU phenotype did not coincide with the actual diagnosis. The prediction coincided with the diagnosis of one classic PKU patient. The estimated incidence of PKU for Mato Grosso, Brazil, was 1:33,342 live births from 2003 to 2015.

Conclusion:

The only mutations found in the analyzed samples were the IVS10nt-11G>A, V388M, and R261Q. The genotype/phenotype correlation only occurred in four (5.3%) patients.

A population-based study of inter-generational attitudes towards consanguineous marriages in north-eastern Brazil

The aim of this cross-sectional study was to investigate beliefs, attitudes and reproductive behaviours in relation to consanguinity in a population living in the backlands of north-eastern Brazil. Data were collected by face-to-face interview from 147 high school students aged 13-20 years and from 532 elderly individuals aged 60 years and over from Brejo dos Santos in the state of Paraíba in 2017. The frequency of consanguineous marriage was found to have increased over the generations, being 15.9% in the parents of the elderly participants, 17.1% in the elderly participants themselves and 20.5% in their descendants. Although 258 (50.9%) of the elderly interviewees opposed consanguineous union, 341 (65.3%) would approve of the marriage of their children with relatives. Both the young (n=108 or 78.3%) and elderly (n=398 or 80.4%) interviewees believed that consanguineous marriages were no more durable than non-consanguineous marriages (p=0.578). Additionally, 408 (82.4%) of the elderly individuals and 108 (80.6%) of the students recognized that spouses in consanguineous unions experience conflicts, just like other couples do (p=0.625). In both groups, the majority of the participants did not believe that consanguinity increased the risk of having children with disabilities. The regression of the two continuous variables 'age' and 'positive attitudes score' showed a significant correlation, suggesting that younger individuals are more susceptible to the influence of cultural factors contributing to consanguinity, such as the opinions of their parents and grandparents. The belief that consanguineous unions are more durable showed a significant difference between elderly individuals in consanguineous and non-consanguineous unions (p=0.001); the former were 2.42 more likely to believe that marriages between relatives contributes to marriage durability.

Inclusion and exclusion in the globalisation of genomics; the case of rare genetic disease in Brazil

Within the context of a globalising agenda for genetic research where ‘global health’ is increasingly seen as necessarily informed by and having to account for genomics, the focus on rare genetic diseases is becoming prominent. Drawing from ethnographic research carried out separately by both authors in Brazil, this paper examines how an emerging focus on two different arenas of rare genetic disease, cancer genetics and a class of degenerative neurological diseases known as Ataxias, is subject to and a product of the dynamics of inclusion and exclusion as this concerns participation in research and access to health care. It examines how in these different cases ‘rarenesss’ has been diversely situated and differently politicised and how clinicians, patients and their families grapple with the slippery boundaries between research, rights to health and the limits of care, therapy or prevention. It illustrates how attention to rare genetic disease in Brazil emerges at the intersection of a particular history of genetic research and public health infrastructure, densely complicated feedback loops between clinical care and research, patient mobilisation around the ‘judicialisation’ of health and recent state legislation regarding rare disease in Brazil. It highlights the relevance of local configurations in the way rare genetic disease is being made relevant for and by different communities.

Prevalência autorreferida de deficiência no Brasil, segundo a Pesquisa Nacional de Saúde, 2013

Resumo Objetivo descrever a prevalência autorreferida das deficiências intelectual, física, auditiva e visual, segundo variáveis sociodemográficas, grau de limitação e frequência de uso de serviço de reabilitação. Métodos Dados provenientes da Pesquisa Nacional de Saúde, inquérito populacional. Foram calculadas as prevalências autorreferidas de deficiência física, mental, visual e auditiva e seus intervalos de confiança de 95%, estratificados por sexo, faixa etária, raça/cor, para Brasil, local de residência e Grandes Regiões. Resultados a prevalência de deficiência autorreferida no país foi de 6,2% (12,4 milhões de pessoas). A prevalência de deficiência física foi de 1,3%, maior em homens, em indivíduos com 60 anos ou mais na região Nordeste. A deficiência visual foi mais prevalente (3,6%), aumentou com a idade, assim como deficiência auditiva. A deficiência adquirida foi maior em relação à de nascença (exceto intelectual). Menor grau de limitação foi observado entre os que referiram deficiência visual e o uso de serviços de saúde foi menos frequente. Conclusão há necessidade de ampliar o acesso às ações de promoção, diagnóstico e tratamento precoce, bem como o fortalecer políticas públicas direcionadas a esta população.

As causas da deficiência física em municípios do nordeste brasileiro e estimativa de custos de serviços especializados

As populações do nordeste brasileiro possuem elevadas taxas de endogamia e deficiências. Neste trabalho, foi realizado um estudo epidemiológico transversal com método do informante para descrever doenças genéticas e as adquiridas que causam deficiências físicas em oito municípios da Paraíba e estimar os custos por serviços especializados de fisioterapia e aquisição de equipamentos de tecnologia assistiva. De uma população de 48.499 habitantes, 338 pessoas foram triadas e 123 (0,34%) realizaram avaliação clínico-genética e funcional por uma equipe multidisciplinar de especialistas. Fatores genéticos foram responsáveis por 58,5% das deficiências, sendo encontrados alguns agrupamentos de afecções prevalentes nas populações amostradas: amiotrofia espinal progressiva, ataxia espinocerebelar, distrofia muscular e síndrome Spoan. A descrição do perfil socioeconômico e das demandas por serviços de reabilitação e tecnologia assistiva apontam para necessidade de estabelecimento de políticas públicas específicas para essas comunidades.

Increased prevalence of inherited neuromuscular disorders due to endogamy in Northeast Brazil: the need of community genetics services

The aim of this study was to investigate the prevalence of inherited neuromuscular disorders (NMDs) in eight communities in Northeast (NE) Brazil in which there was an elevated rate of inbreeding. A cross-sectional epidemiological study, using the key informant (KI) approach, was performed to estimate the prevalence of NMD among the 48,499 individuals living in these eight communities, located in the backlands of the Paraíba State. Twenty-seven individuals fulfilled the diagnostic criteria for inherited NMD, which means that 1 out of 1,796 inhabitants of this highly consanguineous population was affected by NMD. This is twofold higher than that observed in previous studies in general population and was probably due to a combination of genetic drift and inbreeding. Public policies should be implemented to offer genetics services in high-risk communities.