ACE and meningococcal infection: Subjects carrying the ACE1 D allele were found to have approximately two-fold increased systemic ACE level, whereas those with the ACE1 II genotype have the lowest ACE expression.13 Previous studies reported that the ACE1 deletion allele is associated with increased risk and severity of community acquired pneumonia (CAP), acute respiratory distress syndrome (ARDS) and meningococcal disease in Caucasian children.14–16