Although high population abundance represents a risk factor for MTC infection and disease progression32,39 and therefore TB-driven selection36, the possible increase of genetic drift during the 2004/05 demographic event may also have had an impact on several genomic regions that interfered with the host’s ability to express certain gene variants directly involved in the immune response mechanisms such as IGSF2146, BDNF/NT347 and NTRK247 (Fig. 5). This evidence concerns the gene BDNF and tuberculosis.