[1] Univ Fed Rio Grande do Sul, Inst Biociencias, Dept Genet, BR-90049 Porto Alegre, RS, Brazil
[2] Univ Fed Rio Grande do Sul, Fac Med, Dept Psychiat, Porto Alegre, RS, Brazil
[3] Univ Fed Rio Grande do Sul, Inst Matemat, Dept Stat, Porto Alegre, RS, Brazil