Genetic epidemiology of the Mitsuda reaction in leprosy.

This study comprised 544 nuclear families with 2,925 individuals tested for the Mitsuda reaction, from the Campinas region in Brazil. Segregation analyses suggest the segregation of a major gene (chi 2(1) = 0.07 - 0.07 = 0, p = 1), by failing to reject the hypothesis of Mendelian transmission and by rejecting the hypothesis of nontransmission of a major gene (chi 2(3) = 0.07 - 0.0 = 0.07, p > 0.99; chi 2(2) = 198.28 - 0.0 = 198.28, p < 0.0001).