Corder E H, Woodbury M A
Department of Medicine, Duke University Medical Center, Durham, NC 27710.
Genet Epidemiol. 1993;10(6):495-9. doi: 10.1002/gepi.1370100628.
Grade of membership analysis (GoM) may have particular relevance for genetic epidemiology. The method can flexibly relate genetic markers, clinical features, and environmental exposures to possible subtypes of disease termed pure types even when population allele frequencies and penetrance functions are not known. Hence, GoM may complement existing strategies that sometimes fail in the presence of heterogeneity or when case definition is not well established. To illustrate the method, individuals in the Seattle data set were evaluated with respect to affection status, age at onset, pedigree, sex, and genetic markers on chromosomes 19 and 21. Seven pure types were found which we have designated as: Early Onset, Late Onset, Probable, and Unaffected 1 to Unaffected 4.
隶属度分析（GoM）可能对遗传流行病学具有特殊意义。即使在群体等位基因频率和外显率函数未知的情况下，该方法也能灵活地将遗传标记、临床特征和环境暴露与称为纯类型的疾病可能亚型联系起来。因此，GoM可以补充现有策略，这些策略有时在存在异质性或病例定义不明确时会失效。为了说明该方法，对西雅图数据集中的个体在患病状态、发病年龄、家系、性别以及19号和21号染色体上的遗传标记方面进行了评估。发现了七种纯类型，我们将其指定为：早发型、晚发型、可能型以及未患病1至未患病4型。
