Suscetibilidade e resistência genética ao SARS-CoV-2 e COVID-19

Desde os primeiros momentos da pandemia de COVID-19 ficou evidente a variabilidade tanto de se infectar como de apresentar quadro clínico com diferente gravidade da doença. Epidemiologicamente se observou que homens mais velhos e com comorbidades seriam mais impactados pela doença. Dois anos e meio após o início da pandemia sabemos que a suscetibilidade e resistência a infecção pelo SARS-CoV-2 e gravidade da COVID-19 são dadas de forma muito complexa e multifatorial. O componente genético começa a ser desvendado, com importante implicação na compreensão da fisiopatologia da doença, em especial nos mecanismos de entrada do SARS-CoV-2 na célula humana, e nas defesas inatas do nosso sistema imunológico. Esta revisão descreve os principais loci, genes e alelos já implicados em formas raras desta interação vírus/hospedeiro, e ressalta a importância de que a elucidação das bases genéticas de formas raras pode ter para a compreensão mais ampla da maior pandemia dos últimos 100 anos. From the first moments of the COVID-19 pandemic, the variability of both becoming infected and presenting different degrees of disease severity became evident. Epidemiologically it was observed that older men and those with comorbidities would be more impacted by the disease. Two and a half years after the beginning of the pandemic, it is already known that susceptibility and resistance to infection by SARS-CoV-2 and COVID-19 are given in a very complex and multifactorial way. The genetic component is beginning to be unraveled, with important implications for understanding the pathophysiology of the disease, especially in the mechanisms of SARS-CoV-2 entry into the human cell, and the innate defenses of our immune system. This review describes the key loci, genes, and alleles already implicated in rare forms of this virus/host interaction, and highlights the importance of rare forms for a broader understanding of the most important pandemic of the past 100 years

Clinical and epidemiological study of orofacial clefts

Abstract Objective: Cleft lip with or without cleft palate (CL±P) or cleft palate (CP) are groups of malformations named orofacial clefts (OC), which are the second leading cause of birth defects. This study aimed to analyze clinical and epidemiological features of Brazilian patients with OC, studying cases treated in the reference center of the state of Paraná (PR). Methods: 2,356 charts were reviewed and 1,838 were evaluated by the same clinical geneticist. Data were collected in the reference center, and compared with those of the Health Department of the state of Paraná. Clinical characteristics, presence of other anomalies, and birth prevalence were evaluated. Results: 389 (21.2%) patients had CP, 437 (23.8%) had cleft lip (CL), and 1,012 (55%) had cleft lip and palate (CLP). Syndromic OC were identified in 15.3% of patients, 10.4% of patients with CL±P, and 33.9% of patients with CP. Common additional anomalies were: central nervous system, limbs, cardiovascular, and musculoskeletal defects. The number of syndromic cases was lower when clinical evaluation was performed by other medical specialists when compared to that of the clinical geneticist. Birth prevalence was 1/1,010 live births. Lack of notification with the national birth registry was observed in 49.9% of CL±P. The present data suggests a decrease of 18.52% in the prevalence of non-syndromic OC after folic acid fortification in Brazil. (23,8%) apresentaram fissura labial (FL) e 1.012 (55%) apresentaram fissura labiopalatina (FLP). As FO sindrômicas foram identificadas em 15,3% dos pacientes, 10,4% dos pacientes com FL ± P, e 33,9% dos pacientes com FP. Anomalias comuns adicionais foram: sistema nervoso central, membros, sistema cardiovascular e sistema musculoesqueléti-co. O número de casos sindrômicos foi menor nos centros em que a avaliação clínica foi realizada por outros especialistas, em comparação aos locais em que ela foi realizada por um geneticista clínico. A prevalência de nascimentos foi de 1/1.010 nascidos vivos. A ausência de notificação junto ao cartório de registro civil foi observada em 49,9% dos casos de FL ± P. No Brasil, nossos dados sugerem uma redução de 18,52% na prevalência de FO não sindrômicas após a fortificação com ácido fólico. Conclusão: Um melhor entendimento dos aspectos clínicos e epidemiológicos das FO é fundamental para melhorar a compreensão de sua patogênese, promover estratégias de prevenção e promover orientações com relação a cuidados clínicos, com a presença de geneticistas clínicos na equipe multidisciplinar para tratamento de FO, por exemplo

Tremor in X-linked recessive spinal and bulbar muscular atrophy (Kennedy's disease)

OBJECTIVE: To study tremor in patients with X-linked recessive spinobulbar muscular atrophy or Kennedy's disease. METHODS: Ten patients (from 7 families) with a genetic diagnosis of Kennedy's disease were screened for the presence of tremor using a standardized clinical protocol and followed up at a neurology outpatient clinic. All index patients were genotyped and showed an expanded allele in the androgen receptor gene. RESULTS: Mean patient age was 37.6 years and mean number of CAG repeats 47 (44-53). Tremor was present in 8 (80%) patients and was predominantly postural hand tremor. Alcohol responsiveness was detected in 7 (88%) patients with tremor, who all responded well to treatment with a β-blocker (propranolol). CONCLUSION: Tremor is a common feature in patients with Kennedy's disease and has characteristics similar to those of essential tremor

Displasia diastrófica: diagnóstico pré-natal e revisão da literatura

CONTEXT Diastrophic dysplasia is a type of osteochondrodysplasia caused by homozygous mutation in the gene DTDST (diastrophic dysplasia sulfate transporter gene). Abnormalities occurring particularly in the skeletal and cartilaginous system are typical of the disease, which has an incidence of 1 in 100,000 live births. CASE REPORT The case of a pregnant woman, without any consanguineous relationship with her husband, whose fetus was diagnosed with skeletal dysplasia based on ultrasound findings and DNA tests, is described. An obstetric ultrasound scan produced in the 16th week of gestation revealed characteristics that guided the clinical diagnosis. Prominent among these characteristics were rhizomelia of the lower and upper limbs (shortening of the proximal portions) and mesomelia (shortening of the intermediate portions). Both upper limbs showed marked curvature, with the first finger of the upper limbs in abduction and clinodactyly of the fifth finger. Molecular analysis using the polymerase chain reaction (PCR) and gene sequencing detected mutations that had already been described in the literature for the gene DTDST, named c.862C > T and c.2147_2148insCT. Therefore, the fetus was a compound heterozygote, carrying two different mutations. CONCLUSIONS Prenatal diagnosis of this condition allowed a more realistic interpretation of the prognosis, and of the couple's reproductive future. This case report shows the contribution of molecular genetics towards the prenatal diagnosis, for which there are few descriptions in the literature.CONTEXTO A displasia diastrófica é uma osteocondrodisplasia causada por mutação homozigótica no gene DTDST (diastrophic dysplasia sulfate transporter gene). As alterações, principalmente nos sistemas esquelético e cartilaginoso, são típicas dessa doença, que tem uma incidência de 1 em 100.000 nascidos vivos. RELATO DO CASO Descreve-se o caso de uma mulher gestante, sem relação consanguínea com o seu marido, cujo feto foi diagnosticado com displasia esquelética baseado na ultrassonografia e em testes de DNA. A ultrassonografia obstétrica, realizada na 16a semana, revelou características que guiaram o diagnóstico clínico. Entre elas, se destacam os membros inferiores e superiores com rizomelia (encurtamento das porções proximais) e mesomelia (encurtamento das porções intermediárias), ambos os membros superiores mostraram acentuada flexão, o primeiro dedo em abdução nas extremidades superiores e clinodactilia do quinto dedo. A análise molecular pela reação em cadeia da polimerase (PCR) e o sequenciamento gênico detectou mutações já descritas na literatura para o gene DTDST, chamado c.862C > T e c.2147_2148insCT. Portanto, o feto é um heterozigoto composto, carreando duas mutações diferentes. CONCLUSÕES O diagnóstico pré-natal dessa condição permite uma interpretação mais realista do prognóstico e do futuro reprodutivo do casal. Este relato de caso mostra a contribuição da genética molecular no diagnóstico pré-natal, com poucas descrições na literatura.Faculdades Integradas do Brasil (UniBrasil)Universidade Federal do Paraná (UFPR) Department of Gynecology and ObstetricsCentro de Diagnósticos (CEDUS)Pontifícia Universidade Católica do Paraná (PUCPR) Health and Biosciences School (ESB) Graduate Program in Health Science (PPGCS)Faculdades Integradas do Brasil (UniBrasil) Biomedicine CourseUniversidade Federal de São Paulo (UNIFESP) Department of ObstetricsUNIFESP, Department of ObstetricsSciEL

Spinocerebellar ataxias: genotype-phenotype correlations in 104 Brazilian families

OBJECTIVE: Spinocerebellar ataxias are neurodegenerative disorders involving the cerebellum and its connections. There are more than 30 distinct subtypes, 16 of which are associated with an identified gene. The aim of the current study was to evaluate a large group of patients from 104 Brazilian families with spinocerebellar ataxias. METHODS: We studied 150 patients from 104 families with spinocerebellar ataxias who had received molecular genetic testing for spinocerebellar ataxia types 1, 2, 3, 6, 7, 8, 10, 12, 17, and dentatorubral-pallidoluysian atrophy. A statistical analysis of the results was performed using basic descriptive statistics and the correlation coefficient (r), Student's t-test, chi-square test, and Yates' correction. The statistical significance level was established for p-value

Fibrose cística com dosagem de cloro no suor normal: relato de caso

A fibrose cística é uma doença genética usualmente diagnosticada através de teste anormal de dosagem de cloro no suor. Os autores descrevem o caso de uma paciente de 18 anos com bronquiectasias e infecção crônica por P. aeruginosa mas com dosagens de cloro no suor normais que evoluiu com rápido declínio da função pulmonar e piora clínica, a despeito do tratamento. Dada a forte suspeita de fibrose cística, realizou-se um teste de genotipagem amplo, evidenciando a presença de mutações deltaF508 e 3849+10kb C->;T, deste modo confirmando o diagnóstico de fibrose cística . Apesar da dosagem de cloro no suor ainda ser considerada o padrão ouro para o diagnóstico de fibrose cística , testes diagnósticos alternativos como genotipagem e medidas eletrofisiológicas devem ser empregados se há suspeita de fibrose cística , mesmo com níveis normais ou limítrofes de níveis de cloro no suor.Cystic fibrosis is a genetic disease usually diagnosed by abnormal sweat testing. We report a case of an 18-year-old female with bronchiectasis, chronic P. aeruginosa infection, and normal sweat chloride concentrations who experienced rapid decrease of lung function and clinical deterioration despite treatment. Given the high suspicion ofcystic fibrosis, broad genotyping testing was performed, showing a compound heterozygous with deltaF508 and 3849+10kb C->;T mutations, therefore confirming cystic fibrosis diagnosis. Although the sweat chloride test remains the gold standard for the diagnosis of cystic fibrosis, alternative diagnostic tests such as genotyping and electrophysiologic measurements must be performed if there is suspicion of cystic fibrosis, despite normal or borderline sweat chloride levels

Doença de Wilson no sul do Brasil: correlação genotípica-fenotípica\ud e a descrição de duas novas mutações no gene ATP7B

OBJECTIVE:\ud \ud Wilson's disease (WD) is an inborn error of metabolism caused by abnormalities of the copper-transporting protein encoding gene ATP7B. In this study, we examined ATP7B for mutations in a group of patients living in southern Brazil.\ud \ud METHODS:\ud \ud 36 WD subjects were studied and classified according to their clinical and epidemiological data. In 23 subjects the ATP7B gene was analyzed.\ud \ud RESULTS:\ud \ud Fourteen distinct mutations were detected in at least one of the alleles. The c.3207C>A substitution at exon 14 was the most common mutation (allelic frequency=37.1%) followed by the c.3402delC at exon 15 (allelic frequency=11.4%). The mutations c.2018-2030del13 at exon 7 and c.4093InsT at exon 20 are being reported for the first time.\ud \ud CONCLUSION:\ud \ud The c.3207C>A substitution at exon 14, was the most common mutation, with an allelic frequency of 37.1%. This mutation is the most common mutation described in Europe.OBJETIVO:\ud \ud A doença de Wilson (DW) é um erro inato do metabolismo causado por abnormalidades no gene ATP7B, que codifica uma proteína transportadora de cobre. Neste estudo, avaliamos as mutações do gene ATP7B em um grupo de pacientes do sul do Brasil.\ud \ud MÉTODOS:\ud \ud Foram estudados 36 pacientes com DW e classificados do ponto de vista clínico e epidemiológico. Em 23 pacientes, o gene ATP7B foi analisado.\ud \ud RESULTADOS:\ud \ud A substituição c.3207C>A no éxon 14 foi a mutação mais comum seguida pela mutação c.3402delC no éxon 15 . A mutação c.2018-2030del13 no éxon 7 e a c.4093InsT no éxon 20 são relatadas pela primeira vez na literatura.\ud \ud CONCLUSÃO:\ud \ud A mutação do gene ATP7B, com a substituição c.3207C>A no éxon 14 foi a mais frequente. Esta mutação é a mais comumente encontrada em pacientes europeus

Neuroradiological Findings in the Spinocerebellar Ataxias

Background: The spinocerebellar ataxias (SCAs) are a group of autosomal dominant degenerative diseases characterized by cerebellar ataxia. Classified according to gene discovery, specific features of the SCAs – clinical, laboratorial, and neuroradiological (NR) – can facilitate establishing the diagnosis. The purpose of this study was to review the particular NR abnormalities in the main SCAs. Methods: We conducted a literature search on this topic. Results: The main NR characteristics of brain imaging (magnetic resonance imaging or computerized tomography) in SCAs were: (1) pure cerebellar atrophy; (2) cerebellar atrophy with other findings (e.g., pontine, olivopontocerebellar, spinal, cortical, or subcortical atrophy; “hot cross bun sign”, and demyelinating lesions); (3) selective cerebellar atrophy; (4) no cerebellar atrophy. Discussion: The main NR abnormalities in the commonest SCAs, are not pathognomonic of any specific genotype, but can be helpful in limiting the diagnostic options. We are progressing to a better understanding of the SCAs, not only genetically, but also pathologically; NR is helpful in the challenge of diagnosing the specific genotype of SCA

Pure cerebellar ataxia due to bi-allelic PRDX3 variants including recurring p.Asp202Asn

Bi-allelic variants in peroxiredoxin 3 (PRDX3) have only recently been associated with autosomal recessive spinocerebellar ataxia characterized by early onset slowly progressive cerebellar ataxia, variably associated with hyperkinetic and hypokinetic features, accompanied by cerebellar atrophy and occasional olivary and brainstem involvement. Herein, we describe a further simplex case carrying a reported PRDX3 variant as well as two additional cases with novel variants. We report the first Brazilian patient with SCAR32, replicating the pathogenic status of a known variant. All presented cases from the Brazilian and Indian populations expand the phenotypic spectrum of the disease by displaying prominent neuroradiological findings. SCAR32, although rare, should be included in the differential diagnosis of sporadic or recessive childhood and adolescent-onset pure and complex cerebellar ataxia

Frequency of GAA-FGF14 Ataxia in a Large Cohort of Brazilian Patients With Unsolved Adult-Onset Cerebellar Ataxia

OBJECTIVES: Intronic FGF14 GAA repeat expansions have recently been found to be a common cause of hereditary ataxia (GAA-FGF14 ataxia; SCA27B). The global epidemiology and regional prevalence of this newly reported disorder remain to be established. In this study, we investigated the frequency of GAA-FGF14 ataxia in a large cohort of Brazilian patients with unsolved adult-onset ataxia. METHODS: We recruited 93 index patients with genetically unsolved adult-onset ataxia despite extensive genetic investigation and genotyped the FGF14 repeat locus. Patients were recruited across 4 different regions of Brazil. RESULTS: Of the 93 index patients, 8 (9%) carried an FGF14 (GAA)≥250 expansion. The expansion was also identified in 1 affected relative. Seven patients were of European descent, 1 was of African descent, and 1was of admixed American ancestry. One patient carrying a (GAA)376 expansion developed ataxia at age 28 years, confirming that GAA-FGF14 ataxia can occur before the age of 30 years. One patient displayed episodic symptoms, while none had downbeat nystagmus. Cerebellar atrophy was observed on brain MRI in 7 of 8 patients (87%). DISCUSSION: Our results suggest that GAA-FGF14 ataxia is a common cause of adult-onset ataxia in the Brazilian population, although larger studies are needed to fully define its epidemiology