Genetic & Environmental Risk Factors in Asthma Severity

在过去的二十年中，儿童哮喘发病率急剧上升，其中西班牙裔和非洲裔美国人的发病率不成比例。已知环境因素（过敏原、真菌、环境烟草烟雾、空气污染物、冷空气等）与儿童哮喘严重程度有关。最近，遗传因素被认为是哮喘严重程度的重要决定因素。然而，对基因内特定突变与特定环境因素的相互作用知之甚少，尽管它对了解哮喘严重程度至关重要。在这个应用程序中，我们寻求扩大我们的哮喘严重程度研究，以检查基因-环境相互作用在改变哮喘严重程度。哮喘儿童（14%为黑人，27%为西班牙裔，55%为白人，4%为其他人种，16%为受教育程度低于12年的母亲）目前正在接受跟踪调查，以验证仔细量化室内过敏原暴露（室内尘螨，猫，狗，蟑螂和真菌）和空气污染物暴露(环境中的烟草烟雾，二氧化氮，亚硝酸，臭氧，细颗粒质量和花粉)与哮喘严重程度（每日呼吸系统症状、药物使用、卫生保健服务和肺功能的利用）有关，在1002名5至12岁的被医生诊断为哮喘的儿童中，他们的健康状况、家族史、家庭环境和潜在的混杂因素被仔细地描述。在本应用中，我们将研究过敏原、ETS和其他空气污染物暴露的各自作用，以及β 2肾上腺素能受体（Arg 16-Gly或Gln27-Glu）和IL-4基因启动子区域多态性的存在，特别是TT多态性，在控制儿童过敏状态的同时，在哮喘严重程度中。虽然几个候选基因已被确定为哮喘严重程度的潜在遗传决定因素，但我们选择β 2- ar和IL-4多态性作为该人群中检测的初始基因，因为它们与哮喘严重程度有关。通过收集和储存血液样本，其他候选基因可以被检查，因为它们是优先考虑的。我们对大量不同哮喘儿童人群的环境暴露和危险因素进行了广泛的表征，提供了一个独特的人群，其中可以检查哮喘严重程度中的基因-环境相互作用。本研究将为优先考虑环境干预措施以降低儿童哮喘发病率提供依据。

Over the past two decades asthma morbidity among children has increased dramatically, with disproportionate morbidity among Hispanic and African-Americans. Environmental factors (allergens, fungi, environmental tobacco smoke, air contaminants, cold air, etc.) are known to be associated with asthma severity in children. More recently genetic factors have been proposed as important determinants in the severity of asthma. The interaction of specific mutations within genes with specific environmental factors, however, is poorly understood despite its crucial importance in understanding asthma severity. In this application we seek to expand our asthma severity study to examine the gene-environment interactions in modifying asthma severity. The asthmatic children (14 percent Black, 27 percent Hispanic, 55 percent, Caucasian, 4 percent Other and 16 percent of mothers with an education level of less than 12 years of schooling) are currently being followed to test the hypothesis that carefully quantified indoor allergen exposures (house dust mite, cat, dog, cockroach and fungi) and air contaminant exposures (environmental tobacco smoke, nitrogen dioxide, nitrous acid, ozone, fine particle mass and pollen) are associated with asthma severity (daily respiratory symptoms, medication use, and utilization of health care services and lung function) in a population of 1,002 physician diagnosed asthmatic children between 5 and 12 years of age whose health status familial history, home environment, and potential confounders are carefully characterized. In this application we will investigate the respective roles of allergens, ETS and other air contaminant exposures and the presence of polymorphisms in the beta2 adrenergic receptor (Arg 16-Gly or Gln27-Glu) and in the promoter region of the IL-4 gene, particularly the TT polymorphism, in asthma severity while controlling for allergic status of the child. Although several candidate genes have been identified as potential genetic determinants of asthma severity, we chose beta2-AR and IL-4 polymorphisms as the initial genes to examine in this population because they have been linked to asthma severity. By collecting and storing blood samples, other candidate genes could be examined, as they are prioritized. Our extensive characterization of environmental exposures and risk factors for a large diverse population of asthmatic children, provide a unique population within which gene-environment interactions in the severity of asthma can be examined. This study will provide a basis to prioritizing environmental interventions to reduce asthma morbidity in children.