Association study. A: Map of the KRT8/KRT18 region on 12q13 showing the investigated microsatellite KRT8Sat and six SNPs. B, C: Results of the association study. Uncorrected P-values are shown for single markers (open circles), two- (red), three- (orange), four- (yellow) and five- (green) marker-haplotypes, describing adjacent and distant combinations of 6 SNPs and one microsatellite. Please note that some haplotype combinations are not visible in this plot as identical values will not show in an overlay. B: P values for comparison of haplotype distributions from concordant mildly affected (CON+; 13 families) to concordant severely affected (CON-; 12 families). Pbest = 0.00131 is observed for marker rs2035875. Pcorr = 0.0185 (corrected for simultaneous analysis of seven markers) . C: P values for comparison of diplotype distributions from patients classified by their basic defect through intestinal current measurement (ICM). Comparison was done between patients who do not exhibit residual chloride secretion (ICM no Res., 14 families) and patients who show CFTR mediated residual chloride secretion (ICM CFTR Res., 22 families). Pbest = 0.0004 is observed for the two- marker-combination rs4300473-KRT8Sat and the three-marker-combinations rs4300473-rs2035875-KRT8Sat, rs1907671-rs2035875-KRT8Sat, rs1907671-rs4300473-KRT8Sat as well as the four-marker-combination rs1907671-rs4300473-rs2035875-KRT8Sat. Pcorr = 0.0069 (corrected for simultaneous analysis of seven markers) .