Table 3.

RR of TGCC associated with maternal and offspring genotypes among case-parent triads and dyads, by locus

Gene and polymorphism
CYP1A2 −163C>ACYP1B1Arg48GlyCYP1B1Leu432ValCYP1B1Asn453SerCYP3A4 −392A>GCYP3A5 6986A>G
Triads only
    Maternal (n)103101104104107101
    No. informative triads596159411830
        Reference1.01.01.01.01.01.0
        Heterozygote RR0.6 (0.2-1.7)1.3 (0.7-2.2)0.7 (0.3-1.4)0.8 (0.4-1.5)1.1 (0.4-3.0)0.8 (0.4-1.8)
        Homozygote RR0.9 (0.3-2.3)2.7 (0.9-7.9)0.9 (0.4-2.0)0.5 (0.1-2.6)1.1 (0.1-18)0.5 (0.0-5.3)
        P*0.0450.0860.4491.0001.0001.000
    Offspring
    No. informative triads656576431729
        Reference1.01.01.01.01.01.0
        Heterozygote RR0.7 (0.3-1.5)0.9 (0.5-1.5)1.0 (0.5-1.7)0.7 (0.4-1.2)7 (1.6-31)2.4 (1.1-5.6)
        Homozygote RR0.5 (0.2-1.2)0.9 (0.3-2.4)1.2 (0.6-2.6)UndefinedUndefinedUndefined
        P*0.1350.8491.0000.0770.0110.110
Triads and dyads
    Maternal (n)153150153153158151
        Reference1.01.01.01.01.01.0
        Heterozygote RR0.4 (0.2-1.0)1.4 (0.8-2.3)0.6 (0.3-1.1)0.9 (0.5-1.7)0.9 (0.4-2.1)0.8 (0.4-1.5)
        Homozygote RR0.6 (0.3-1.5)2.6 (1.1-6.3)0.8 (0.4-1.5)0.4 (0.1-2.1)0.9 (0.1-14)0.4 (0.0-4.2)
        P*0.0100.0050.1560.8970.9621.000
    Offspring
        Reference1.01.01.01.01.01.0
        Heterozygote RR0.7 (0.3-1.4)0.9 (0.5-1.4)1.2 (0.7-2.0)0.8 (0.5-1.3)5.2 (1.5-18)1.8 (0.9-3.6)
        Homozygote RR0.5 (0.2-1.2)1.0 (0.4-2.4)1.3 (0.6-2.6)0.2 (0.0-1.4)UndefinedUndefined
        P*0.0790.6771.0000.2730.0130.256
Definition of genotypes
    Reference groupCCCCCCAAAAGG
    HeterozygoteCACGCGAGAGGA
    HomozygoteAAGGGGGGGGAA
  • * To calculate Ps, we calculated twice the difference between the log likelihood of the model estimating maternal effects and that in which maternal (or offspring) associations with offspring TGCC risk are assumed to be zero and compared the result to a χ2 distribution with 1 df (CYP3A4 or CYP3A5 offspring heterozygote RRs) or 2 df (all other loci).

  • Because we observed no offspring who were homozygous for either the CYP3A4 −392G allele or the CYP3A5 6986A allele, we estimated the offspring associations imposing a dominant genetic model.