Project description:Large chromosomal rearrangements, duplications, and inversions are relatively common in mammalian genomes. Here we report interesting features of DNA strands flanking a Multiple Sclerosis (MS) susceptibility locus on Chromosome 17q24. During the positional cloning process of this 3-Mb locus, several markers showed a radiation hybrid clone retention rate above the average (1.8-fold), suggestive for the existence of duplicated sequences in this region. FISH studies demonstrated multiple signals with three of the tested regional BACs, and 24 BACs out of 187 showed evidence for duplication in shotgun sequence comparisons of the 17q22-q24 region. Specifically, the MS haplotype region proved to be flanked by palindromic sequence stretches and by long segmental intrachromosomal duplications in which highly homologous DNA sequences (>96% identity) are present at both ends of the haplotype. Moreover, the 3-Mb DNA segment, flanked by the duplications, is inverted in the mouse genome when compared with the orientation in human and chimp. The segmental duplication architecture surrounding the MS locus raises the possibility that a nonallelic homologous recombination between duplications could affect the biological activity of the regional genes, perhaps even contributing to the genetic background of MS.
Project description:Sex discordance in asthma prevalence has been previously reported, with higher prevalence in males before puberty, and in females after puberty; the adolescent "switch". However, cross-sectional studies have suggested a narrowing of this discordance in recent decades. We used a combination of cross-sectional and longitudinal modelling to examine sex differences in asthma, wheeze and longitudinal wheezing phenotypes in two UK birth cohorts, the Avon Longitudinal Study of Parents and Children (ALSPAC; born 1991-92 with data from age 0-18 years) and the Millennium Cohort Study (MCS; born 2000-02 with data from age 3-10 years). We derived measures of asthma and wheeze from questionnaires completed by mothers and cohort children. Previously-derived ALSPAC wheezing phenotype models were applied to MCS. Males had a higher prevalence of asthma at 10.7 years in ALSPAC (OR 1.45 95%CI: 1.26, 1.66 n = 7778 for current asthma) and MCS (OR 1.42 95%CI: 1.29, 1.56 n = 6726 for asthma ever) compared to females, decreasing in ALSPAC after puberty (OR 0.94 95%CI: 0.79, 1.11 n = 5023 for current asthma at 16.5 years). In longitudinal models using restricted cubic splines, males had a clear excess for asthma in the last 12 months and wheeze in the last 12 months up until 16.5 years of age in ALSPAC. Males had an increased risk of all derived longitudinal wheezing phenotypes in MCS when compared to never wheeze and no evidence of being at lower risk of late wheeze when compared to early wheeze. By comparing data in two large, contemporary cohorts we have shown the persistence of sex discordance in childhood asthma, with no evidence that the sex discordance is narrowing in recent cohorts.
Project description:BACKGROUND: Because of shifts in the gender ratio and incidence and remission rates of asthma during the teen ages, the methodology of incidence studies among teenagers is important, i.e. if the time intervals between surveys are too long, the incident cases might not be properly identified. The aim was to study the impact of study design on the incidence rates of asthma and wheeze during the teen ages. METHODS: In a study about asthma and allergic diseases within the OLIN studies (Obstructive Lung Disease in northern Sweden), a cohort of school children (n = 3,430) was followed annually by questionnaire from age 8 yrs. In the endpoint survey (age 18 yrs) 2,582 (75% of original responders) participated. Incident cases from age 12-18 yrs were identified by two methods: annual questionnaire reports (AR) and baseline-endpoint surveys only (BE). RESULTS: The cumulative incidence of asthma and wheeze was significantly higher based on AR compared to BE. Compared to the incidence rates based on all the annual surveys, the calculated average annual rates based on BE were in general lower both among the boys and among the girls. There were no differences between boys and girls in incidence rates of asthma or wheeze during the early teen years. However, from the age of 15 years, the annual incidence rates were significantly or borderline significantly higher among girls than boys. At onset, the additional cases of current asthma identified by AR had significantly less severe asthma than those identified in BE (p < 0.02). CONCLUSION: the size of the incidence of asthma and wheeze during the teen ages was influenced by study design. By using the conventional prospective study design with longer follow-up time, the incidence was underestimated.
Project description:: Several researchers have assessed the utility of Impulse Oscillometry System (IOS) in diagnosing and evaluating the severity of respiratory diseases in childhood, but none has investigated the impact of the fluctuations of IOS parameters in an individualized manner. In this two-year prospective study, we aimed to longitudinally evaluate changes in airflow limitation and bronchodilator responsiveness in steroid-naïve four- to six-year-old children during a virus-induced wheezing episode, with IOS pulmonary resistance parameters set at 5 (R5) and 20 (R20) Hz. Moreover, feasibility and reproducibility, in addition to the diagnostic properties of these parameters were examined. Lung function was assessed every six weeks (baseline), within the first 48 hours following an acute wheezing episode (Day 0), after 10, and after 30 days. Forty-three out of 93 recruited children (4.5 ± 0.4 years old) experienced a wheezing episode during the study period. All children were able to perform the IOS effort in an acceptable and highly reproducible manner. R5 and R20 fluctuated independently of atopy, age, height, and weight. On Day 0, R5 values were significantly lower than the respective baseline values and returned to individual baseline levels within 10 days. Post-bronchodilation R5 values were similar to the baseline ones, reflecting a reversible airway obstruction on Day 0. Response to bronchodilation (?R5) was significantly more pronounced on Day 0. ?R5 values lower than -20.5% had a sensitivity of 70% and a specificity of 76% and could accurately identify up to 75% of the examined preschoolers. This study provides evidence in favor of the objective utility of IOS as an easy, highly reproducible, and sensitive technique to assess clinically significant fluctuations and bronchodilation responses suggestive of airflow limitation. Reference values although necessary are suboptimal, utilizing the personal best values as personal reference is useful and reliable.
Project description:BackgroundAlthough sexual dimorphism in wheeze and asthma prevalence are well documented, sex-specific risk factors for wheeze and longitudinal wheeze phenotypes have not been well elucidated.ObjectiveBy using a large prebirth cohort, this study aimed to identify sex-specific risk factors for wheeze from birth through midchildhood and identify distinct longitudinal wheeze phenotypes and the sex-specific risk factors associated with these phenotypes.MethodsMothers reported child wheeze symptoms over the past year approximately yearly on 9 occasions starting at age 1 year. We identified sex-specific predictors of wheeze, wheeze phenotypes, and sex-specific predictors of these phenotypes by using generalized estimating equations, latent class mixed models, and multinomial logistic analysis, respectively.ResultsA total of 1623 children had information on wheeze at 1 or more time points. Paternal asthma was a stronger predictor of ever wheezing in boys (odds ratio [OR], 2.15; 95% CI, 1.74-2.66) than in girls (OR, 1.53; 95% CI, 1.19-1.96; P for sex by paternal asthma interaction = .03), whereas being black or Hispanic, birth weight for gestational age z score, and breast-feeding duration had stronger associations among girls. We identified 3 longitudinal wheeze phenotypes: never/infrequent wheeze (74.1%), early transient wheeze (12.7%), and persistent wheeze (13.1%). Compared with never/infrequent wheeze, maternal asthma, infant bronchiolitis, and atopic dermatitis were associated with persistent wheeze in both sexes, but paternal asthma was associated with persistent wheeze in boys only (OR, 4.27; 95% CI, 2.33-7.83; P for sex by paternal asthma interaction = .02), whereas being black or Hispanic was a predictor for girls only.ConclusionWe identified sex-specific predictors of wheeze and longitudinal wheeze patterns, which might have important prognostic value and allow for a more personalized approach to wheeze and asthma treatment.
Project description:BackgroundThe Asthma Predictive Index (API) and persistent wheezing phenotypes are associated with childhood asthma, but previous studies have not assessed their ability to predict objectively confirmed asthma.ObjectiveTo determine whether the University of Cincinnati API Index (ucAPI) and/or persistent wheezing at age 3 can accurately predict objectively confirmed asthma at age 7.MethodsData from the Cincinnati Childhood Allergy and Air Pollution Study, a high-risk prospective birth cohort, was used. Asthma was defined as parent-reported or physician-diagnosed asthma objectively confirmed by a change in FEV1 of ≥12% after bronchodilator or a positive methacholine challenge (PC20 ≤ 4 mg/mL); or as prior treatment with daily asthma controller medication(s). Multivariate logistic regression was used to investigate the relationship between confirmed asthma at age 7 and a positive ucAPI (adapted and modified from prior published API definitions) and persistent wheezing at age 3.ResultsAt age 7, 103 of 589 children (17.5%) satisfied the criteria for asthma. Confirmed asthma at age 7 was significantly associated with a positive ucAPI (adjusted odds ratio [aOR] 13.3 [95% CI, 7.0-25.2]; P < .01) and the persistent wheezing phenotype (aOR 9.8 [95% CI, 4.9-19.5]; P < .01) at age 3. Allergic persistent wheezing was associated with a significantly higher risk of asthma (aOR 10.4 [95% CI, 4.1-26.0]; P < .01) than nonallergic persistent wheezing (aOR 5.4 [95% CI, 2.04-14.06]; P < .01).ConclusionBoth a positive ucAPI and persistent wheeze at age 3 were associated with objectively confirmed asthma at age 7; however, the highest risk was associated with ucAPI. These results demonstrate the ucAPI as a clinically useful tool for predicting future asthma in school-age children.
Project description:Asthma is an inflammatory disease of the airways characterised by episodic airway obstruction resulting in cough, episodic shortness of breath. It is, and is clinically and physiologically heterogeneous. It is estimated that around 300 million people worldwide have the diseaseare diagnosed with asthma, including up to 20% of children (Asher et al, 2006), with 5–10% of these children believed to have severe or difficult-to-treat asthma. Asthma has often been classified in terms of severity and based on clinical diagnostic criteria, but it is now apparent that the heterogeneity that exists at the physiological level is also a feature of the underlying pathological mechanisms (Lotvall et al, 2011). The aim of this study was to identify blood transcriptomics profiles for children diagnosed with asthma or wheeze, and establish whether these profiles suggested endotypes or mechanisms that could underlie disease, or be related to disease severity, in these children. Importantly, given that children are currently treated with the same medicines as adults, we also aimed to compare profiles of children to those of adults with asthma to help determine whether efforts should be directed to the development of medicines targeting pathways and mechanisms that may be unique to children. To this end, we used gene transcriptome data generated from blood samples from adults and children from the U-BIOPRED consortium to ask how similar or different the differential gene expression profiles were between groups of adults and pre-school or school-aged children with severe or mild-moderate asthma (or wheeze for the pre-school aged children) using current definitions. The Unbiased Biomarkers for the Prediction of Respiratory Disease Outcomes (U-BIOPRED) project was set up as a public-private partnership within the framework of the Innovative Medicines Initiative (IMI), engaging academia, the pharmaceutical industry and patient groups. The goal of this investigation was to identify transcript fingerprints in whole blood that characterize patients with severe asthma and to determine whether subgroups of severe asthmatics can be identified.
Project description:Background: Maternal vitamin D status during pregnancy may influence lung development and risk of childhood wheeze and asthma. We investigated the relationship between prenatal vitamin D and child asthma in a racially diverse cohort with a high burden of vitamin D insufficiency and child asthma.Materials and methods: We included mother-child dyads in the prenatal Conditions Affecting Neurocognitive Development and Learning in Early Childhood (CANDLE) cohort (2006-2011, Shelby County, Tennessee). Maternal plasma vitamin D [25(OH)D] was measured from second trimester (n = 1091) and delivery specimens (n = 907). At age 4-6 years, we obtained parent report of current child wheeze (symptoms within the past 12 months) and asthma (physician diagnosis and/or medication or symptoms within the past 12 months). We used multivariable logistic regression to assess associations of 25(OH)D and child wheeze/asthma, including an interaction term for maternal race.Results: Median second trimester 25(OH)D levels were 25.1 and 19.1 ng/ml in White (n = 366) and Black women (N = 725), respectively. We detected significant interactions by maternal race for second-trimester plasma 25(OH)D and child current wheeze (p = .014) and asthma (p = .011). Odds of current wheeze and asthma decreased with increasing 25(OH)D in dyads with White mothers and increased in dyads with Black mothers, e.g. adjusted odds ratio (95% confidence interval) for asthma: 0.63 (0.36-1.09) and 1.41 (1.01-1.97) per interquartile range (15-27 ng/ml 25[OH]D) increase, respectively. At delivery, protective associations in White dyads were attenuated.Conclusion: We detected effect modification by maternal race in associations between prenatal 25(OH)D and child wheeze/asthma. Further research in racially diverse populations is needed.
Project description:In a genome-wide scan (GWS) of 175 multiplex prostate cancer (PCa) families from the University of Michigan Prostate Cancer Genetics Project (PCGP), linkage was observed to markers on chromosome 17q21-24, a region that includes two breast cancer susceptibility genes, BRCA1 and BRIP1. BRIP1 is a Fanconi anaemia gene (FANCJ) that interacts with the BRCT domain of BRCA1 and has a role in DNA damage repair. Protein truncating mutations in BRIP1 have been identified in hereditary breast and ovarian cancer families, and a recent report suggested that a recurrent truncating mutation (R798X) may have a role in PCa susceptibility.We examined the role of BRIP1 mutations in hereditary PCa through sequence analysis of 94 individuals from PCGP families showing linkage to 17q.A total of 24 single-nucleotide polymorphisms, including 7 missense variants but no protein truncating mutations, were observed.The data presented here suggest that BRIP1 truncating mutations are uncommon in PCa cases and do not account for the linkage to chromosome 17q observed in our GWS. Additional investigation is needed to determine the significance, if any, of the observed BRIP1 missense variants in hereditary PCa.
Project description:Exercise-induced wheeze (EIW) may identify a distinct population among asthmatics and give insight into asthma morbidity etiology. The prevalence of pediatric asthma and associated urgent medical visits varies greatly by neighborhood in New York City and is highest in low-income neighborhoods. Although increased asthma severity might contribute to the disparities in urgent medical visits, when controlling for health insurance coverage, we previously observed no differences in clinical measures of severity between asthmatic children living in neighborhoods with lower (3%-9%) versus higher (11%-19%) asthma prevalence. Among these asthmatics, we hypothesized that EIW would be associated with urgent medical visits and a child's neighborhood asthma prevalence.Families of 7- to 8-year-old children were recruited into a case-control study of asthma through an employer-based health insurance provider. Among the asthmatics (n = 195), prevalence ratios (PRs) for EIW were estimated. Final models included children with valid measures of lung function, seroatopy, and waist circumference (n = 140).EIW was associated with urgent medical visits for asthma (PR, 2.29; P = .021), independent of frequent wheeze symptoms. In contrast to frequent wheeze, EIW was not associated with seroatopy or exhaled NO, suggesting a distinct mechanism. EIW prevalence among asthmatics increased with increasing neighborhood asthma prevalence (PR, 1.09; P = .012), after adjustment for race, ethnicity, maternal asthma, environmental tobacco smoke, household income, and neighborhood income.EIW may contribute to the disparities in urgent medical visits for asthma between high- and low-income neighborhoods. Physicians caring for asthmatics should consider EIW an indicator of risk for urgent medical visits.