Evidence for a genetic basis to the enhanced total lung capacity of Andean highlanders.

The hypothesis that the enlarged lung volume of Andean highlanders has an important genetic basis was tested in a sample of 203 males and 166 females (10.0-29.9 years old) of Aymara ancestry who were residing in La Paz, Bolivia (3600 m). The measures of lung function included total lung capacity and its components, and skin reflectances were used as genetic markers. Examination of the relationships between each lung volume and skin reflectance and comparisons between skin color categories suggested that an increasing proportion of Aymara genes is associated with progressive increases in lung volume, which is consistent with the hypothesis that the enhanced lung volume of Andean highlanders is to some important extent influenced by genes. Because a previous analysis of the same sample indicated that the enhanced lung volume of Andean highlanders is also partly due to exposure to hypobaric hypoxia during the period of growth and development, it can be concluded that the enhanced lung volume is influenced by both environmental and genetic factors.