[Familial analysis of the in vitro behavior of human macrophages against Mycobacterium leprae].

The lysogenic capacity of human macrophages facing M. leprae in vitro may be dependent on an important genetic component. Although the family aggregation of the trait is demonstrated, this is a necessary but not sufficient condition to prove genetic influence. The data do not fit some simple genetic models (autosomal dominant or incompletely dominant gene; dominant or recessive sex-linked gene). The results obtained are consistent with the hypothesis that the macrophages' lysogenic capacity is mainly due to a major gene with variable expressivity. This hypothesis may be too simple to account for the whole variability detected and therefore must be considered just as a working hypothesis.