Susceptibility to CAP related to SFTPA1, SFTPA2 and SFTPD gene variants Seven non-synonymous SNPs were genotyped across the region containing the SFTPD, SFTPA1 and SFTPA2 genes ( Table 1) . None of the SNPs showed a significant deviation from Hardy-Weinberg equilibrium in controls. Several major alleles were overrepresented in controls compared with patients, but only SFTPA1 aa50-G, SFTPA2 aa9-A and aa91-G remained significant after Bonferroni correction for multiple comparisons. A dominant effect of SFTPA2 aa9-A, and a recessive effect of SFTPA1 aa50-G and aa219-C as well as SFTPA2 aa223-C were associated with a lower risk of CAP (see Table 1 ). When haplotypes were inferred, seven different haplotypes were found for SFTPA1 and eight for SFTPA2 (see Table 2 ). All haplotypes except 6A 5 , 6A 15 , 1A 10 and 1A 13 had frequencies higher than 1% in our population. The most frequent haplotype for SFTPA1 and SFTPA2 were respectively TGC and AGC, which correspond mainly with the 6A 2 and 1A 0 haplotypes respectively. The frequencies of both haplotypes were significantly lower in patients compared to controls (P = 0.0009, OR = 0.78; 95% confidence interval (CI) 0.67 to 0.91, for SFTPA1 6A 2 . P = 0.002, OR = 0.79; 95% CI 0.68 to 0.92, for SFTPA2 1A 0 ), even when Bonferroni correction was applied. Several haplotypes were overrepresented in patients compared with controls, but only 1A 10 (P = 0.00007, OR = 6.58; 95% CI 2.24 to 26.22) remained significant after Bonferroni correction. For the observed odd-ratios, the power of the tests with a significance level of 1% were 84.16%, 79.09% and 94.04% for the haplotypes 6A 2 , 1A 0 and 1A 10 respectively. In addition, dominant and recessive models showed a significant dominant effect on CAP susceptibility for haplotypes 6A 3 , 1A 0 , 1A 7 and 1A 10 and a recessive effect for haplotype 6A 2 (see Table 2 ).