Lung Cancer and Pulmonary Tuberculosis - A Comparative Population-Genetic Study

Several host genes proven to contribute to active tuberculosis (TB) and some of the localized major susceptibility loci, which influence lung cancer (LC) risk, are of considerable scientific interest, but do not confer high enough risk to be clinically relevant. Assuming that these diseases are genetically controlled, we hypothesized that retreat from optimal homozygosity level, as well as a changed variability among the patients, could be the populationgenetic parameter for prediction of illness. We performed a homozygous-recessive-characters (HRCs) test based analysis of the presence, distribution and individual combination of 23 selected genetically-controlled morpho-physiological traits in groups of LC patients, patients with pulmonary TB and healthy control subjects. This study showed: i) a statistically significant difference of the middle values of genetic homozygosity between both patients groups and the control group, ii) differences in the type of distribution, and iii) differences in the presence of certain individual combinations of such traits. The frequency of blood group O was significantly decreased in the TB group compared to the general population. According to their population-genetic structure, LC patients, TB patients and healthy controls represent three different groups. The retreat from optimal homozygosity level towards decrease that we found in both LC and TB patients support the influence of a dominant factor in development of these diseases.