Significant results of carrier trait analyses.

1 Fisher's exact test.2The observed frequency of combined carriage (i.e. intersection) of the homozygous mutant alleles is relatively high compared the expected frequency (i.e. the frequency of one genotype multiplied by the other genotype; see table 1). The genotypes were retested and confirmed, and treated as empirical data.Abbreviations: SNP: single nucleotide polymorphism, BM: bacterial meningitis, MM: meningococcal meningitis, PM: pneumococcal meningitis, OR: Odds ratio, 95% CI: 95% confidence interval.