No, she didn't say it was genetic... but that certain people are more susceptible and that is why certain geographic areas have higher incidence than others. My sister actually caught it from an irish cleaner who used to help my mum clean the house so I realise it is infective. The genetic component came from a link to the geographical areas. I know that even in the 1980s there were certain parts of London linked to TB, of course some were due to influx of immigrants carrying it, but some areas were not explainable and health workers were quite surprised by the figures. I guess the question is more that is the immune system more compromised in these areas for any other reason than housing, poor healthcare and sanitation etc. Are some peoples immune systems weaker than others due to genetics? Just a thought.