Genetic analysis of osteogenesis imperfecta in a large Brazilian cohort.

INTRODUCTION: Osteogenesis imperfecta (OI) is a genetically and clinically heterogeneous disorder caused by disruption of type I collagen synthesis. Previous Brazilian molecular OI studies have been restricted to case reports or small cohorts. The Brazilian OI Network (BOIN) is a multicenter study collecting clinical OI treatment data from five reference centers in three regions of Brazil. OBJECTIVE: To describe the molecular analysis of a large cohort of OI registered at BOIN. METHODS: Targeted next-generation sequencing (NGS) was performed at a centralized laboratory with the Ion Torrent platform, covering 99.6 % of the coding regions of 18 OI-associated genes. Clinical information was obtained from a clinical database. RESULTS: We included 156 subjects in the molecular analyses. Variants were detected in 121 subjects: 65 (53.7 %) in COL1A1, 42 (34.7 %) in COL1A2, 2 (1.7 %) in IFITM5, one (0.8 %) in CRTAP, three (2.5 %) in P3H1, two (1.7 %) in PPIB, four (3.3 %) FKBP10, one (0.8 %) in SERPINH1, and one (0.8 %) in TMEM38B. Ninety-one distinct variants were identified, of which 26 were novel. Of the 107 variants identified in COL1A1 and COL1A2, 24.5 % cause mild OI, while the remaining 75.5 % cause moderate, severe, or lethal OI, of which 49.3 % are glycine to serine substitutions. A single variant in FKBP10 (c.179A>C; p.Gln60Pro) was found in three unrelated and non-consanguineous participants living in the same geographic area in Northeast Brazil, suggesting a possible founder effect. CONCLUSION: Consistent with the literature, 88.4 % of the subjects had a variant in the COL1A1 and COL1A2 genes, with 10 % inherited in an autosomal recessive manner. Notably, one variant in FKBP10 with a potential founder effect requires further investigation. Data from this large cohort improves our understanding of genotype-phenotype correlations for OI in Brazil.

Study of IRF6 and 8q24 region in non-syndromic oral clefts in the Brazilian population.

OBJECTIVES: We investigated the association between non-syndromic oral cleft and variants in IRF6 (rs2235371 and rs642961) and 8q24 region (rs987525) according to the ancestry contribution of the Brazilian population. SUBJECTS AND METHODS: Subjects with oral cleft (CL, CLP, or CP) and their parents were selected from different geographic regions of Brazil. Polymorphisms were genotyped using a TaqMan assay and genomic ancestry was estimated using a panel of 48 INDEL polymorphisms. RESULTS: A total of 259 probands were analyzed. A TDT detected overtransmission of the rs2235371 G allele (P = 0.0008) in the total sample. A significant association of this allele was also observed in CLP (P = 0.0343) and CLP + CL (P = 0.0027). IRF6 haplotype analysis showed that the G/A haplotype increased the risk for cleft in children (single dose: P = 0.0038, double dose: P = 0.0022) and in mothers (single dose: P = 0.0016). The rs987525 (8q24) also exhibited an association between the A allele and the CLP + CL group (P = 0.0462). These results were confirmed in the probands with European ancestry. CONCLUSIONS: The 8q24 region plays a role in CL/P and the IRF6 G/A haplotype (rs2235371/rs642961) increases the risk for oral cleft in the Brazilian population.

MSX1 gene and nonsyndromic oral clefts in a Southern Brazilian population.

Nonsyndromic oral clefts (NSOC) are the most common craniofacial birth defects in humans. The etiology of NSOC is complex, involving both genetic and environmental factors. Several genes that play a role in cellular proliferation, differentiation, and apoptosis have been associated with clefting. For example, variations in the homeobox gene family member MSX1, including a CA repeat located within its single intron, may play a role in clefting. The aim of this study was to investigate the association between MSX1 CA repeat polymorphism and NSOC in a Southern Brazilian population using a case-parent triad design. We studied 182 nuclear families with NSOC recruited from the Hospital de Clínicas de Porto Alegre in Southern Brazil. The polymorphic region was amplified by the polymerase chain reaction and analyzed by using an automated sequencer. Among the 182 families studied, four different alleles were observed, at frequencies of 0.057 (175 bp), 0.169 (173 bp), 0.096 (171 bp) and 0.67 (169 bp). A transmission disequilibrium test with a family-based association test (FBAT) software program was used for analysis. FBAT analysis showed overtransmission of the 169 bp allele in NSOC (P=0.0005). These results suggest that the CA repeat polymorphism of the MSX1 gene may play a role in risk of NSOC in populations from Southern Brazil.

MSX1 gene and nonsyndromic oral clefts in a Southern Brazilian population

Nonsyndromic oral clefts (NSOC) are the most common craniofacial birth defects in humans. The etiology of NSOC is complex, involving both genetic and environmental factors. Several genes that play a role in cellular proliferation, differentiation, and apoptosis have been associated with clefting. For example, variations in the homeobox gene family member MSX1, including a CA repeat located within its single intron, may play a role in clefting. The aim of this study was to investigate the association between MSX1 CA repeat polymorphism and NSOC in a Southern Brazilian population using a case-parent triad design. We studied 182 nuclear families with NSOC recruited from the Hospital de Clínicas de Porto Alegre in Southern Brazil. The polymorphic region was amplified by the polymerase chain reaction and analyzed by using an automated sequencer. Among the 182 families studied, four different alleles were observed, at frequencies of 0.057 (175 bp), 0.169 (173 bp), 0.096 (171 bp) and 0.67 (169 bp). A transmission disequilibrium test with a family-based association test (FBAT) software program was used for analysis. FBAT analysis showed overtransmission of the 169 bp allele in NSOC (P=0.0005). These results suggest that the CA repeat polymorphism of the MSX1 gene may play a role in risk of NSOC in populations from Southern Brazil.

Hantavirus pulmonary syndrome in the State of São Paulo, Brazil, 1993-1998.

Between 1993 and 1998, 10 cases of clinical hantavirus infection were diagnosed in Brazil. Hantavirus-specific IgM, or positive immunohistochemical analysis for hantavirus antigen, or positive reverse transcription-polymerase chain reaction results for hantavirus RNA were used to confirm nine of these cases; eight were hantavirus pulmonary syndrome (HPS), and one was mild hantavirus disease. The remaining clinical case of hantavirus infection was fatal, and no tissue was available to confirm the diagnosis. During the first 7 months of 1998, five fatal HPS cases caused by a Sin Nombre-like virus were reported from three different regions in the State of São Paulo, Brazil: two in March (Presidente Prudente Region), two in May (Ribeirão Preto Region), and one in July (Itapecerica da Serra Region). Epidemiologic, ecologic, and serologic surveys were conducted among case contacts, area residents, and captured rodents in five locations within the State of São Paulo in June of 1998. Six (4.8%) of 125 case contacts and six (5.2%) of 116 area residents had IgG antibody to Sin Nombre virus (SNV) antigen. No case contacts had a history of HPS-compatible illness, and only one area resident reported a previous acute respiratory illness. A total of 403 rodents were captured during 9 nights of trapping (1969 trap nights). All 27 rodents that were found to be positive for IgG antibody to SNV antigen were captured in crop border and extensively deforested agricultural areas where four of the 1998 HPS case-patients had recently worked. The IgG antibody prevalence data for rodents suggest that Bolomys lasiurus and perhaps Akodon sp. are potential hantavirus reservoirs in this state of Brazil.

Phenotypic and molecular analyses of yellow fever 17DD vaccine viruses associated with serious adverse events in Brazil.

The yellow fever (YF) 17D virus is one of the most successful vaccines developed to data. Its use has been estimated to be over 400 million doses with an excellent record of safety. In the past 3 years, yellow fever vaccination was intensified in Brazil in response to higher risk of urban outbreaks of the disease. Two fatal adverse events temporally associated with YF vaccination were reported. Both cases had features similar to yellow fever disease, including hepatitis and multiorgan failure. Two different lots of YF 17DD virus vaccine were administered to the affected patients and also to hundreds of thousands of other individuals without any other reported serious adverse events. The lots were prepared from the secondary seed, which has been in continuous use since 1984. Nucleotide sequencing revealed minor variations at some nucleotide positions between the secondary seed lot virus and the virus isolates from patients; these differences were not consistent across the isolates, represented differences in the relative amount of each nucleotide in a heterogeneous position, and did not result in amino acid substitutions. Inoculation of rhesus monkeys with the viruses isolated from the two patients by the intracerebral (ic) or intrahepatic (ih) route caused minimal viremia and no clinical signs of infection or alterations in laboratory markers. Central nervous system histological scores of rhesus monkeys inoculated ic were within the expected range, and there were no histopathological lesions in animals inoculated ih. Altogether, these results demonstrated the genetic stability and attenuated phenotype of the viruses that caused fatal illness in the two patients. Therefore, the fatal adverse events experienced by the vaccinees are related to individual, genetically determined host factors that regulate cellular susceptibility to yellow fever virus. Such increased susceptibility, resulting in clinically overt disease expression, appears to be extremely rare.

Genetic investigation of novel hantaviruses causing fatal HPS in Brazil.

Although hantavirus pulmonary syndrome (HPS) was discovered in North America in 1993, more recent investigations have shown that the disease is a much larger problem in South America, where a greater number of cases and HPS-associated viruses have now been detected. Here we describe the genetic investigation of three fatal HPS cases from Brazil, including a 1995 case in Castelo dos Sonhos (CAS) in the state of Mato Grosso and two 1996 cases in the counties of Araraquara (ARA) and Franca (FRA), in the state of São Paulo. Reverse transcription-polymerase chain reaction (RT-PCR) products representing fragments of the hantavirus N, G1, and G2 coding regions were amplified from patient acute-phase serum samples, and the nucleotide (nt) sequences (394, 259, and 139 nt, respectively) revealed high deduced amino acid sequence identity between ARA and FRA viruses (99.2%, 96.5%, and 100%, respectively). However, amino acid differences of up to 14.0% were observed when ARA and FRA virus sequences were compared with those of the geographically more distant CAS virus. Analysis of a 643-nt N coding region and a 1734-nt predominantly G2-encoding region of ARA and CAS virus genomes confirmed that these Brazilian viruses were distinct and monophyletic with previously characterized Argentinean hantaviruses, and suggested that Laguna Negra (LN) virus from Paraguay was ancestral to both the Brazilian and Argentinean viruses. The phylogenetic tree based on the N coding fragment also placed LN in a separate clade with Rio Mamore virus from Bolivia. At the amino acid level, ARA and CAS viruses appeared more closely related to the Argentinean viruses than they were to each other. Similarly, analysis of the diagnostic 139-nt G2 fragment showed that the Juquitiba virus detected in a 1993 fatal HPS case close to São Paulo city, Brazil was closer to Argentinean viruses than to ARA or CAS viruses. These data indicate that at least three different hantavirus genetic lineages are associated with Brazilian HPS cases.

Human disease caused by an arbovirus closely related to Ilheus virus: report of five cases.

We report five cases of human disease caused by arbovirus in 5 patients from the State of São Paulo, Brazil, residing in the municipalities of Osasco, Atibaia, Guarujá, and the capital São Paulo, respectively. One of the patients resides in São Luis, capital of the State of Maranhão. The sites of infection probably were the states of Paraná and Goiás, both in cave regions, the State of Amazonas, and Rondônia in two cases. Laboratory tests for malaria were negative and 1 patient showed a positive serum reaction for leptospirosis. Serum samples from the acute and convalescent phases were tested by hemagglutination inhibition, complement fixation, and neutralization in mice. Acute phase samples were inoculated into suckling mice by the intracerebral route. A close antigenic relationship was observed between the five agents isolated and the flavivirus Ilheus. Serologic tests demonstrated the absence of antibodies in all samples from the 5 patients during convalescence and even for more than 1 year after infection in 1 of them.

Jungle yellow fever: clinical and laboratorial studies emphasizing viremia on a human case.

The authors report the clinical, laboratorial and epidemiological aspects of a human case of jungle yellow fever. The patient suffered from fever, chills, sweating, headaches, backaches, myalgia, epigastric pains, nausea, vomiting, diarrhea and prostration. He was unvaccinated and had been working in areas where cases of jungle yellow fever had been confirmed. Investigations concerning the yellow fever virus were performed. Blood samples were collected on several days in the course of the illness. Three of these samples (those obtained on days 5, 7 and 10) were inoculated into suckling mice in attempt to isolate virus and to titrate the viremia level. Serological surveys were carried out by using the IgM Antibodies Capture Enzyme Linked Immunosorbent Assay (MAC-ELISA), Complement Fixation (CF), Hemagglutination Inhibition (HI) and Neutralization (N) tests. The yellow fever virus, recovered from the two first samples and the virus titration, showed high level of viremia. After that, specific antibodies appeared in all samples. The interval between the end of the viremia and the appearance of the antibodies was associated with the worsening of clinical symptoms, including bleeding of the mucous membrane. One must be aware of the risk of having a urban epidemics in areas where Aedes aegypti is found in high infestation indexes.

Surveillance of arbovirus infections in the Atlantic Forest Region, State of São Paulo, Brazil. I. Detection of hemagglutination-inhibiting antibodies in wild birds between 1978 and 1990.

We report data related to arbovirus antibodies detected in wild birds periodically captured from January 1978 to December 1990 in the counties of Salesópolis (Casa Grande Station), Itapetininga and Ribeira Valley, considering the different capture environments. Plasmas were examined using hemagglutination-inhibition (HI) tests. Only monotypic reactions were considered, except for two heterotypic reactions in which a significant difference in titer was observed for a determined virus of the same antigenic group. Among a total of 39,911 birds, 269 birds (0.7%) belonging to 66 species and 22 families were found to have a monotypic reaction for Eastern equine encephalitis (EEE), Venezuelan equine encephalitis (VEE), Western equine encephalitis (WEE), Ilheus (ILH), Rocio (ROC), St. Louis encephalitis (SLE), SP An 71686, or Caraparu (CAR) viruses. Analysis of the data provided information of epidemiologic interest with respect to these agents. Birds with positive serology were distributed among different habitats, with a predominance of unforested habitats. The greatest diversity of positive reactions was observed among species which concentrate in culture fields.

New arenavirus isolated in Brazil.

A new arenavirus, called Sabiá, was isolated in Brazil from a fatal case of haemorrhagic fever initially thought to be yellow fever. Antigenic and molecular characterisation indicated that Sabiá virus is a new member of the Tacaribe complex. A laboratory technician working with the agent was also infected and developed a prolonged, non-fatal influenza-like illness. Sabiá virus is yet another arenavirus causing human disease in South America.

Esquema reduzido de vacinacao anti-rabica humana pre-exposicao e avaliacao de doses anuais de reforco. / Reduced schedule of human pre-exposure antirabies vaccination and evaluation of annual booster doses

Sao apresentados os resultados do emprego de esquema de vacinacao anti-rabica humana pre-exposicao, constituido de 3 doses de vacina tipo Fuenzalida-Palacios administradas a 165 pacientes em dias alternados, mais uma dose de reforco no 30o dia apos a dose inicial. Os titulos de anticorpos foram determinados por prova de soroneutralizacao em amostras de sangue colhidas antes, 30 e 40 dias apos administracao da primeira dose. Verificou-se que no 30o dia, 74,6% dos pacientes apresentaram anticorpos neutralizantes no soro,valor que se elevou a 98,1% no quadragesimo dia, o que mostra a eficacia do esquema em relacao a resposta imunitaria em tempo relativamente curto e a importancia da dose de reforco como estimulo a producao de anticorpos.Nos pacientes submetidos as doses anuais de reforco num periodo de 10 anos, verificou-se aumento gradual da presenca de anticorpos antes da administracao da dose de reforco subsequente, ate atingir valores de 100%. Face aos resultados obtidos foi sugerido que as doses de reforco sejam administradas a intervalos de tempo maiores e precedidas da titulagem de anticorpos a fim de se avaliar da necessidade ou nao de sua administracao