Interaction among variants in the SLC gene family (SLC6A14, SLC26A9, SLC11A1, and SLC9A3) and CFTR mutations with clinical markers of cystic fibrosis.

BACKGROUND: Cystic fibrosis (CF) is due to dysfunction of the CFTR channel and function of this channel is, in turn, affected by modifier genes that can impact the clinical phenotype. In this context, we analyzed the interaction among rs3788766*SLC6A14, rs7512462*SLC26A9, rs17235416*SLC11A1, and rs17563161*SLC9A3 variants, CFTR mutations and 40 CF severity markers by the Multifactor Dimensionality Reduction (MDR) model. METHODS: A total of 164 patients with CF were included in the study. The variants in the modifier genes were identified by real-time PCR and the genotype of the CFTR gene in the diagnostic routine. Analysis of interaction between variants, CFTR mutations groupings and demographic, clinical and laboratory data were performed by the MDR. RESULTS: There were interaction between the rs3788766, rs7512462, rs17235416, and rs17563161 variants, and CFTR mutations with pancreatic insufficiency (PI), onset of digestive symptoms, and presence of mucoid Pseudomonas aeruginosa. Regarding PI, the interaction was observed for CFTR*rs17563161 (P-value = 0.015). Also, for onset of digestive symptoms the interaction was observed for CFTR*rs3788766*rs7512462*rs17235416*rs17563161 (P-value = 0.036). Considering the presence of mucoid P. aeruginosa, the interaction occurred for CFTR*rs3788766*rs7512462*rs17563161 (P-value = 0.035). CONCLUSION: Interaction between variants in the SLC family genes and the grouping for CFTR mutations were associated with PI, onset of digestive symptoms and mucoid P. aeruginosa, being important to determine one of the factors that may cause the diversity among the patients with CF.

Personalized or Precision Medicine? The Example of Cystic Fibrosis.

The advent of the knowledge on human genetics, by the identification of disease-associated variants, culminated in the understanding of human variability. With the genetic knowledge, the specificity of the clinical phenotype and the drug response of each individual were understood. Using the cystic fibrosis (CF) as an example, the new terms that emerged such as personalized medicine and precision medicine can be characterized. The genetic knowledge in CF is broad and the presence of a monogenic disease caused by mutations in the CFTR gene enables the phenotype-genotype association studies (including the response to drugs), considering the wide clinical and laboratory spectrum dependent on the mutual action of genotype, environment, and lifestyle. Regarding the CF disease, personalized medicine is the treatment directed at the symptoms, and this treatment is adjusted depending on the patient's phenotype. However, more recently, the term precision medicine began to be widely used, although its correct application and understanding are still vague and poorly characterized. In precision medicine, we understand the individual as a response to the interrelation between environment, lifestyle, and genetic factors, which enabled the advent of new therapeutic models, such as conventional drugs adjustment by individual patient dosage and drug type and response, development of new drugs (read through, broker, enhancer, stabilizer, and amplifier compounds), genome editing by homologous recombination, zinc finger nucleases, TALEN (transcription activator-like effector nuclease), CRISPR-Cas9 (clustered regularly interspaced short palindromic repeats-CRISPR-associated endonuclease 9), and gene therapy. Thus, we introduced the terms personalized medicine and precision medicine based on the CF.

TNF-alpha polymorphisms as a potential modifier gene in the cystic fibrosis.

Modifier genes, as the TNF-α gene, can modulate the cystic fibrosis (CF) severity. Thus, -238G>A and -308G>A polymorphisms of TNF-α gene were analyzed as modifiers of CF. In this context, the present study enrolled 49 CF patients (diagnosis performed by sweat test and complete CFTR screening). The -238G>A polymorphism analysis was performed by ARMS-PCR, and -308G>A, by PCR-RFLP. In our data, the -238G>A polymorphism was not associated with clinical variability. The AA genotype for -308G>A polymorphism was a risk factor for early gastrointestinal symptoms (OR=5.98, 95%CI=1.06-49.68) and protection for the first Pseudomonas aeruginosa (OR=0.05, 95%CI=0.0003-0.007). For the first P. aeruginosa, GA genotype was a risk factor (OR=10.2, 95%CI=1.86-84.09); for the same genotype, the diagnosis was made in minor time than the AA genotype (p=0.031). Considering the -308G>A polymorphism alleles, the G allele was a risk factor for early pulmonary symptoms (OR=3.81, 95%CI=1.13-12.97) and P. aeruginosa (OR=66.77, 95%CI=15.18-482.7); however, the same allele showed better transcutaneous oxygen saturation (OR=9.24, 95%CI=1.53-206.1). The A allele was a protective factor for early pulmonary symptoms (OR=12.26, 95%CI=0.08-0.89) and P. aeruginosa (OR=12.15, 95%CI=0002-0007), however, the same allele was a risk factor for worst transcutaneous oxygen saturation (OR=7.01, 95%CI=1.14-157.4). As conclusion, the -308G>A polymorphism of the TNF-α gene was associated with the CF severity.

Características epidemiológicas e genéticas associadas à gravidade da bronquiolite viral aguda pelo vírus sincicial respiratório / Epidemiological and genetic characteristics associated with the severity of acute viral bronchiolitis by respiratory syncytial virus

OBJETIVO: avaliar os fatores epidemiológicos e genéticos associados à gravidade da Bronquiolite Viral Aguda (BVA) pelo Vírus Sincicial Respiratório (VSR). FONTE DOS DADOS: foram utilizados descritores "bronchiolitis", "risk factor", "genetics" e "respiratory syncytial virus" e todas as combinações entre eles, nas bases de dados PubMed, SciELO e Lilacs publicados após o ano de 2000 e que incluíram indivíduos menores de dois anos de idade. SÍNTESE DOS DADOS: foram encontrados 1.259 artigos e lidos seus respectivos resumos. Destes foram selecionados 81 que avaliaram fatores de risco para a gravidade da BVA para leitura na íntegra, e foram incluídos os 60 estudos mais relevantes. Os fatores epidemiológicos associados com a gravidade da BVA pelo VSR foram: prematuridade, tabagismo passivo, baixa idade, ausência de aleitamento materno, doença pulmonar crônica, cardiopatia congênita, sexo masculino, etnia, coinfecção viral, baixo peso na admissão hospitalar, tabagismo materno na gestação, dermatite atópica, ventilação mecânica no período neonatal, antecedente materno de atopia e/ou asma na gestação, estação do nascimento, baixo nível socioeconômico, síndrome de Down, poluição ambiental, morar em altitude acima de 2.500 metros do nível do mar e parto cesariana. Em contrapartida, algumas crianças com BVA grave não apresentam nenhum desses fatores de risco. Neste sentido, estudos recentes têm verificado a influência de fatores genéticos relacionados à gravidade da BVA pelo VSR. Polimorfismos dos genes TLRs, RANTES, JUN, IFNA5, NOS2, CX3CR1, ILs e VDR têm-se mostrado associados com a evolução mais grave da BVA pelo VSR. CONCLUSÃO: a gravidade da BVA pelo VSR é um fenômeno dependente da interação entre variáveis epidemiológicas, ambientais e genéticas em seus diferentes graus de interação.

OBJECTIVE: to assess the epidemiological and genetic factors associated with severity of acute viral bronchiolitis (AVB) by respiratory syncytial virus (RSV). DATA SOURCE: the key words ''bronchiolitis'', ''risk factor'', ''genetics'' and ''respiratory syn-cytial virus'', and all combinations among them were used to perform a search in the PubMed,SciELO, and Lilacs databases, of articles published after the year 2000 that included individualsyounger than 2 years of age. DATA SYNTHESIS: a total of 1,259 articles were found, and their respective summaries were read. Of these, 81 were selected, which assessed risk factors for the severity of AVB, and were read in full; the 60 most relevant studies were included. The epidemiologic factors associated with AVB severity by RSV were prematurity, passive smoking, young age, lack of breastfeeding, chronic lung disease, congenital heart disease, male gender, ethnicity, viral coinfection, low weight at admission, maternal smoking during pregnancy, atopic dermatitis, mechanical ventilation in the neonatal period, maternal history of atopy and/or asthma during pregnancy, season of birth, low socioeconomic status, Down syndrome, environmental pollution, living at an altitude > 2,500 meters above sea level, and cesarean section birth. Conversely, some children with severe AVB did not present any of these risk factors. In this regard, recent studies have verified the influence of genetic factors on the severity of AVB by RSV. Polymorphisms of the TLRs, RANTES, JUN, IFNA5, NOS2, CX3CR1, ILs, and VDR genes have been shown to be associated with more severe evolution of AVB by RSV. CONCLUSION: the severity of AVB by RSV is a phenomenon that depends on the varying degrees of interaction among epidemiological, environmental, and genetic variables.

Measurements of CFTR-mediated Cl- secretion in human rectal biopsies constitute a robust biomarker for Cystic Fibrosis diagnosis and prognosis.

BACKGROUND: Cystic Fibrosis (CF) is caused by ∼1,900 mutations in the CF transmembrane conductance regulator (CFTR) gene encoding for a cAMP-regulated chloride (Cl(-)) channel expressed in several epithelia. Clinical features are dominated by respiratory symptoms, but there is variable organ involvement thus causing diagnostic dilemmas, especially for non-classic cases. METHODOLOGY/PRINCIPAL FINDINGS: To further establish measurement of CFTR function as a sensitive and robust biomarker for diagnosis and prognosis of CF, we herein assessed cholinergic and cAMP-CFTR-mediated Cl(-) secretion in 524 freshly excised rectal biopsies from 118 individuals, including patients with confirmed CF clinical diagnosis (n=51), individuals with clinical CF suspicion (n=49) and age-matched non-CF controls (n=18). Conclusive measurements were obtained for 96% of cases. Patients with "Classic CF", presenting earlier onset of symptoms, pancreatic insufficiency, severe lung disease and low Shwachman-Kulczycki scores were found to lack CFTR-mediated Cl(-) secretion (<5%). Individuals with milder CF disease presented residual CFTR-mediated Cl(-) secretion (10-57%) and non-CF controls show CFTR-mediated Cl(-) secretion ≥ 30-35% and data evidenced good correlations with various clinical parameters. Finally, comparison of these values with those in "CF suspicion" individuals allowed to confirm CF in 16/49 individuals (33%) and exclude it in 28/49 (57%). Statistical discriminant analyses showed that colonic measurements of CFTR-mediated Cl(-) secretion are the best discriminator among Classic/Non-Classic CF and non-CF groups. CONCLUSIONS/SIGNIFICANCE: Determination of CFTR-mediated Cl(-) secretion in rectal biopsies is demonstrated here to be a sensitive, reproducible and robust predictive biomarker for the diagnosis and prognosis of CF. The method also has very high potential for (pre-)clinical trials of CFTR-modulator therapies.

Polymorphisms in ADRB2 gene can modulate the response to bronchodilators and the severity of cystic fibrosis.

BACKGROUND: The most common cystic fibrosis (CF) manifestation is the progressive chronic obstructive pulmonary disease caused by deficiency, dysfunction, or absence of the CFTR (Cystic Fibrosis Transmembrane Regulator) protein on the apical surface of the cells in the respiratory tract. The use of bronchodilators (BD), and inhaled corticosteroids (IC) have been suggested for the management of airway inflammation in CF. The effectiveness of BD and IC have been verified, proven in laboratory and in the clinical treatment for asthma patients. However, in CF, the effectiveness of these drugs is controversial. The extent of asthma's response to BD depends on the presence of polymorphisms in the ADRB2 gene. In contrast, in CF, little is known about the response to the BD and the association of CF´s severity with the different polymorphisms in ADRB2 gene. In this context, our objective was to verify whether the Arg16Gly and Glu27Gln polymorphisms in ADRB2 gene are associated with severity and with the bronchodilator response in CF patients. METHOD: Cross-sectional study of 122 CF patients subjected to analysis of mutations in the CFTR gene, polymorphisms in ADRB2 gene, along with clinical and laboratorial characteristics of severity. RESULT: The Arg16Gly polymorphism in ADRB2 gene was associated with pancreatic insufficiency(p:0.009), Bhalla score(p:0.039), forced expiratory volume in the first second[FEV1(%)](p:0.003), forced expiratory flow between 25 and 75% of the forced vital capacity-FVC[FEF25-75(%)](p:0.008) and lower age at the first isolation of the Pseudomonas aeruginosa(p:0.012). The response to the BD spirometry was associated with clinical severity markers, FEV1(%)(p:0.011) and FEF25-75(%)(p:0.019), for the Arg16Gly polymorphism in the ADRB2 gene. The haplotype analysis showed association with the FEV1/FVC marker from the spirometry test, before and after using the BD, with higher values in the group with Gly/Gly and Glu/Glu, respectively, for the Arg16Gly and Gln27Glu polymorphisms. The analysis by MDR2.0 software, showed association with FEF25-75%; the response to Arg16Gly was respondent by 17.35% and Gln27Glu by 6.8% in variation found. CONCLUSION: There was an association between the Arg16Gly and Gln27Glu polymorphisms in ADRB2 gene with CF´s severity and bronchodilator response.

The ACE gene D/I polymorphism as a modulator of severity of cystic fibrosis.

BACKGROUND: Cystic Fibrosis (CF) is a monogenic disease with complex expression because of the action of genetic and environmental factors. We investigated whether the ACE gene D/I polymorphism is associated with severity of CF. METHODS: A cross-sectional study was performed, from 2009 to 2011, at University of Campinas - UNICAMP. We analyzed 180 patients for the most frequent mutations in the CFTR gene, presence of the ACE gene D/I polymorphism and clinical characteristics of CF. RESULTS: There was an association of the D/D genotype with early initiation of clinical manifestations (OR: 1.519, CI: 1.074 to 2.146), bacterium Burkholderia cepacia colonization (OR: 3.309, CI: 1.476 to 6.256) and Bhalla score (BS) (p = 0.015). The association was observed in subgroups of patients which were defined by their CFTR mutation genotype (all patients; subgroup I: no mutation detected; subgroup II: one CFTR allele identified to mutation class I, II or III; subgroup III: both CFTR alleles identified to mutation class I, II and/or III). CONCLUSION: An association between the D allele in the ACE gene and the severity of CF was found in our study.

Polymorphisms in methylenetetrahydrofolate reductase gene (MTHFR) and the age of onset of sporadic colorectal adenocarcinoma.

BACKGROUND AND AIMS: Evidence is accumulating for a role of folate in the aetiology of colorectal cancer (CRC). The methylenetetrahydrofolate reductase (MTHFR) gene, involved in folate metabolism, is polymorphic in humans. Since it is unknown whether the MTHFR C677T and A1298C polymorphisms alter the risk for CRC, this was the aim of our study. MATERIALS AND METHODS: Genomic DNA from 102 sporadic colorectal adenocarcinoma (SCA) patients and 300 controls was analyzed by polymerase chain reaction followed by restriction digestion for the polymorphisms analyses. RESULTS/FINDINGS: The frequencies of MTHFR C677T and A1298C genotypes were similar in patients and controls. Similar overall risks for disease were seen in individuals with the distinct MTHFR genotypes. However, an excess of the MTHFR 677TT and 677CT genotypes was seen in patients under 50 years, compared with patients at an older age (19.2 vs 13.1% and 61.6 vs 39.5%, respectively; P = 0.04). The differences were more prominent when the frequency of the 677TT plus 677CT genotype was seen in both group of patients (80.8 vs 52.6%, respectively; P = 0.01), and in younger patients compared to controls (80.8 vs 52.3%, P < 0.01). Individuals with the combined genotype had 3.82-fold (95% confidence interval, 1.41-10.42) increased risk of developing SCA under 50 years, compared with those harboring the wild-type genotype. INTERPRETATION/CONCLUSION: These results suggest a role for the MTHFR 677TT plus 677CT genotype in increasing SCA diagnosed at a low age in southeastern Brazil, but additional studies with larger sample sizes should be carried out to clarify this issue.

[Association between alpha 1 antitrypsin deficiency and cystic fibrosis severity]. / Associação entre deficiência de alfa-1-antitripsina e a gravidade da fibrose cística.

OBJECTIVE: To ascertain the distribution of alpha 1 antitrypsin genotypes and correlate it with the severity of pulmonary disease in patients with cystic fibrosis. METHOD: A clinical and laboratory cross sectional study of 70 patients at the Universidade Estadual de Campinas teaching hospital. Cystic fibrosis diagnoses was confirmed by both clinical and laboratory methods. The severity of cystic fibrosis was evaluated by Shwachman score. All the patients were tested for the presence of S and Z alleles for alpha 1 antitrypsin deficiency using polymerase chain reaction. RESULTS: Nine (12.8%) patients were heterozygous for S or Z alleles or the heterozygote compound (SZ). No significant differences were found in clinical severity of Cystic fibrosis between genotypes of alpha 1 antitrypsin. No significant differences were found when the patients were divided according to the presence or absence of the DeltaF508 mutation. CONCLUSION: In this study, the first undertaken in Brazil into the association of alpha 1 antitrypsin deficiency and cystic fibrosis, we did not find an association between the deficiency and cystic fibrosis severity.

[Cystic fibrosis at a Brazilian center of excellence: clinical and laboratory characteristics of 104 patients and their association with genotype and disease severity]. / Fibrose cística em um centro de referência no Brasil: características clínicas e laboratoriais de 104 pacientes e sua associação com o genótipo e a gravidade da doença.

OBJECTIVE: To identify the clinical, laboratory and radiographic characteristics of the cystic fibrosis patients under care at Universidade Estadual de Campinas (UNICAMP) in the last decade of the twentieth century, and to investigate the association of these characteristics with genotype and severity of the disease as measured by the Shwachman score. METHODS: Descriptive, retrospective and cross-sectional study of the patients assisted at UNICAMP hospital's Cystic Fibrosis Clinic from July 1990 to July 2000. RESULTS: One hundred and four patients were studied; 53.8% male; 93.3% Caucasian; 89.4% presented with respiratory symptoms; 59.6% presented with digestive symptoms; 5.8% had meconium ileus; 4.8% had diabetes. The mean age at onset of symptoms was 3 months, and the mean age at diagnosis was 2 years and 4 months. At diagnosis, 69.9 and 56.6% of the patients had weight and height below 10th percentile, respectively; in 10.6%, sweat chloride was < 60 mEq/l. Staphylococcus aureus was found in 80.2%, Pseudomonas aeruginosa in 76%, and Burkholderia cepacia in 5.2%. DeltaF508 homozygosis was observed in 18.75%, whereas 62.50% of the patients were DeltaF508 heterozygous. A moderate/severe Shwachman score was found in 15.7%. Eighteen patients died in that period (17.3%). The mean age at death was 7 years and 8 months; median survival after diagnosis was 18 years and 4 months. Patients who have at least one DeltaF508 mutation have more frequent alterations in fecal fat levels when compared to patients who do not have this mutation (p < 0.05). There were no differences in any parameter between DeltaF508 homozygous and heterozygous patients. CONCLUSIONS: The clinical and laboratory characteristics of the 104 patients studied were similar to the characteristics described for patients in other countries. Exceptions are the higher age at diagnosis and lower survival. Our results support the recommendation for early diagnosis and the need for more treatment opportunities in the population of cystic fibrosis patients.

Fibrose cística em um centro de referência no Brasil: características clínicas e laboratoriais de 104 pacientes e sua associação com o genótipo e a gravidade da doença / Cystic fibrosis at a Brazilian center of excellence: clinical and laboratory characteristics of 104 patients and their association with genotype and disease severity

OBJETIVO: Estudar as características clínicas, laboratoriais e radiográficas de pacientes fibrocísticos acompanhados na última década do século 20 na UNICAMP e verificar se existe associação com o genótipo e a gravidade da doença medida pelo escore de Shwachman. MÉTODOS: Estudo descritivo, retrospectivo e de corte transversal dos pacientes fibrocísticos acompanhados na UNICAMP, que tiveram atendimento entre julho de 1990 e julho de 2000. RESULTADOS: Foram estudados 104 pacientes: sexo masculino - 53,8 por cento; raça caucasóide - 93,3 por cento; comprometimento pulmonar - 89,4 por cento, comprometimento digestivo - 59,6 por cento; íleo meconial - 5,8 por cento; diabetes melito - 4,8 por cento; mediana da idade de início dos sintomas - 3 meses; mediana da idade no diagnóstico - 2 anos e 4 meses; 69,9 e 56,6 por cento apresentavam peso e estatura abaixo do percentil 10, respectivamente, na época do diagnóstico; dosagem de cloro no suor < 60 mEq/l - 10,6 por cento; colonização: S. aureus - 80,2 por cento, P. aeruginosa - 76,0 por cento, B. cepacia - 5,2 por cento; delta F508 homozigoto - 18,75 por cento, deltaF508 heterozigoto - 62,5 por cento; escore de Shwachman moderado/grave - 15,7 por cento. Foram a óbito 18 pacientes (17,3 por cento); mediana de idade do óbito de 7 anos e 8 meses; sobrevida mediana após o diagnóstico no término do estudo de 18 anos e 4 meses. Os pacientes com a mutação deltaF508 apresentaram balanço de gordura nas fezes alterado com maior freqüência que os pacientes sem essa mutação (p < 0,05). Quando comparados os pacientes que apresentavam uma ou duas mutações deltaF508, nenhum parâmetro apresentou diferença estatisticamente significativa. CONCLUSÕES: As características clínicas e laboratoriais dos pacientes estudados foram semelhantes às descritas na população fibrocística de outros países, com algumas exceções, dentre as quais destacamos maior idade no diagnóstico e menor sobrevida. Desta forma, nossos dados permitem inferir que esforços para um diagnóstico precoce e maior oportunidade de tratamento necessitam ser dirigidos aos pacientes fibrocísticos.

Molecular diagnosis of Huntington disease in Brazilian patients

Huntington disease (HD) is a progressive neurodegenerative disorder with autosomal dominant inheritance, characterized by choreiform movements and cognitive impairment. Onset of symptoms is around 40 years of age and progression to death occurs in approximately 10 to 15 years from the time of disease onset. HD is associated with an unstable CAG repeat expansion at the 5' and of the IT15 gene. We have genotyped the CAG repeat in the IT15 gene in 44 Brazilian individuals (42 patients and 2 unaffected family members) belonging to 34 unrelated families thought to segregate HD. We found one expanded CAG allele in 32 individuals (76 per cent) belonging to 25 unrelated families. In these HD patients, expanded alleles varied from 43 to 73 CAG units and normal alleles varied from 18 to 26 CAGs. A significant negative correlation between age at onset of symptoms and size of the expanded CAG allele was found (r=0.6; p=0.0001); however, the size of the expanded CAG repeat could explain only about 40 per cent of the variability in age at onset (r2=0.4). In addition, we genotyped 25 unrelated control individuals (total of 50 alleles) and found normal CAG repeats varying from 16 to 33 units. The percentage of heterozigocity of the normal allele in the control population was 88 per cent. In conclusion, our results showed that not all patients with the "HD" phenotype carried the expansion at the IT15 gene. Furthermore, molecular diagnosis was possible in all individuals, since no alleles of intermediate size were found. Therefore, molecular confirmation of the clinical diagnosis in HD should be sought in all suspected patients, making it possible for adequate genetic counseling.

Diagnóstico pré-natal da talassemia beta / Prenatal diagnosis of beta thalassemia

Demosntramos nossa recente experiência na realizaçäo de diagnóstico pré-natal da talassemia beta no Hospital Universitário da Faculdade de Ciências Médicas da UNICAMP. O casal estudado tem um filho homozigoto para a talassemia beta e está em curso a segunda gestaçäo. A análise molecular mostra que o feto é heterozigoto para o alelo beta (C-T)