Robust inference for variance components models in families ascertained through probands: II. Analysis of spirometric measures

✍ Scribed by T. H. Beaty; K. Y. Liang; S. Seerey; B. H. Cohen; D. C. Rao

• Publisher: John Wiley and Sons
• Year: 1987
• Tongue: English
• Weight: 568 KB
• Volume: 4
• Category: Article
• ISSN: 0741-0395
• DOI: 10.1002/gepi.1370040306

✦ Synopsis

Three spirometric measures of pulmonary function were used to estimate genetic and nongenetic components of variance for 781 members of 158 families ascertained through a proband with obstructive pulmonary disease. Forced expiratory volume in 1 sec (FEV1), forced vital capacity (FVC), and the ratio of these two (FEVl/FVC) were adjusted for age, sex, race, smoking, and height and used in a robust approach to estimate variance components after conditioning on the proband's observed value. The best fitting model for both residual FEV1/FVC and FEVl included an additive genetic component representing 25 % and 9 % of the variation in these two traits, respectively. In addition, there was a significant correlation between parents in residual FEVl/FVC, and a component shared among full sibs was statistically significant for residual FEV1. No evidence of a genetic component for residual FVC was found in this analysis. Although these results agree with previous reports based on other populations in showing a substantial degree of direct genetic control over spirometric measures of pulmonary function, they also raise the possibility of etiologic heterogeneity.