Genetic Epidemiology

这个遗传流行病学项目中的许多调查都来自于对癌症高危家庭或其他病因学研究的观察。对哥伦比亚特区大都市地区犹太人口调查数据的分析仍在继续。评估了乳腺癌后发生第二种癌症的风险。与非携带者相比，突变携带者患对侧乳腺癌的风险并不显著高。然而，第二次卵巢癌的风险更高。回顾56例髓母细胞瘤患者和159例急诊室对照组的头颅CT表现，发现9%的髓母细胞瘤患者没有分流管，16%的患者有分流管，10%的急诊室对照组有假钙化。然而，只有两名同时患有髓母细胞瘤和新生基底细胞癌综合征的患者在诊断期表现出假性钙化。在Beckwith-Wiedemann综合征患者中，大约25%的人有非恶性肾脏异常，包括髓质肾囊肿、盏憩室、肾积水和肾结石。作为刚刚完成的DCEG对成年脑瘤患者的全面病例对照研究的后续行动，正在对480例符合条件的胶质瘤病例的父母、兄弟姐妹和成年子女进行以家庭为基础的研究。亲属将接受关于个人和家庭、病史和其他风险因素的面谈，并将被要求提供口腔细胞作为DNA来源。在关联性研究和分析中，这些亲属将被用作胶质瘤病例的对照，以评估遗传易感性和环境暴露对胶质瘤和病因相关肿瘤风险的作用。综述了检测基因-环境相互作用的流行病学和遗传学方法。在共同遗传和/或环境因素的研究中，传统的流行病学方法有足够的能力来检测相互作用。然而，对罕见因素的研究可能需要替代研究设计，如多阶段抽样、反匹配或病例-病例设计。

Many of the investigations in this genetic epidemiology project arise from observations in families at high risk of cancer or in other etiologic studies. Analyses of the data from the survey of the Jewish population in the metropolitan D.C. area continued. Risks of second cancers following breast cancer were assessed. The risk of contralateral breast cancer was not significantly higher among mutation carriers compared to noncarriers. Risk of a second ovary cancer, however, was higher. Retrospective review of cranial CT studies in 56 patients with medulloblastoma and 159 emergency room controls revealed that 9% of medulloblastoma patients without shunts, 16% with shunts, and 10% of emergency room controls had falx calcification. Only the two patients with both medulloblastoma and the nevoid basal cell carcinoma syndrome, however, demonstrated falx calcification in the peridiagnostic period. Among individuals with Beckwith-Wiedemann syndrome, approximately 25% have nonmalignant renal abnormalities including medullary renal cysts, caliceal diverticula, hydronephrosis and nephrolithiasis. As a follow-up to a just completed DCEG comprehensive case-control study of adults with brain tumors, a family-based study of the parents, siblings and adult children of the 480 eligible glioma cases is being conducted. Relatives will be interviewed about personal and family medical history and other risk factors and will be asked to provide buccal cells as a source of DNA. The relatives will be used as controls for the glioma cases in association studies and in analyses to evaluate the roles of genetic susceptibility and environmental exposures on the risk of gliomas and etiologically related tumors. Epidemiologic and genetic approaches for examining gene-environment interaction were reviewed. Traditional epidemiologic approaches have sufficient power to detect interaction in studies of common genetic and/or environmental factors. Studies of rare factors, however, will likely require alternative study designs such as multi-stage sampling, countermatching or case-case designs.