ABSTRACT
This chapter focuses on one particular condition, chronic obstructive pulmonary disease (COPD). COPD, with its high prevalence in the population, provides an appropriate "prototype chronic lung disease" for the study of familial aggregation. COPD is a heterogeneous disorder that includes emphysema, chronic bronchitis, and mixtures (combinations) of the two. Aside from the early reports heavily influenced by clinical impression, or involving single pedigrees or pedigree collections, very few publications suggest a simple genetic basis for the observed familial aggregation, without indicating the likelihood of the interaction of extrinsic agents with the hereditary component. Moreover, there was a high prevalence of COPD in female relatives (irrespective of whether they smoked), which did not appear in the female controls. For the study of familial aggregation of COPD, the classical genetic methods, including pedigree studies, tests of specific hypotheses, and twin studies, are clearly inadequate as the sole means of evaluating genetic involvement.
