Farrer L A, O'Sullivan D M, Cupples L A, Growdon J H, Myers R H
Department of Neurology, Boston University School of Medicine, MA 02118.
Ann Neurol. 1989 May;25(5):485-93. doi: 10.1002/ana.410250511.
Life table methods were used to determine the relative risk of Alzheimer's disease (AD) in relatives of index cases with AD. Risk of AD was assessed in 967 first-degree relatives of 128 probands with clinically diagnosed AD and 572 first-degree relatives of a control group consisting of 84 subjects with Parkinson's disease (PD). Using a method that weights likelihood of correct diagnosis of AD, cumulative risk among AD relatives by age 93 was 24%, whereas relatives of the PD probands had a weighted risk of 16% by age 90. Overall, the total lifetime risk of developing dementia was similar among first-degree relatives of patients with AD and those of patients with PD. The age-specific risks were much different, however; from the age of 65 years to the age of 80 years, relatives of patients with AD had a twofold to fourfold increased risk of dementia. Equal risks were found for parents and siblings and for male and female relatives after adjustment for sex-specific patterns of survivorship. Relatives of probands with early-onset (less than or equal to 67 years) and late-onset (greater than 67 years) AD had equivalent risks of developing illness. Because onset age was found to cluster in families, the apparent increase in cumulative incidence for dementia in relatives of early-onset cases was likely due to relatives of the late-onset cases dying before developing illness.(ABSTRACT TRUNCATED AT 250 WORDS)
生命表方法用于确定阿尔茨海默病（AD）索引病例亲属患AD的相对风险。对128例临床诊断为AD的先证者的967名一级亲属以及由84例帕金森病（PD）患者组成的对照组的572名一级亲属进行了AD风险评估。采用一种权衡AD正确诊断可能性的方法，到93岁时，AD亲属的累积风险为24%，而PD先证者的亲属到90岁时的加权风险为16%。总体而言，AD患者的一级亲属和PD患者的一级亲属患痴呆症的终生总风险相似。然而，特定年龄的风险差异很大；从65岁到80岁，AD患者的亲属患痴呆症的风险增加了两倍到四倍。在根据性别特异性生存模式进行调整后，父母和兄弟姐妹以及男性和女性亲属的风险相等。早发型（小于或等于67岁）和晚发型（大于67岁）AD先证者的亲属患疾病的风险相当。由于发现发病年龄在家族中聚集，早发型病例亲属中痴呆症累积发病率的明显增加可能是由于晚发型病例的亲属在患病前死亡。（摘要截短于250字）
