Modifier genes analysis by PCR-RFLP adapted from previously published techniques [21]–[24].

<p>Modifier genes analysis by PCR-RFLP adapted from previously published techniques <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0090945#pone.0090945-Sandford1" target="_blank">[21]</a>–<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0090945#pone.0090945-Chen1" target="_blank">[24]</a>.</p

Mutations included in the kits used for the molecular diagnosis of CF patients.

<p>Mutations included in the kits used for the molecular diagnosis of CF patients.</p

TNF1/TNF2 association values using dominant, additive and recessive models.

1<p>odds ratio.</p>2<p>Chi-Squared P.</p>3<p>Bonf. P.</p>4<p>Correl/Trend P.</p

CFTR genotype frequencies from 81 Mexican CF patients.

<p>X: unknown allele.</p

PCR-RFLP for the modifier genes analysis.

<p>1A: the 134 bp PCR product from exon 1 of the MBL1 gene was digested with <i>Mwo</i> I, <i>Ban</i> I and <i>Mbo</i> II for detection of polymorphisms in the 52, 54 and 57 codons. 1B: the 816 bp PCR product from promoter region of the IL-8 gene was digested with <i>Mfe</i> I for detection of the −251 polymorphism. 1C: the 142 bp PCR product from promoter region of the TNFα gene was digested with <i>Nco</i> I for detection of the −308 polymorphism (TNF2); the 98 bp PCR product from the SERPINA1 gene was digested with <i>Taq</i> I^α for detection of the S genetic variant; the 144 bp PCR product from the SERPINA1 gene was digested with <i>Taq</i> I^α enzyme for detection of the Z genetic variant. Mw1 is the molecular marker pBs+<i>Msp</i> I, Mw2 is the molecular marker λ+<i>Pst</i> I. P_MBL, P_IL8, P_TNF, P_AATS and P_AATZ are undigested PCR products. The Z allele was not detected.</p

Modifier gene genotype frequencies (%) in CF patients and control subjects; OR, Hardy–Weinberg Equilibrium (HWE) and results of the association test with Dominant Model <i>P</i>-values.

<p>CF, cystic fibrosis; OR, Odds Ratio; CI, confidence interval.</p>a<p>TNF1 −308 G: (dd) vs. (DD, Dd),</p>b<p>TNF2 −308 A: (DD, Dd) vs. (dd).</p><p>HW-P: <i>P</i>-value for the Hardy-Weinberg equilibrium.</p><p>X² Bonf. P = Chi squared test with a Bonferroni-corrected <i>P</i>-value.</p